terminfo

terminfo(5) File formats terminfo(5)

NAME

   terminfo - terminal capability database

SYNOPSIS

   /etc/terminfo/*/*

DESCRIPTION

   Terminfo is a database describing terminals, used by screen-oriented programs such as nvi(1), lynx(1), mutt(1), and other curses applications, using high-level calls to libraries such
   as ncurses(3NCURSES).  It is also used via low-level calls by non-curses applications which may be screen-oriented (such as clear(1)) or non-screen (such as tabs(1)).

   Terminfo describes terminals by giving a set of capabilities which they have, by specifying how to perform screen operations, and by specifying padding requirements and initialization
   sequences.

   This document describes ncurses version 6.5 (patch 20250216).

terminfo Entry Syntax

   Entries in terminfo consist of a sequence of fields:

      Each field ends with a comma , (embedded commas may be escaped with a backslash or written as \054).

      White space between fields is ignored.

      The first field in a terminfo entry begins in the first column.

      Newlines and leading whitespace (spaces or tabs) may be used for formatting entries for readability.  These are removed from parsed entries.

       The infocmp -f and -W options rely on this to format if-then-else expressions, or to enforce maximum line-width.  The resulting formatted terminal description can be read by tic.

      The first field for each terminal gives the names which are known for the terminal, separated by | characters.

       The  first  name  given  is  the  most  common  abbreviation  for  the  terminal  (its primary name), the last name given should be a long name fully identifying the terminal (see
       longname(3NCURSES)), and all others are treated as synonyms (aliases) for the primary terminal name.

       X/Open Curses advises that all names but the last should be in lower case and contain no blanks; the last name may well contain upper case and blanks for readability.

       This implementation is not so strict; it allows mixed case in the primary name and aliases.  If the last name has no embedded blanks, it allows that to be both an alias and a ver
       bose name (but will warn about this ambiguity).

      Lines beginning with a #” in the first column are treated as comments.

       While comment lines are valid at any point, the output of captoinfo and infotocap (aliases for tic) will move comments so they occur only between entries.

   Terminal names (except for the last, verbose entry) should be chosen using the following conventions.  The particular piece of hardware making up the terminal should have a root name,
   thus hp2621.  This name should not contain hyphens.  Modes that the hardware can be in, or user preferences, should be indicated by appending a hyphen and a mode  suffix.   Thus,  a
   vt100 in 132-column mode would be vt100-w.  The following suffixes should be used where possible:

   Suffix   Example     Meaning
   
   -nn      aaa-60      Number of lines on the screen
   -np      c100-4p     Number of pages of memory
   -am      vt100-am    With automargins (usually the default)
   -m       ansi-m      Mono mode; suppress color
   -mc      wy30-mc     Magic cookie; spaces when highlighting
   -na      c100-na     No arrow keys (leave them in local)
   -nam     vt100-nam   Without automatic margins
   -nl      hp2621-nl   No status line
   -ns      hp2626-ns   No status line
   -rv      c100-rv     Reverse video
   -s       vt100-s     Enable status line
   -vb      wy370-vb    Use visible bell instead of beep
   -w       vt100-w     Wide mode (> 80 columns, usually 132)

   For more on terminal naming conventions, see the term(7) manual page.

terminfo Capabilities Syntax

   The terminfo entry consists of several capabilities, i.e., features that the terminal has, or methods for exercising the terminal's features.

   After the first field (giving the name(s) of the terminal entry), there should be one or more capability fields.  These are Boolean, numeric or string names with corresponding values:

      Boolean capabilities are true when present, false when absent.  There is no explicit value for Boolean capabilities.

      Numeric capabilities have a #” following the name, then an unsigned decimal integer value.

      String capabilities have a = following the name, then an string of characters making up the capability value.

       String  capabilities  can  be split into multiple lines, just as the fields comprising a terminal entry can be split into multiple lines.  While blanks between fields are ignored,
       blanks embedded within a string value are retained, except for leading blanks on a line.

   Any capability can be canceled, i.e., suppressed from the terminal entry, by following its name with @ rather than a capability value.

Similar Terminals

   If there are two very similar terminals, one (the variant) can be defined as being just like the other (the base) with certain exceptions.  In  the  definition  of  the  variant,  the
   string capability use can be given with the name of the base terminal:

      The capabilities given before use override those in the base type named by use.

      If there are multiple use capabilities, they are merged in reverse order.  That is, the rightmost use reference is processed first, then the one to its left, and so forth.

      Capabilities given explicitly in the entry override those brought in by use references.

   A capability can be canceled by placing xx@ to the left of the use reference that imports it, where xx is the capability.  For example, the entry

          2621-nl, smkx@, rmkx@, use=2621,

   defines  a  2621-nl that does not have the smkx or rmkx capabilities, and hence does not turn on the function key labels when in visual mode.  This is useful for different modes for a
   terminal, or for different user preferences.

   An entry included via use can contain canceled capabilities, which have the same effect as if those cancels were inline in the using terminal entry.

Predefined Capabilities

   Tables of capabilities ncurses recognizes in a terminfo terminal type description and available to terminfo-using code follow.

      The capability name identifies the symbol by which the programmer using the terminfo API accesses the capability.

      The TI (terminfo) code is the short name used by a person composing or updating a terminal type entry.

       Whenever possible, these codes are the same as or similar to those of the ANSI X3.64-1979 standard (now superseded by ECMA-48, which uses identical or very similar names).  Seman
       tics are also intended to match those of the specification.

       terminfo codes have no hard length limit, but ncurses maintains an informal one of 5 characters to keep them short and to allow the tabs in the source file Caps to line up nicely.
       (Some standard codes exceed this limit regardless.)

      The TC (termcap) code is that used by the corresponding API of ncurses.  (Some capabilities are new, and have names that BSD termcap did not originate.)

      The description field attempts to convey the capability's semantics.

   The description field employs a handful of notations.

   (P)    indicates that padding may be specified.

   (P*)   indicates that padding may vary in proportion to the number of output lines affected.

   #i     indicates the ith parameter of a string capability; the programmer should pass the string to tparm(3NCURSES) with the parameters listed.

          If the description lists no parameters, passing the string to tparm(3NCURSES) may produce unexpected behavior, for instance if the string contains percent signs.

                                  Code
   Boolean Capability Name    TI        TC  Description
   ────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────
   auto_left_margin           bw        bw  cub1 wraps from column 0 to last column
   auto_right_margin          am        am  terminal has automatic margins
   no_esc_ctlc                xsb       xb  beehive (f1=escape, f2=ctrl C)
   ceol_standout_glitch       xhp       xs  standout not erased by overwriting (hp)
   eat_newline_glitch         xenl      xn  newline ignored after 80 cols (concept)
   erase_overstrike           eo        eo  can erase overstrikes with a blank
   generic_type               gn        gn  generic line type
   hard_copy                  hc        hc  hardcopy terminal
   has_meta_key               km        km  Has a meta key (i.e., sets 8th-bit)
   has_status_line            hs        hs  has extra status line
   insert_null_glitch         in        in  insert mode distinguishes nulls
   memory_above               da        da  display may be retained above the screen
   memory_below               db        db  display may be retained below the screen
   move_insert_mode           mir       mi  safe to move while in insert mode
   move_standout_mode         msgr      ms  safe to move while in standout mode
   over_strike                os        os  terminal can overstrike
   status_line_esc_ok         eslok     es  escape can be used on the status line
   dest_tabs_magic_smso       xt        xt  tabs destructive, magic so char (t1061)
   tilde_glitch               hz        hz  cannot print ~'s (Hazeltine)
   transparent_underline      ul        ul  underline character overstrikes
   xon_xoff                   xon       xo  terminal uses xon/xoff handshaking
   needs_xon_xoff             nxon      nx  padding will not work, xon/xoff required
   prtr_silent                mc5i      5i  printer will not echo on screen
   hard_cursor                chts      HC  cursor is hard to see
   non_rev_rmcup              nrrmc     NR  smcup does not reverse rmcup
   no_pad_char                npc       NP  pad character does not exist
   non_dest_scroll_region     ndscr     ND  scrolling region is non-destructive
   can_change                 ccc       cc  terminal can re-define existing colors
   back_color_erase           bce       ut  screen erased with background color
   hue_lightness_saturation   hls       hl  terminal uses only HLS color notation (Tektronix)
   col_addr_glitch            xhpa      YA  only positive motion for hpa/mhpa caps
   cr_cancels_micro_mode      crxm      YB  using cr turns off micro mode
   has_print_wheel            daisy     YC  printer needs operator to change character set
   row_addr_glitch            xvpa      YD  only positive motion for vpa/mvpa caps
   semi_auto_right_margin     sam       YE  printing in last column causes cr
   cpi_changes_res            cpix      YF  changing character pitch changes resolution
   lpi_changes_res            lpix      YG  changing line pitch changes resolution

                                  Code
   Numeric Capability Name    TI        TC  Description
   
   columns                    cols      co  number of columns in a line
   init_tabs                  it        it  tabs initially every # spaces
   lines                      lines     li  number of lines on screen or page
   lines_of_memory            lm        lm  lines of memory if > line. 0 means varies
   magic_cookie_glitch        xmc       sg  number of blank characters left by smso or rmso
   padding_baud_rate          pb        pb  lowest baud rate where padding needed
   virtual_terminal           vt        vt  virtual terminal number (CB/unix)
   width_status_line          wsl       ws  number of columns in status line
   num_labels                 nlab      Nl  number of labels on screen
   label_height               lh        lh  rows in each label
   label_width                lw        lw  columns in each label
   max_attributes             ma        ma  maximum combined attributes terminal can handle
   maximum_windows            wnum      MW  maximum number of definable windows
   max_colors                 colors    Co  maximum number of colors on screen
   max_pairs                  pairs     pa  maximum number of color-pairs on the screen
   no_color_video             ncv       NC  video attributes that cannot be used with colors

   The following numeric capabilities are present in the SVr4.0 term structure, but are not yet documented in the man page.  They came in with SVr4's printer support.

                                  Code
   Numeric Capability Name    TI        TC  Description
   ────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────
   buffer_capacity            bufsz     Ya  numbers of bytes buffered before printing
   dot_vert_spacing           spinv     Yb  spacing of pins vertically in pins per inch
   dot_horz_spacing           spinh     Yc  spacing of dots horizontally in dots per inch
   max_micro_address          maddr     Yd  maximum value in micro_..._address
   max_micro_jump             mjump     Ye  maximum value in parm_..._micro
   micro_col_size             mcs       Yf  character step size when in micro mode
   micro_line_size            mls       Yg  line step size when in micro mode
   number_of_pins             npins     Yh  numbers of pins in print-head
   output_res_char            orc       Yi  horizontal resolution in units per line
   output_res_line            orl       Yj  vertical resolution in units per line
   output_res_horz_inch       orhi      Yk  horizontal resolution in units per inch
   output_res_vert_inch       orvi      Yl  vertical resolution in units per inch
   print_rate                 cps       Ym  print rate in characters per second
   wide_char_size             widcs     Yn  character step size when in double wide mode
   buttons                    btns      BT  number of buttons on mouse
   bit_image_entwining        bitwin    Yo  number of passes for each bit-image row
   bit_image_type             bitype    Yp  type of bit-image device

                                  Code
   String Capability Name     TI        TC  Description
   ────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────
   back_tab                   cbt       bt  back tab (P)
   bell                       bel       bl  audible signal (bell) (P)
   carriage_return            cr        cr  carriage return (P*) (P*)
   change_scroll_region       csr       cs  change region to line #1 to line #2 (P)
   clear_all_tabs             tbc       ct  clear all tab stops (P)
   clear_screen               clear     cl  clear screen and home cursor (P*)
   clr_eol                    el        ce  clear to end of line (P)
   clr_eos                    ed        cd  clear to end of screen (P*)
   column_address             hpa       ch  horizontal position #1, absolute (P)
   command_character          cmdch     CC  terminal settable cmd character in prototype !?
   cursor_address             cup       cm  move to row #1 columns #2
   cursor_down                cud1      do  down one line
   cursor_home                home      ho  home cursor (if no cup)
   cursor_invisible           civis     vi  make cursor invisible
   cursor_left                cub1      le  move left one space
   cursor_mem_address         mrcup     CM  memory relative cursor addressing, move to row #1 columns #2
   cursor_normal              cnorm     ve  make cursor appear normal (undo civis/cvvis)
   cursor_right               cuf1      nd  non-destructive space (move right one space)
   cursor_to_ll               ll        ll  last line, first column (if no cup)
   cursor_up                  cuu1      up  up one line
   cursor_visible             cvvis     vs  make cursor very visible
   delete_character           dch1      dc  delete character (P*)
   delete_line                dl1       dl  delete line (P*)
   dis_status_line            dsl       ds  disable status line
   down_half_line             hd        hd  half a line down
   enter_alt_charset_mode     smacs     as  start alternate character set (P)
   enter_blink_mode           blink     mb  turn on blinking
   enter_bold_mode            bold      md  turn on bold (extra bright) mode
   enter_ca_mode              smcup     ti  string to start programs using cup
   enter_delete_mode          smdc      dm  enter delete mode
   enter_dim_mode             dim       mh  turn on half-bright mode
   enter_insert_mode          smir      im  enter insert mode
   enter_secure_mode          invis     mk  turn on blank mode (characters invisible)
   enter_protected_mode       prot      mp  turn on protected mode
   enter_reverse_mode         rev       mr  turn on reverse video mode
   enter_standout_mode        smso      so  begin standout mode
   enter_underline_mode       smul      us  begin underline mode
   erase_chars                ech       ec  erase #1 characters (P)
   exit_alt_charset_mode      rmacs     ae  end alternate character set (P)
   exit_attribute_mode        sgr0      me  turn off all attributes
   exit_ca_mode               rmcup     te  strings to end programs using cup
   exit_delete_mode           rmdc      ed  end delete mode
   exit_insert_mode           rmir      ei  exit insert mode
   exit_standout_mode         rmso      se  exit standout mode
   exit_underline_mode        rmul      ue  exit underline mode
   flash_screen               flash     vb  visible bell (may not move cursor)
   form_feed                  ff        ff  hardcopy terminal page eject (P*)
   from_status_line           fsl       fs  return from status line
   init_1string               is1       i1  initialization string
   init_2string               is2       is  initialization string
   init_3string               is3       i3  initialization string
   init_file                  if        if  name of initialization file
   insert_character           ich1      ic  insert character (P)
   insert_line                il1       al  insert line (P*)
   insert_padding             ip        ip  insert padding after inserted character
   key_backspace              kbs       kb  backspace key
   key_catab                  ktbc      ka  clear-all-tabs key
   key_clear                  kclr      kC  clear-screen or erase key
   key_ctab                   kctab     kt  clear-tab key
   key_dc                     kdch1     kD  delete-character key
   key_dl                     kdl1      kL  delete-line key
   key_down                   kcud1     kd  down-arrow key
   key_eic                    krmir     kM  sent by rmir or smir in insert mode
   key_eol                    kel       kE  clear-to-end-of-line key
   key_eos                    ked       kS  clear-to-end-of-screen key
   key_f0                     kf0       k0  F0 function key
   key_f1                     kf1       k1  F1 function key
   key_f10                    kf10      k;  F10 function key
   key_f2                     kf2       k2  F2 function key
   key_f3                     kf3       k3  F3 function key
   key_f4                     kf4       k4  F4 function key
   key_f5                     kf5       k5  F5 function key
   key_f6                     kf6       k6  F6 function key
   key_f7                     kf7       k7  F7 function key
   key_f8                     kf8       k8  F8 function key
   key_f9                     kf9       k9  F9 function key
   key_home                   khome     kh  home key
   key_ic                     kich1     kI  insert-character key
   key_il                     kil1      kA  insert-line key
   key_left                   kcub1     kl  left-arrow key
   key_ll                     kll       kH  lower-left key (home down)
   key_npage                  knp       kN  next-page key
   key_ppage                  kpp       kP  previous-page key
   key_right                  kcuf1     kr  right-arrow key
   key_sf                     kind      kF  scroll-forward key
   key_sr                     kri       kR  scroll-backward key
   key_stab                   khts      kT  set-tab key
   key_up                     kcuu1     ku  up-arrow key
   keypad_local               rmkx      ke  leave keyboard transmit mode
   keypad_xmit                smkx      ks  enter keyboard transmit mode
   lab_f0                     lf0       l0  label on function key f0 if not f0
   lab_f1                     lf1       l1  label on function key f1 if not f1
   lab_f10                    lf10      la  label on function key f10 if not f10
   lab_f2                     lf2       l2  label on function key f2 if not f2
   lab_f3                     lf3       l3  label on function key f3 if not f3
   lab_f4                     lf4       l4  label on function key f4 if not f4
   lab_f5                     lf5       l5  label on function key f5 if not f5
   lab_f6                     lf6       l6  label on function key f6 if not f6
   lab_f7                     lf7       l7  label on function key f7 if not f7
   lab_f8                     lf8       l8  label on function key f8 if not f8
   lab_f9                     lf9       l9  label on function key f9 if not f9
   meta_off                   rmm       mo  turn off meta mode
   meta_on                    smm       mm  turn on meta mode (8th-bit on)
   newline                    nel       nw  newline (behave like cr followed by lf)
   pad_char                   pad       pc  padding char (instead of null)
   parm_dch                   dch       DC  delete #1 characters (P*)
   parm_delete_line           dl        DL  delete #1 lines (P*)
   parm_down_cursor           cud       DO  down #1 lines (P*)
   parm_ich                   ich       IC  insert #1 characters (P*)
   parm_index                 indn      SF  scroll forward #1 lines (P)
   parm_insert_line           il        AL  insert #1 lines (P*)
   parm_left_cursor           cub       LE  move #1 characters to the left (P)
   parm_right_cursor          cuf       RI  move #1 characters to the right (P*)
   parm_rindex                rin       SR  scroll back #1 lines (P)
   parm_up_cursor             cuu       UP  up #1 lines (P*)
   pkey_key                   pfkey     pk  program function key #1 to type string #2
   pkey_local                 pfloc     pl  program function key #1 to execute string #2
   pkey_xmit                  pfx       px  program function key #1 to transmit string #2
   print_screen               mc0       ps  print contents of screen
   prtr_off                   mc4       pf  turn off printer
   prtr_on                    mc5       po  turn on printer
   repeat_char                rep       rp  repeat char #1 #2 times (P*)
   reset_1string              rs1       r1  reset string
   reset_2string              rs2       r2  reset string
   reset_3string              rs3       r3  reset string
   reset_file                 rf        rf  name of reset file
   restore_cursor             rc        rc  restore cursor to position of last save_cursor
   row_address                vpa       cv  vertical position #1 absolute (P)
   save_cursor                sc        sc  save current cursor position (P)
   scroll_forward             ind       sf  scroll text up (P)
   scroll_reverse             ri        sr  scroll text down (P)
   set_attributes             sgr       sa  define video attributes #1-#9 (PG9)
   set_tab                    hts       st  set a tab in every row, current columns
   set_window                 wind      wi  current window is lines #1-#2 cols #3-#4
   tab                        ht        ta  tab to next 8-space hardware tab stop
   to_status_line             tsl       ts  move to status line, column #1
   underline_char             uc        uc  underline char and move past it
   up_half_line               hu        hu  half a line up
   init_prog                  iprog     iP  path name of program for initialization
   key_a1                     ka1       K1  upper left of keypad
   key_a3                     ka3       K3  upper right of keypad
   key_b2                     kb2       K2  center of keypad
   key_c1                     kc1       K4  lower left of keypad
   key_c3                     kc3       K5  lower right of keypad
   prtr_non                   mc5p      pO  turn on printer for #1 bytes
   char_padding               rmp       rP  like ip but when in insert mode
   acs_chars                  acsc      ac  graphics charset pairs, based on vt100
   plab_norm                  pln       pn  program label #1 to show string #2
   key_btab                   kcbt      kB  back-tab key
   enter_xon_mode             smxon     SX  turn on xon/xoff handshaking
   exit_xon_mode              rmxon     RX  turn off xon/xoff handshaking
   enter_am_mode              smam      SA  turn on automatic margins
   exit_am_mode               rmam      RA  turn off automatic margins
   xon_character              xonc      XN  XON character
   xoff_character             xoffc     XF  XOFF character
   ena_acs                    enacs     eA  enable alternate char set
   label_on                   smln      LO  turn on soft labels
   label_off                  rmln      LF  turn off soft labels
   key_beg                    kbeg      @1  begin key
   key_cancel                 kcan      @2  cancel key
   key_close                  kclo      @3  close key
   key_command                kcmd      @4  command key
   key_copy                   kcpy      @5  copy key
   key_create                 kcrt      @6  create key
   key_end                    kend      @7  end key
   key_enter                  kent      @8  enter/send key
   key_exit                   kext      @9  exit key
   key_find                   kfnd      @0  find key
   key_help                   khlp      %1  help key
   key_mark                   kmrk      %2  mark key
   key_message                kmsg      %3  message key
   key_move                   kmov      %4  move key
   key_next                   knxt      %5  next key
   key_open                   kopn      %6  open key
   key_options                kopt      %7  options key
   key_previous               kprv      %8  previous key
   key_print                  kprt      %9  print key
   key_redo                   krdo      %0  redo key
   key_reference              kref      &1  reference key
   key_refresh                krfr      &2  refresh key
   key_replace                krpl      &3  replace key
   key_restart                krst      &4  restart key
   key_resume                 kres      &5  resume key
   key_save                   ksav      &6  save key
   key_suspend                kspd      &7  suspend key
   key_undo                   kund      &8  undo key
   key_sbeg                   kBEG      &9  shifted begin key
   key_scancel                kCAN      &0  shifted cancel key
   key_scommand               kCMD      *1  shifted command key
   key_scopy                  kCPY      *2  shifted copy key
   key_screate                kCRT      *3  shifted create key
   key_sdc                    kDC       *4  shifted delete-character key
   key_sdl                    kDL       *5  shifted delete-line key
   key_select                 kslt      *6  select key
   key_send                   kEND      *7  shifted end key
   key_seol                   kEOL      *8  shifted clear-to-end-of-line key
   key_sexit                  kEXT      *9  shifted exit key
   key_sfind                  kFND      *0  shifted find key
   key_shelp                  kHLP      #1  shifted help key
   key_shome                  kHOM      #2  shifted home key
   key_sic                    kIC       #3  shifted insert-character key
   key_sleft                  kLFT      #4  shifted left-arrow key
   key_smessage               kMSG      %a  shifted message key
   key_smove                  kMOV      %b  shifted move key
   key_snext                  kNXT      %c  shifted next key
   key_soptions               kOPT      %d  shifted options key
   key_sprevious              kPRV      %e  shifted previous key
   key_sprint                 kPRT      %f  shifted print key
   key_sredo                  kRDO      %g  shifted redo key
   key_sreplace               kRPL      %h  shifted replace key
   key_sright                 kRIT      %i  shifted right-arrow key
   key_srsume                 kRES      %j  shifted resume key
   key_ssave                  kSAV      !1  shifted save key
   key_ssuspend               kSPD      !2  shifted suspend key
   key_sundo                  kUND      !3  shifted undo key
   req_for_input              rfi       RF  send next input char (for ptys)
   key_f11                    kf11      F1  F11 function key
   key_f12                    kf12      F2  F12 function key
   key_f13                    kf13      F3  F13 function key
   key_f14                    kf14      F4  F14 function key
   key_f15                    kf15      F5  F15 function key
   key_f16                    kf16      F6  F16 function key
   key_f17                    kf17      F7  F17 function key
   key_f18                    kf18      F8  F18 function key
   key_f19                    kf19      F9  F19 function key
   key_f20                    kf20      FA  F20 function key
   key_f21                    kf21      FB  F21 function key
   key_f22                    kf22      FC  F22 function key
   key_f23                    kf23      FD  F23 function key
   key_f24                    kf24      FE  F24 function key
   key_f25                    kf25      FF  F25 function key
   key_f26                    kf26      FG  F26 function key
   key_f27                    kf27      FH  F27 function key
   key_f28                    kf28      FI  F28 function key
   key_f29                    kf29      FJ  F29 function key
   key_f30                    kf30      FK  F30 function key
   key_f31                    kf31      FL  F31 function key
   key_f32                    kf32      FM  F32 function key
   key_f33                    kf33      FN  F33 function key
   key_f34                    kf34      FO  F34 function key
   key_f35                    kf35      FP  F35 function key
   key_f36                    kf36      FQ  F36 function key
   key_f37                    kf37      FR  F37 function key
   key_f38                    kf38      FS  F38 function key
   key_f39                    kf39      FT  F39 function key
   key_f40                    kf40      FU  F40 function key
   key_f41                    kf41      FV  F41 function key
   key_f42                    kf42      FW  F42 function key
   key_f43                    kf43      FX  F43 function key
   key_f44                    kf44      FY  F44 function key
   key_f45                    kf45      FZ  F45 function key
   key_f46                    kf46      Fa  F46 function key
   key_f47                    kf47      Fb  F47 function key
   key_f48                    kf48      Fc  F48 function key
   key_f49                    kf49      Fd  F49 function key
   key_f50                    kf50      Fe  F50 function key
   key_f51                    kf51      Ff  F51 function key
   key_f52                    kf52      Fg  F52 function key
   key_f53                    kf53      Fh  F53 function key
   key_f54                    kf54      Fi  F54 function key
   key_f55                    kf55      Fj  F55 function key
   key_f56                    kf56      Fk  F56 function key
   key_f57                    kf57      Fl  F57 function key
   key_f58                    kf58      Fm  F58 function key
   key_f59                    kf59      Fn  F59 function key
   key_f60                    kf60      Fo  F60 function key
   key_f61                    kf61      Fp  F61 function key
   key_f62                    kf62      Fq  F62 function key
   key_f63                    kf63      Fr  F63 function key
   clr_bol                    el1       cb  Clear to beginning of line
   clear_margins              mgc       MC  clear right and left soft margins
   set_left_margin            smgl      ML  set left soft margin at current column (not in BSD termcap)
   set_right_margin           smgr      MR  set right soft margin at current column
   label_format               fln       Lf  label format
   set_clock                  sclk      SC  set clock, #1 hrs #2 mins #3 secs
   display_clock              dclk      DK  display clock
   remove_clock               rmclk     RC  remove clock
   create_window              cwin      CW  define a window #1 from #2,#3 to #4,#5
   goto_window                wingo     WG  go to window #1
   hangup                     hup       HU  hang-up phone
   dial_phone                 dial      DI  dial number #1
   quick_dial                 qdial     QD  dial number #1 without checking
   tone                       tone      TO  select touch tone dialing
   pulse                      pulse     PU  select pulse dialing
   flash_hook                 hook      fh  flash switch hook
   fixed_pause                pause     PA  pause for 2-3 seconds
   wait_tone                  wait      WA  wait for dial-tone
   user0                      u0        u0  User string #0
   user1                      u1        u1  User string #1
   user2                      u2        u2  User string #2
   user3                      u3        u3  User string #3
   user4                      u4        u4  User string #4
   user5                      u5        u5  User string #5
   user6                      u6        u6  User string #6
   user7                      u7        u7  User string #7
   user8                      u8        u8  User string #8
   user9                      u9        u9  User string #9
   orig_pair                  op        op  Set default pair to its original value
   orig_colors                oc        oc  Set all color pairs to the original ones
   initialize_color           initc     Ic  initialize color #1 to (#2,#3,#4)
   initialize_pair            initp     Ip  Initialize color pair #1 to fg=(#2,#3,#4), bg=(#5,#6,#7)
   set_color_pair             scp       sp  Set current color pair to #1
   set_foreground             setf      Sf  Set foreground color #1
   set_background             setb      Sb  Set background color #1
   change_char_pitch          cpi       ZA  Change number of characters per inch to #1
   change_line_pitch          lpi       ZB  Change number of lines per inch to #1
   change_res_horz            chr       ZC  Change horizontal resolution to #1
   change_res_vert            cvr       ZD  Change vertical resolution to #1
   define_char                defc      ZE  Define a character #1, #2 dots wide, descender #3
   enter_doublewide_mode      swidm     ZF  Enter double-wide mode
   enter_draft_quality        sdrfq     ZG  Enter draft-quality mode
   enter_italics_mode         sitm      ZH  Enter italic mode
   enter_leftward_mode        slm       ZI  Start leftward carriage motion
   enter_micro_mode           smicm     ZJ  Start micro-motion mode
   enter_near_letter_quality  snlq      ZK  Enter NLQ mode
   enter_normal_quality       snrmq     ZL  Enter normal-quality mode
   enter_shadow_mode          sshm      ZM  Enter shadow-print mode
   enter_subscript_mode       ssubm     ZN  Enter subscript mode
   enter_superscript_mode     ssupm     ZO  Enter superscript mode
   enter_upward_mode          sum       ZP  Start upward carriage motion
   exit_doublewide_mode       rwidm     ZQ  End double-wide mode
   exit_italics_mode          ritm      ZR  End italic mode
   exit_leftward_mode         rlm       ZS  End left-motion mode
   exit_micro_mode            rmicm     ZT  End micro-motion mode
   exit_shadow_mode           rshm      ZU  End shadow-print mode
   exit_subscript_mode        rsubm     ZV  End subscript mode
   exit_superscript_mode      rsupm     ZW  End superscript mode
   exit_upward_mode           rum       ZX  End reverse character motion
   micro_column_address       mhpa      ZY  Like column_address in micro mode
   micro_down                 mcud1     ZZ  Like cursor_down in micro mode
   micro_left                 mcub1     Za  Like cursor_left in micro mode
   micro_right                mcuf1     Zb  Like cursor_right in micro mode
   micro_row_address          mvpa      Zc  Like row_address #1 in micro mode
   micro_up                   mcuu1     Zd  Like cursor_up in micro mode
   order_of_pins              porder    Ze  Match software bits to print-head pins
   parm_down_micro            mcud      Zf  Like parm_down_cursor in micro mode
   parm_left_micro            mcub      Zg  Like parm_left_cursor in micro mode
   parm_right_micro           mcuf      Zh  Like parm_right_cursor in micro mode
   parm_up_micro              mcuu      Zi  Like parm_up_cursor in micro mode
   select_char_set            scs       Zj  Select character set, #1
   set_bottom_margin          smgb      Zk  Set bottom margin at current line
   set_bottom_margin_parm     smgbp     Zl  Set bottom margin at line #1 or (if smgtp is not given) #2 lines from bottom
   set_left_margin_parm       smglp     Zm  Set left (right) margin at column #1
   set_right_margin_parm      smgrp     Zn  Set right margin at column #1
   set_top_margin             smgt      Zo  Set top margin at current line
   set_top_margin_parm        smgtp     Zp  Set top (bottom) margin at row #1
   start_bit_image            sbim      Zq  Start printing bit image graphics
   start_char_set_def         scsd      Zr  Start character set definition #1, with #2 characters in the set
   stop_bit_image             rbim      Zs  Stop printing bit image graphics
   stop_char_set_def          rcsd      Zt  End definition of character set #1
   subscript_characters       subcs     Zu  List of subscriptable characters
   superscript_characters     supcs     Zv  List of superscriptable characters
   these_cause_cr             docr      Zw  Printing any of these characters causes CR
   zero_motion                zerom     Zx  No motion for subsequent character

   The following string capabilities are present in the SVr4.0 term structure, but were originally not documented in the man page.

                                  Code
   String Capability Name     TI        TC  Description
   ────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────
   char_set_names             csnm      Zy  Produce #1'th item from list of character set names
   key_mouse                  kmous     Km  Mouse event has occurred
   mouse_info                 minfo     Mi  Mouse status information
   req_mouse_pos              reqmp     RQ  Request mouse position
   get_mouse                  getm      Gm  Curses should get button events, parameter #1 not documented.
   set_a_foreground           setaf     AF  Set foreground color to #1, using ANSI escape
   set_a_background           setab     AB  Set background color to #1, using ANSI escape
   pkey_plab                  pfxl      xl  Program function key #1 to type string #2 and show string #3
   device_type                devt      dv  Indicate language, codeset support
   code_set_init              csin      ci  Init sequence for multiple codesets
   set0_des_seq               s0ds      s0  Shift to codeset 0 (EUC set 0, ASCII)
   set1_des_seq               s1ds      s1  Shift to codeset 1
   set2_des_seq               s2ds      s2  Shift to codeset 2
   set3_des_seq               s3ds      s3  Shift to codeset 3
   set_lr_margin              smglr     ML  Set both left and right margins to #1, #2.  (ML is not in BSD termcap).
   set_tb_margin              smgtb     MT  Sets both top and bottom margins to #1, #2
   bit_image_repeat           birep     Xy  Repeat bit image cell #1 #2 times
   bit_image_newline          binel     Zz  Move to next row of the bit image
   bit_image_carriage_return  bicr      Yv  Move to beginning of same row
   color_names                colornm   Yw  Give name for color #1
   define_bit_image_region    defbi     Yx  Define rectangular bit image region
   end_bit_image_region       endbi     Yy  End a bit-image region
   set_color_band             setcolor  Yz  Change to ribbon color #1
   set_page_length            slines    YZ  Set page length to #1 lines
   display_pc_char            dispc     S1  Display PC character #1
   enter_pc_charset_mode      smpch     S2  Enter PC character display mode
   exit_pc_charset_mode       rmpch     S3  Exit PC character display mode
   enter_scancode_mode        smsc      S4  Enter PC scancode mode
   exit_scancode_mode         rmsc      S5  Exit PC scancode mode
   pc_term_options            pctrm     S6  PC terminal options
   scancode_escape            scesc     S7  Escape for scancode emulation
   alt_scancode_esc           scesa     S8  Alternate escape for scancode emulation

   The XSI Curses standard added these hardcopy capabilities.  They were used in some post-4.1 versions of System V curses, e.g., Solaris 2.5 and IRIX 6.x.  Except for  YI,  the  ncurses
   termcap names for them are invented.  According to the XSI Curses standard, they have no termcap names.  If your compiled terminfo entries use these, they may not be binary-compatible
   with System V terminfo entries after SVr4.1; beware!

                                  Code
   String Capability Name     TI        TC  Description
   
   enter_horizontal_hl_mode   ehhlm     Xh  Enter horizontal highlight mode
   enter_left_hl_mode         elhlm     Xl  Enter left highlight mode
   enter_low_hl_mode          elohlm    Xo  Enter low highlight mode
   enter_right_hl_mode        erhlm     Xr  Enter right highlight mode
   enter_top_hl_mode          ethlm     Xt  Enter top highlight mode
   enter_vertical_hl_mode     evhlm     Xv  Enter vertical highlight mode
   set_a_attributes           sgr1      sA  Define second set of video attributes #1-#6
   set_pglen_inch             slength   YI  Set page length to #1 hundredth of an inch (some implementations use sL for termcap).

User-Defined Capabilities

   The  preceding  section listed the predefined capabilities.  They deal with some special features for terminals no longer (or possibly never) produced.  Occasionally there are special
   features of newer terminals which are awkward or impossible to represent by reusing the predefined capabilities.

   ncurses addresses this limitation by allowing user-defined capabilities.  The tic and infocmp programs provide the -x option for this purpose.  When -x is set, tic treats unknown  ca
   pabilities  as user-defined.  That is, if tic encounters a capability name which it does not recognize, it infers its type (Boolean, number or string) from the syntax and makes an ex
   tended table entry for that capability.  The use_extended_names(3NCURSES) function makes this information conditionally available to applications.  The ncurses  library  provides  the
   data leaving most of the behavior to applications:

      User-defined capability strings whose name begins with k are treated as function keys.

      The types (Boolean, number, string) determined by tic can be inferred by successful calls on tigetflag, etc.

      If the capability name happens to be two characters, the capability is also available through the termcap interface.

   While  termcap  is  said to be extensible because it does not use a predefined set of capabilities, in practice it has been limited to the capabilities defined by terminfo implementa
   tions.  As a rule, user-defined capabilities intended for use by termcap applications should be limited to Booleans and numbers to avoid running past the 1023 byte  limit  assumed  by
   termcap implementations and their applications.  In particular, providing extended sets of function keys (past the 60 numbered keys and the handful of special named keys) is best done
   using the longer names available using terminfo.

   The ncurses library uses a few of these user-defined capabilities, as described in user_caps(5).  Other user-defined capabilities (including function keys) are described in the termi
   nal database, in the section on NCURSES USER-DEFINABLE CAPABILITIES

A Sample Entry

   The following entry, describing an ANSI-standard terminal, is representative of what a terminfo entry for a modern terminal typically looks like.

   ansi|ansi/pc-term compatible with color,
           am, mc5i, mir, msgr,
           colors#8, cols#80, it#8, lines#24, ncv#3, pairs#64,
           acsc=+\020\,\021-\030.^Y0\333`\004a\261f\370g\361h\260
                j\331k\277l\332m\300n\305o~p\304q\304r\304s_t\303
                u\264v\301w\302x\263y\363z\362{\343|\330}\234~\376,
           bel=^G, blink=\E[5m, bold=\E[1m, cbt=\E[Z, clear=\E[H\E[J,
           cr=^M, cub=\E[%p1%dD, cub1=\E[D, cud=\E[%p1%dB, cud1=\E[B,
           cuf=\E[%p1%dC, cuf1=\E[C, cup=\E[%i%p1%d;%p2%dH,
           cuu=\E[%p1%dA, cuu1=\E[A, dch=\E[%p1%dP, dch1=\E[P,
           dl=\E[%p1%dM, dl1=\E[M, ech=\E[%p1%dX, ed=\E[J, el=\E[K,
           el1=\E[1K, home=\E[H, hpa=\E[%i%p1%dG, ht=\E[I, hts=\EH,
           ich=\E[%p1%d@, il=\E[%p1%dL, il1=\E[L, ind=^J,
           indn=\E[%p1%dS, invis=\E[8m, kbs=^H, kcbt=\E[Z, kcub1=\E[D,
           kcud1=\E[B, kcuf1=\E[C, kcuu1=\E[A, khome=\E[H, kich1=\E[L,
           mc4=\E[4i, mc5=\E[5i, nel=\r\E[S, op=\E[39;49m,
           rep=%p1%c\E[%p2%{1}%-%db, rev=\E[7m, rin=\E[%p1%dT,
           rmacs=\E[10m, rmpch=\E[10m, rmso=\E[m, rmul=\E[m,
           s0ds=\E(B, s1ds=\E)B, s2ds=\E*B, s3ds=\E+B,
           setab=\E[4%p1%dm, setaf=\E[3%p1%dm,
           sgr=\E[0;10%?%p1%t;7%;
                      %?%p2%t;4%;
                      %?%p3%t;7%;
                      %?%p4%t;5%;
                      %?%p6%t;1%;
                      %?%p7%t;8%;
                      %?%p9%t;11%;m,
           sgr0=\E[0;10m, smacs=\E[11m, smpch=\E[11m, smso=\E[7m,
           smul=\E[4m, tbc=\E[3g, u6=\E[%i%d;%dR, u7=\E[6n,
           u8=\E[?%[;0123456789]c, u9=\E[c, vpa=\E[%i%p1%dd,

   Entries may continue onto multiple lines by placing white space at the beginning of each line except the first.  Comments may be included on lines beginning with #”.  Capabilities in
   terminfo are of three types:

      Boolean capabilities which indicate that the terminal has some particular feature,

      numeric capabilities giving the size of the terminal or the size of particular delays, and

      string capabilities, which give a sequence which can be used to perform particular terminal operations.

Types of Capabilities

   All capabilities have names.  For instance, the fact that ANSI-standard terminals have automatic margins (i.e., an automatic return and line-feed when the end of a line is reached) is
   indicated  by the capability am.  Hence the description of ansi includes am.  Numeric capabilities are followed by the character #” and then a positive value.  Thus cols, which indi‐
   cates the number of columns the terminal has, gives the value 80 for ansi.  Values for numeric capabilities may be specified in decimal, octal, or hexadecimal, using the C  program
   ming language conventions (e.g., 255, 0377 and 0xff or 0xFF).

   Finally, string valued capabilities, such as el (clear to end of line sequence) are given by the two-character code, an =, and then a string ending at the next following ,.

   A number of escape sequences are provided in the string valued capabilities for easy encoding of characters there:

      Both \E and \e map to an ESCAPE character,

      ^x maps to a control-x for any appropriate x, and

      the sequences

         \n, \l, \r, \t, \b, \f, and \s

       produce

         newline, line-feed, return, tab, backspace, form-feed, and space,

       respectively.

   X/Open  Curses does not say what appropriate x might be.  In practice, that is a printable ASCII graphic character.  The special case ^?” is interpreted as DEL (127).  In all other
   cases, the character value is logically and-ed with 0x1f, mapping to ASCII control codes in the range 0 through 31.

   Other escapes include

      \^ for ^,

      \\ for \,

      \, for comma,

      \: for :,

      and \0 for null.

       \0 will produce \200, which does not terminate a string but behaves as a null character on most terminals, providing CS7 is specified.  See stty(1).

       The reason for this quirk is to maintain binary compatibility of the compiled terminfo files with other implementations, e.g., the SVr4 systems,  which  document  this.   Compiled
       terminfo files use null-terminated strings, with no lengths.  Modifying this would require a new binary format, which would not work with other implementations.

   Finally, characters may be given as three octal digits after a \.

   A  delay  in  milliseconds  may appear anywhere in a string capability, enclosed in $<..> brackets, as in el=\EK$<5>, and padding characters are supplied by tputs(3NCURSES) to provide
   this delay.

      The delay must be a number with at most one decimal place of precision; it may be followed by suffixes * or / or both.

      A * indicates that the padding required is proportional to the number of lines affected by the operation, and the amount given is the per-affected-unit  padding  required.   (In
       the case of insert character, the factor is still the number of lines affected.)

       Normally, padding is advisory if the device has the xon capability; it is used for cost computation but does not trigger delays.

      A / suffix indicates that the padding is mandatory and forces a delay of the given number of milliseconds even on devices for which xon is present to indicate flow control.

   Sometimes individual capabilities must be commented out.  To do this, put a period before the capability name.  For example, see the second ind in the example above.

Fetching Compiled Descriptions

   Terminal descriptions in ncurses are stored in terminal databases.  These databases, which are found by their pathname, may be configured either as directory trees or hashed databases
   (see term(5)),

   The  library uses a compiled-in list of pathnames, which can be overridden by environment variables.  Before starting to search, ncurses checks the search list, eliminating duplicates
   and pathnames where no terminal database is found.  The ncurses library reads the first description which passes its consistency checks.

      The environment variable TERMINFO is checked first, for a terminal database containing the terminal description.

      Next, ncurses looks in $HOME/.terminfo for a compiled description.

       This is an optional feature which may be omitted entirely from the library, or limited to prevent accidental use by privileged applications.

      Next, if the environment variable TERMINFO_DIRS is set, ncurses interprets the contents of that variable as a list  of  colon-separated  pathnames  of  terminal  databases  to  be
       searched.

       An empty pathname (i.e., if the variable begins or ends with a colon, or contains adjacent colons) is interpreted as the system location /etc/terminfo.

      Finally, ncurses searches these compiled-in locations:

          a list of directories (/etc/terminfo:/lib/terminfo:/usr/share/terminfo), and

          the system terminfo directory, /etc/terminfo

   The  TERMINFO  variable can contain a terminal description instead of the pathname of a terminal database.  If this variable begins with hex: or b64: then ncurses reads a terminal
   description from hexadecimal- or base64-encoded data, and if that description matches the name sought, will use that.  This encoded data can be set using the -Q option of tic or in
   focmp.

   The preceding addresses the usual configuration of ncurses, which uses terminal descriptions prepared in terminfo format.  While termcap is less expressive, ncurses can also  be  con
   figured  to read termcap descriptions.  In that configuration, it checks the TERMCAP and TERMPATH variables (for content and search path, respectively) after the system terminal data
   base.

Preparing Descriptions

   We now outline how to prepare descriptions of terminals.  The most effective way to prepare a terminal description is by imitating the description of a similar  terminal  in  terminfo
   and  to build up a description gradually, using partial descriptions with vi or some other screen-oriented program to check that they are correct.  Be aware that a very unusual termi
   nal may expose deficiencies in the ability of the terminfo file to describe it or bugs in the screen-handling code of the test program.

   To get the padding for insert line right (if the terminal manufacturer did not document it) a severe test is to edit a large file at 9600 baud, delete 16 or so lines from  the  middle
   of the screen, then hit the u key several times quickly.  If the terminal messes up, more padding is usually needed.  A similar test can be used for insert character.

Basic Capabilities

   The  number  of  columns on each line for the terminal is given by the cols numeric capability.  If the terminal is a CRT, then the number of lines on the screen is given by the lines
   capability.  If the terminal wraps around to the beginning of the next line when it reaches the right margin, then it should have the am capability.  If the  terminal  can  clear  its
   screen,  leaving  the cursor in the home position, then this is given by the clear string capability.  If the terminal overstrikes (rather than clearing a position when a character is
   struck over) then it should have the os capability.  If the terminal is a printing terminal, with no soft copy unit, give it both hc and os.  (os applies to storage  scope  terminals,
   such  as  TEKTRONIX 4010 series, as well as hard copy and APL terminals.)  If there is a code to move the cursor to the left edge of the current line, give this as cr.  (Normally this
   will be carriage return, control/M.)  If there is a code to produce an audible signal (bell, beep, etc) give this as bel.

   If there is a code to move the cursor one position to the left (such as backspace) that capability should be given as cub1.  Similarly, codes to move to the right, up, and down should
   be given as cuf1, cuu1, and cud1.  These local cursor motions should not alter the text they pass over, for example, you would not normally use cuf1=  because the space would  erase
   the character moved over.

   A very important point here is that the local cursor motions encoded in terminfo are undefined at the left and top edges of a CRT terminal.  Programs should never attempt to backspace
   around  the  left  edge, unless bw is given, and never attempt to go up locally off the top.  In order to scroll text up, a program will go to the bottom left corner of the screen and
   send the ind (index) string.

   To scroll text down, a program goes to the top left corner of the screen and sends the ri (reverse index) string.  The strings ind and ri are undefined when not  on  their  respective
   corners of the screen.

   Parameterized  versions  of the scrolling sequences are indn and rin which have the same semantics as ind and ri except that they take one parameter, and scroll that many lines.  They
   are also undefined except at the appropriate edge of the screen.

   The am capability tells whether the cursor sticks at the right edge of the screen when text is output, but this does not necessarily apply to a cuf1 from the last  column.   The  only
   local motion which is defined from the left edge is if bw is given, then a cub1 from the left edge will move to the right edge of the previous line.  If bw is not given, the effect is
   undefined.   This  is  useful for drawing a box around the edge of the screen, for example.  If the terminal has switch selectable automatic margins, the terminfo file usually assumes
   that this is on; i.e., am.  If the terminal has a command which moves to the first column of the next line, that command can be given as nel (newline).  It does not matter if the com
   mand clears the remainder of the current line, so if the terminal has no cr and lf it may still be possible to craft a working nel out of one or both of them.

   These capabilities suffice to describe hard-copy and glass-tty terminals.  Thus the model 33 teletype is described as

   33|tty33|tty|model 33 teletype,
           bel=^G, cols#72, cr=^M, cud1=^J, hc, ind=^J, os,

   while the Lear Siegler ADM-3 is described as

   adm3|3|lsi adm3,
           am, bel=^G, clear=^Z, cols#80, cr=^M, cub1=^H, cud1=^J,
           ind=^J, lines#24,

Parameterized Strings

   Cursor addressing and other strings requiring parameters in the terminal are described by a parameterized string capability, with printf-like escapes such as %x in it.   For  example,
   to  address  the  cursor,  the  cup  capability is given, using two parameters: the line and column to address to.  (Lines and columns are numbered from zero and refer to the physical
   screen visible to the user, not to any unseen memory.)  If the terminal has memory relative cursor addressing, that can be indicated by mrcup.

   The parameter mechanism uses a stack and special % codes to manipulate it.  Typically a sequence will push one of the parameters onto the stack and  then  print  it  in  some  format.
   Print  (e.g.,  %d) is a special case.  Other operations, including %t pop their operand from the stack.  It is noted that more complex operations are often necessary, e.g., in the
   sgr string.

   The % encodings have the following meanings:

   %%   outputs %

   %[[:]flags][width[.precision]][doxXs]
        as in printf(3), flags are [-+#] and space.  Use a “:” to allow the next character to be a “-” flag, avoiding interpreting “%-” as an operator.

   %c   print pop() like %c in printf

   %s   print pop() like %s in printf

   %p[1-9]
        push i'th parameter

   %P[a-z]
        set dynamic variable [a-z] to pop()

   %g[a-z]
        get dynamic variable [a-z] and push it

   %P[A-Z]
        set static variable [a-z] to pop()

   %g[A-Z]
        get static variable [a-z] and push it

        The terms “static” and “dynamic” are misleading.  Historically, these are simply two different sets of variables, whose values are not reset  between  calls  to  tparm(3NCURSES).
        However, that fact is not documented in other implementations.  Relying on it will adversely impact portability to other implementations:

        •   SVr2  curses  supported  dynamic variables.  Those are set only by a %P operator.  A %g for a given variable without first setting it with %P will give unpredictable results,
            because dynamic variables are an uninitialized local array on the stack in the tparm function.

        •   SVr3.2 curses supported static variables.  Those are an array in the TERMINAL structure (declared in term.h), and are zeroed automatically when the setupterm  function  allo‐
            cates the data.

        •   SVr4 curses made no further improvements to the dynamic/static variable feature.

        •   Solaris XPG4 curses does not distinguish between dynamic and static variables.  They are the same.  Like SVr4 curses, XPG4 curses does not initialize these explicitly.

        •   Before version 6.3, ncurses stores both dynamic and static variables in persistent storage, initialized to zeros.

        •   Beginning with version 6.3, ncurses stores static and dynamic variables in the same manner as SVr4.

            •   Unlike other implementations, ncurses zeros dynamic variables before the first %g or %P operator.

            •   Like SVr2, the scope of dynamic variables in ncurses is within the current call to tparm.  Use static variables if persistent storage is needed.

   %'c' char constant c

   %{nn}
        integer constant nn

   %l   push strlen(pop)

   %+, %-, %*, %/, %m
        arithmetic (%m is mod): push(pop() op pop())

   %&, %|, %^
        bit operations (“and”, “or” and exclusive “or”): push(pop() op pop())

   %=, %>, %<
        logical operations: push(pop() op pop())

   %A, %O
        logical “and” and “or” operations (for conditionals)

   %!, %~
        unary operations (logical and bit complement): push(op pop())

   %i   add 1 to first two parameters (for ANSI terminals)

   %? expr %t thenpart %e elsepart %;
        This forms an if-then-else.  The %e elsepart is optional.  Usually the %? expr part pushes a value onto the stack, and %t pops it from the stack, testing if it is nonzero (true).
        If it is zero (false), control passes to the %e (else) part.

        It is possible to form else-if's a la Algol 68:
        %? c1 %t b1 %e c2 %t b2 %e c3 %t b3 %e c4 %t b4 %e %;

        where ci are conditions, bi are bodies.

        Use  the  -f option of tic or infocmp to see the structure of if-then-else's.  Some strings, e.g., sgr can be very complicated when written on one line.  The -f option splits the
        string into lines with the parts indented.

   Binary operations are in postfix form with the operands in the usual order.  That is, to get x-5 one would use “%gx%{5}%-”.  %P and %g variables are  persistent  across  escape-string
   evaluations.

   Consider  the HP2645, which, to get to line 3 and column 12, needs to be sent \E&a12c03Y padded for 6 milliseconds.  The order of the lines and columns is inverted here, and the lines
   and column are printed as two digits.  The corresponding terminal description is expressed thus:
          cup=\E&a%p2%dc%p1%dY$<6>,

   The Microterm ACT-IV needs the current line and column sent preceded by a ^T, with the line and column simply encoded in binary,
          cup=^T%p1%c%p2%c

   Terminals which use “%c” need to be able to backspace the cursor (cub1), and to move the cursor up one line on the screen (cuu1).  This is necessary because it is not always  safe  to
   transmit  \n  ^D  and  \r, as the system may change or discard them.  (The library routines dealing with terminfo set tty modes so that tabs are never expanded, so \t is safe to send.
   This turns out to be essential for the Ann Arbor 4080.)

   A final example is the LSI ADM-3A, which uses line and column offset by a space, thus
          cup=\E=%p1%' '%+%c%p2%' '%+%c

   After sending \E=, this pushes the first parameter, pushes the ASCII value for a space (32), adds them (pushing the sum on the stack in place of the two previous values) and outputs
   that value as a character.  Then the same is done for the second parameter.  More complex arithmetic is possible using the stack.

Cursor Motions

   If the terminal has a fast way to home the cursor (to very upper left corner of screen) then this can be given as home; similarly a fast way of getting to the lower  left-hand  corner
   can  be given as ll; this may involve going up with cuu1 from the home position, but a program should never do this itself (unless ll does) because it can make no assumption about the
   effect of moving up from the home position.  Note that the home position is the same as addressing to (0,0): to the top left corner of the screen, not of memory.  (Thus, the  \EH  se
   quence on HP terminals cannot be used for home.)

   If  the  terminal  has line or column absolute cursor addressing, these can be given as single parameter capabilities hpa (horizontal position absolute) and vpa (vertical position ab
   solute).  Sometimes these are shorter than the more general two parameter sequence (as with the hp2645) and can be used in preference to cup.  If there are parameterized local motions
   (e.g., move n spaces to the right) these can be given as cud, cub, cuf, and cuu with a single parameter indicating how many spaces to move.  These are primarily useful if the terminal
   does not have cup, such as the TEKTRONIX 4025.

   If the terminal needs to be in a special mode when running a program that uses these capabilities, the codes to enter and exit this mode can be given as smcup and rmcup.  This arises,
   for example, from terminals like the Concept with more than one page of memory.  If the terminal has only memory relative cursor addressing and not screen relative cursor  addressing,
   a  one screen-sized window must be fixed into the terminal for cursor addressing to work properly.  This is also used for the TEKTRONIX 4025, where smcup sets the command character to
   be the one used by terminfo.  If the smcup sequence will not restore the screen after an rmcup sequence is output (to the state prior to outputting rmcup), specify nrrmc.

Margins

   SVr4 (and X/Open Curses) list several string capabilities for setting margins.  Two were intended for use with terminals, and another six were intended for use with printers.

      The two terminal capabilities assume that the terminal may have the capability of setting the left and/or right margin at the current cursor column position.

      The printer capabilities assume that the printer may have two types of capability:

          the ability to set a top and/or bottom margin using the current line position, and

          parameterized capabilities for setting the top, bottom, left, right margins given the number of lines or columns.

   In practice, the categorization into terminal and printer is not suitable:

      The AT&T SVr4 terminal database uses smgl four times, for AT&T hardware.

       Three of the four are printers.  They lack the ability to set left/right margins by specifying the column.

      Other (non-AT&T) terminals may support margins but using different assumptions from AT&T.

       For instance, the DEC VT420 supports left/right margins, but only using a column parameter.  As an added complication, the VT420 uses two settings to fully enable left/right  mar
       gins  (left/right  margin mode, and origin mode).  The former enables the margins, which causes printed text to wrap within margins, but the latter is needed to prevent cursor-ad
       dressing outside those margins.

      Both DEC VT420 left/right margins are set with a single control sequence.  If either is omitted, the corresponding margin is set to the left or right edge of the  display  (rather
       than leaving the margin unmodified).

   These are the margin-related capabilities:

                                                                     Name    Description
                                                                     
                                                                     smgl    Set left margin at current column
                                                                     smgr    Set right margin at current column
                                                                     smgb    Set bottom margin at current line
                                                                     smgt    Set top margin at current line
                                                                     smgbp   Set bottom margin at line N
                                                                     smglp   Set left margin at column N
                                                                     smgrp   Set right margin at column N
                                                                     smgtp   Set top margin at line N
                                                                     smglr   Set both left and right margins to L and R
                                                                     smgtb   Set both top and bottom margins to T and B

   When writing an application that uses these string capabilities, the pairs should be first checked to see if each capability in the pair is set or only one is set:

      If both smglp and smgrp are set, each is used with a single argument, N, that gives the column number of the left and right margin, respectively.

      If both smgtp and smgbp are set, each is used to set the top and bottom margin, respectively:

          smgtp is used with a single argument, N, the line number of the top margin.

          smgbp is used with two arguments, N and M, that give the line number of the bottom margin, the first counting from the top of the page and the second counting from the bottom.
           This accommodates the two styles of specifying the bottom margin in different manufacturers' printers.

       When  designing  a  terminfo entry for a printer that has a settable bottom margin, only the first or second argument should be used, depending on the printer.  When developing an
       application that uses smgbp to set the bottom margin, both arguments must be given.

   Conversely, when only one capability in the pair is set:

      If only one of smglp and smgrp is set, then it is used with two arguments, the column number of the left and right margins, in that order.

      Likewise, if only one of smgtp and smgbp is set, then it is used with two arguments that give the top and bottom margins, in that order, counting from the top of the page.

       When designing a terminfo entry for a printer that requires setting both left and right or top and bottom margins simultaneously, only one capability in the pairs smglp and  smgrp
       or smgtp and smgbp should be defined, leaving the other unset.

   Except  for very old terminal descriptions, e.g., those developed for SVr4, the scheme just described should be considered obsolete.  An improved set of capabilities was added late in
   the SVr4 releases (smglr and smgtb), which explicitly use two parameters for setting the left/right or top/bottom margins.

   When setting margins, the line- and column-values are zero-based.

   The mgc string capability should be defined.  Applications such as tabs(1) rely upon this to reset all margins.

Area Clears

   If the terminal can clear from the current position to the end of the line, leaving the cursor where it is, this should be given as el.  If the terminal can clear from  the  beginning
   of the line to the current position inclusive, leaving the cursor where it is, this should be given as el1.  If the terminal can clear from the current position to the end of the dis
   play, then this should be given as ed.  Ed is only defined from the first column of a line.  (Thus, it can be simulated by a request to delete a large number of lines, if a true ed is
   not available.)

Insert/Delete Line and Vertical Motions

   If  the terminal can open a new blank line before the line where the cursor is, this should be given as il1; this is done only from the first position of a line.  The cursor must then
   appear on the newly blank line.  If the terminal can delete the line which the cursor is on, then this should be given as dl1; this is done only from the first position on the line to
   be deleted.  Versions of il1 and dl1 which take a single parameter and insert or delete that many lines can be given as il and dl.

   If the terminal has a settable scrolling region (like the vt100) the command to set this can be described with the csr capability, which takes two parameters: the top and bottom lines
   of the scrolling region.  The cursor position is, alas, undefined after using this command.

   It is possible to get the effect of insert or delete line using csr on a properly chosen region; the sc and rc (save and restore cursor) commands may be useful for ensuring that  your
   synthesized  insert/delete  string does not move the cursor.  (Note that the ncurses(3NCURSES) library does this synthesis automatically, so you need not compose insert/delete strings
   for an entry with csr).

   Yet another way to construct insert and delete might be to use a combination of index with the memory-lock feature found on some terminals (like the HP-700/90  series,  which  however
   also has insert/delete).

   Inserting  lines  at  the  top or bottom of the screen can also be done using ri or ind on many terminals without a true insert/delete line, and is often faster even on terminals with
   those features.

   The Boolean non_dest_scroll_region should be set if each scrolling window is effectively a view port on a screen-sized canvas.  To test for this capability, create a scrolling  region
   in  the  middle  of the screen, write something to the bottom line, move the cursor to the top of the region, and do ri followed by dl1 or ind.  If the data scrolled off the bottom of
   the region by the ri re-appears, then scrolling is non-destructive.  System V and X/Open Curses expect that ind, ri, indn, and rin will simulate destructive scrolling; their  documen
   tation cautions you not to define csr unless this is true.  This curses implementation is more liberal and will do explicit erases after scrolling if ndsrc is defined.

   If  the  terminal  has  the  ability to define a window as part of memory, which all commands affect, it should be given as the parameterized string wind.  The four parameters are the
   starting and ending lines in memory and the starting and ending columns in memory, in that order.

   If the terminal can retain display memory above, then the da capability should be given; if display memory can be retained below, then db should be given.  These indicate that  delet
   ing a line or scrolling may bring non-blank lines up from below or that scrolling back with ri may bring down non-blank lines.

Insert/Delete Character

   There  are  two basic kinds of intelligent terminals with respect to insert/delete character which can be described using terminfo.  The most common insert/delete character operations
   affect only the characters on the current line and shift characters off the end of the line rigidly.  Other terminals, such as the Concept 100 and the Perkin Elmer Owl,  make  a  dis
   tinction  between  typed  and untyped blanks on the screen, shifting upon an insert or delete only to an untyped blank on the screen which is either eliminated, or expanded to two un
   typed blanks.

   You can determine the kind of terminal you have by clearing the screen and then typing text separated by cursor motions.  Type abc    def using local cursor motions (not spaces) be
   tween the abc and the def.  Then position the cursor before the abc and put the terminal in insert mode.  If typing characters causes the rest of the line to shift  rigidly  and
   characters  to  fall  off the end, then your terminal does not distinguish between blanks and untyped positions.  If the abc shifts over to the def which then move together around
   the end of the current line and onto the next as you insert, you have the second type of terminal, and should give the capability in, which stands for insert null.

   While these are two logically separate attributes (one line versus multi-line insert mode, and special treatment of untyped spaces) we have seen no terminals whose insert mode  cannot
   be described with the single attribute.

   Terminfo  can describe both terminals which have an insert mode, and terminals which send a simple sequence to open a blank position on the current line.  Give as smir the sequence to
   get into insert mode.  Give as rmir the sequence to leave insert mode.  Now give as ich1 any sequence needed to be sent just before sending the character to be inserted.  Most  termi
   nals with a true insert mode will not give ich1; terminals which send a sequence to open a screen position should give it here.

   If your terminal has both, insert mode is usually preferable to ich1.  Technically, you should not give both unless the terminal actually requires both to be used in combination.  Ac
   cordingly,  some  non-curses  applications  get  confused if both are present; the symptom is doubled characters in an update using insert.  This requirement is now rare; most ich se
   quences do not require previous smir, and most smir insert modes do not require ich1 before each character.  Therefore, the new curses actually assumes this is the case and  uses  ei
   ther  rmir/smir or ich/ich1 as appropriate (but not both).  If you have to write an entry to be used under new curses for a terminal old enough to need both, include the rmir/smir se
   quences in ich1.

   If post insert padding is needed, give this as a number of milliseconds in ip (a string option).  Any other sequence which may need to be sent after an insert of  a  single  character
   may  also  be  given  in ip.  If your terminal needs both to be placed into an insert mode and a special code to precede each inserted character, then both smir/rmir and ich1 can be
   given, and both will be used.  The ich capability, with one parameter, n, will repeat the effects of ich1 n times.

   If padding is necessary between characters typed while not in insert mode, give this as a number of milliseconds padding in rmp.

   It is occasionally necessary to move around while in insert mode to delete characters on the same line (e.g., if there is a tab after the insertion position).  If your terminal allows
   motion while in insert mode you can give the capability mir to speed up inserting in this case.  Omitting mir will affect only speed.  Some terminals (notably  Datamedia's)  must  not
   have mir because of the way their insert mode works.

   Finally,  you  can  specify  dch1 to delete a single character, dch with one parameter, n, to delete ncharacters, and delete mode by giving smdc and rmdc to enter and exit delete mode
   (any mode the terminal needs to be placed in for dch1 to work).

   A command to erase n characters (equivalent to outputting n blanks without moving the cursor) can be given as ech with one parameter.

Highlighting, Underlining, and Visible Bells

   If your terminal has one or more kinds of display attributes, these can be represented in a number of different ways.  You should choose one display form as standout mode,  represent
   ing a good, high contrast, easy-on-the-eyes, format for highlighting error messages and other attention getters.  (If you have a choice, reverse video plus half-bright is good, or re
   verse video alone.)  The sequences to enter and exit standout mode are given as smso and rmso, respectively.  If the code to change into or out of standout mode leaves one or even two
   blank spaces on the screen, as the TVI 912 and Teleray 1061 do, then xmc should be given to tell how many spaces are left.

   Codes to begin underlining and end underlining can be given as smul and rmul respectively.  If the terminal has a code to underline the current character and move the cursor one space
   to the right, such as the Microterm Mime, this can be given as uc.

   Other  capabilities  to  enter  various  highlighting modes include blink (blinking) bold (bold or extra bright) dim (dim or half-bright) invis (blanking or invisible text) prot (pro
   tected) rev (reverse video) sgr0 (turn off all attribute modes) smacs (enter alternate character set mode) and rmacs (exit alternate character set mode).   Turning  on  any  of  these
   modes singly may or may not turn off other modes.

   If there is a sequence to set arbitrary combinations of modes, this should be given as sgr (set attributes), taking 9 parameters.  Each parameter is either zero (0) or nonzero, as the
   corresponding  attribute is on or off.  The 9 parameters are, in order: standout, underline, reverse, blink, dim, bold, blank, protect, alternate character set.  Not all modes need be
   supported by sgr, only those for which corresponding separate attribute commands exist.

   For example, the DEC vt220 supports most of the modes:

                                                                       tparm Parameter   Attribute    Escape Sequence
                                                                       
                                                                       none              none         \E[0m
                                                                       p1                standout     \E[0;1;7m
                                                                       p2                underline    \E[0;4m
                                                                       p3                reverse      \E[0;7m
                                                                       p4                blink        \E[0;5m
                                                                       p5                dim          not available
                                                                       p6                bold         \E[0;1m
                                                                       p7                invis        \E[0;8m
                                                                       p8                protect      not used
                                                                       p9                altcharset   ^O (off) ^N (on)

   We begin each escape sequence by turning off any existing modes, since there is no quick way to determine whether they are active.  Standout is set up to be the combination of reverse
   and bold.  The vt220 terminal has a protect mode, though it is not commonly used in sgr because it protects characters on the screen from the host's  erasures.   The  altcharset  mode
   also is different in that it is either ^O or ^N, depending on whether it is off or on.  If all modes are turned on, the resulting sequence is \E[0;1;4;5;7;8m^N.

   Some sequences are common to different modes.  For example, ;7 is output when either p1 or p3 is true, that is, if either standout or reverse modes are turned on.

   Writing out the above sequences, along with their dependencies yields

                                                                     Sequence   When to Output      terminfo Translation
                                                                     
                                                                     \E[0       always              \E[0
                                                                     ;1         if p1 or p6         %?%p1%p6%|%t;1%;
                                                                     ;4         if p2               %?%p2%|%t;4%;
                                                                     ;5         if p4               %?%p4%|%t;5%;
                                                                     ;7         if p1 or p3         %?%p1%p3%|%t;7%;
                                                                     ;8         if p7               %?%p7%|%t;8%;
                                                                     m          always              m
                                                                     ^N or ^O   if p9 ^N, else ^O   %?%p9%t^N%e^O%;

   Putting this all together into the sgr sequence gives:

       sgr=\E[0%?%p1%p6%|%t;1%;%?%p2%t;4%;%?%p4%t;5%;
           %?%p1%p3%|%t;7%;%?%p7%t;8%;m%?%p9%t\016%e\017%;,

   Remember  that if you specify sgr, you must also specify sgr0.  Also, some implementations rely on sgr being given if sgr0 is, Not all terminfo entries necessarily have an sgr string,
   however.  Many terminfo entries are derived from termcap entries which have no sgr string.  The only drawback to adding an sgr string is that termcap also assumes that sgr0  does  not
   exit alternate character set mode.

   Terminals with the magic cookie glitch (xmc) deposit special cookies when they receive mode-setting sequences, which affect the display algorithm rather than having extra bits for
   each  character.   Some terminals, such as the HP 2621, automatically leave standout mode when they move to a new line or the cursor is addressed.  Programs using standout mode should
   exit standout mode before moving the cursor or sending a newline, unless the msgr capability, asserting that it is safe to move in standout mode, is present.

   If the terminal has a way of flashing the screen to indicate an error quietly (a bell replacement) then this can be given as flash; it must not move the cursor.

   If the cursor needs to be made more visible than normal when it is not on the bottom line (to make, for example, a non-blinking underline into an easier to find block or blinking  un
   derline) give this sequence as cvvis.  If there is a way to make the cursor completely invisible, give that as civis.  The capability cnorm should be given which undoes the effects of
   both of these modes.

   If  your  terminal correctly generates underlined characters (with no special codes needed) even though it does not overstrike, then you should give the capability ul.  If a character
   overstriking another leaves both characters on the screen, specify the capability os.  If overstrikes are erasable with a blank, then this should be indicated by giving eo.

Keypad and Function Keys

   If the terminal has a keypad that transmits codes when the keys are pressed, this information can be given.  Note that it is not possible to handle terminals  where  the  keypad  only
   works  in  local  (this  applies, for example, to the unshifted HP 2621 keys).  If the keypad can be set to transmit or not transmit, give these codes as smkx and rmkx.  Otherwise the
   keypad is assumed to always transmit.

   The codes sent by the left arrow, right arrow, up arrow, down arrow, and home keys can be given as kcub1, kcuf1, kcuu1, kcud1, and khome respectively.  If there are function keys such
   as f0, f1, ..., f10, the codes they send can be given as kf0, kf1, ..., kf10.  If these keys have labels other than the default f0 through f10, the labels can be given  as  lf0,  lf1,
   ..., lf10.

   The codes transmitted by certain other special keys can be given:

      kll (home down),

      kbs (backspace),

      ktbc (clear all tabs),

      kctab (clear the tab stop in this column),

      kclr (clear screen or erase key),

      kdch1 (delete character),

      kdl1 (delete line),

      krmir (exit insert mode),

      kel (clear to end of line),

      ked (clear to end of screen),

      kich1 (insert character or enter insert mode),

      kil1 (insert line),

      knp (next page),

      kpp (previous page),

      kind (scroll forward/down),

      kri (scroll backward/up),

      khts (set a tab stop in this column).

   In  addition,  if the keypad has a 3 by 3 array of keys including the four arrow keys, the other five keys can be given as ka1, ka3, kb2, kc1, and kc3.  These keys are useful when the
   effects of a 3 by 3 directional pad are needed.

   Strings to program function keys can be given as pfkey, pfloc, and pfx.  A string to program screen labels should be specified as pln.  Each of these strings takes two parameters: the
   function key number to program (from 0 to 10) and the string to program it with.  Function key numbers out of this range may program undefined keys in  a  terminal  dependent  manner.
   The  difference  between the capabilities is that pfkey causes pressing the given key to be the same as the user typing the given string; pfloc causes the string to be executed by the
   terminal in local; and pfx causes the string to be transmitted to the computer.

   The capabilities nlab, lw and lh define the number of programmable screen labels and their width and height.  If there are commands to turn the labels on and off, give  them  in  smln
   and rmln.  smln is normally output after one or more pln sequences to make sure that the change becomes visible.

Tabs and Initialization

   A few capabilities are used only for tabs:

      If the terminal has hardware tabs, the command to advance to the next tab stop can be given as ht (usually control/I).

      A back-tab command which moves leftward to the preceding tab stop can be given as cbt.

       By  convention,  if the teletype modes indicate that tabs are being expanded by the computer rather than being sent to the terminal, programs should not use ht or cbt even if they
       are present, since the user may not have the tab stops properly set.

      If the terminal has hardware tabs which are initially set every n spaces when the terminal is powered up, the numeric parameter it is given, showing the number of spaces the  tabs
       are set to.

       The  it capability is normally used by the tset command to determine whether to set the mode for hardware tab expansion, and whether to set the tab stops.  If the terminal has tab
       stops that can be saved in non-volatile memory, the terminfo description can assume that they are properly set.

   Other capabilities include

      is1, is2, and is3, initialization strings for the terminal,

      iprog, the path name of a program to be run to initialize the terminal,

      and if, the name of a file containing long initialization strings.

   These strings are expected to set the terminal into modes consistent with the rest of the terminfo description.  They are normally sent to the terminal, by the init option of the tput
   program, each time the user logs in.  They will be printed in the following order:

          run the program
                 iprog

          output
                 is1 and
                 is2

          set the margins using
                 mgc or
                 smglp and smgrp or
                 smgl and smgr

          set tabs using
                 tbc and hts

          print the file
                 if

          and finally output
                 is3.

   Most initialization is done with is2.  Special terminal modes can be set up without duplicating strings by putting the common sequences in is2 and special cases in is1 and is3.

   A set of sequences that does a harder reset from a totally unknown state can be given as rs1, rs2, rf and rs3, analogous to is1 , is2 , if and is3  respectively.   These  strings  are
   output by reset option of tput, or by the reset program (an alias of tset), which is used when the terminal gets into a wedged state.  Commands are normally placed in rs1, rs2 rs3 and
   rf  only if they produce annoying effects on the screen and are not necessary when logging in.  For example, the command to set the vt100 into 80-column mode would normally be part of
   is2, but it causes an annoying glitch of the screen and is not normally needed since the terminal is usually already in 80-column mode.

   The reset program writes strings including iprog, etc., in the same order as the init program, using rs1, etc., instead of is1, etc.  If any of rs1, rs2, rs3, or rf  reset  capability
   strings are missing, the reset program falls back upon the corresponding initialization capability string.

   If  there  are commands to set and clear tab stops, they can be given as tbc (clear all tab stops) and hts (set a tab stop in the current column of every line).  If a more complex se
   quence is needed to set the tabs than can be described by this, the sequence can be placed in is2 or if.

   The tput reset command uses the same capability strings as the reset command, although the two programs (tput and reset) provide different command-line options.

   In practice, these terminfo capabilities are not often used in initialization of tabs (though they are required for the tabs program):

      Almost all hardware terminals (at least those which supported tabs) initialized those to every eight columns:

       The only exception was the AT&T 2300 series, which set tabs to every five columns.

      In particular, developers of the hardware terminals which are commonly used as models for modern terminal emulators provided documentation demonstrating that  eight  columns  were
       the standard.

      Because of this, the terminal initialization programs tput and tset use the tbc (clear_all_tabs) and hts (set_tab) capabilities directly only when the it (init_tabs) capability is
       set to a value other than eight.

Delays and Padding

   Many  older  and  slower  terminals  do  not support either XON/XOFF or DTR handshaking, including hard copy terminals and some very archaic CRTs (including, for example, DEC VT100s).
   These may require padding characters after certain cursor motions and screen changes.

   If the terminal uses xon/xoff handshaking for flow control (that is, it automatically emits ^S back to the host when its input buffers are close to full), set  xon.   This  capability
   suppresses the emission of padding.  You can also set it for memory-mapped console devices effectively that do not have a speed limit.  Padding information should still be included so
   that routines can make better decisions about relative costs, but actual pad characters will not be transmitted.

   If  pb  (padding baud rate) is given, padding is suppressed at baud rates below the value of pb.  If the entry has no padding baud rate, then whether padding is emitted or not is com
   pletely controlled by xon.

   If the terminal requires other than a null (zero) character as a pad, then this can be given as pad.  Only the first character of the pad string is used.

Status Lines

   Some terminals have an extra status line which is not normally used by software (and thus not counted in the terminal's lines capability).

   The simplest case is a status line which is cursor-addressable but not part of the main scrolling region on the screen; the Heathkit H19 has a status line of this  kind,  as  would  a
   24-line VT100 with a 23-line scrolling region set up on initialization.  This situation is indicated by the hs capability.

   Some  terminals  with  status  lines  need special sequences to access the status line.  These may be expressed as a string with single parameter tsl which takes the cursor to a given
   zero-origin column on the status line.  The capability fsl must return to the main-screen cursor positions before the last tsl.  You may need to embed the string values  of  sc  (save
   cursor) and rc (restore cursor) in tsl and fsl to accomplish this.

   The status line is normally assumed to be the same width as the width of the terminal.  If this is untrue, you can specify it with the numeric capability wsl.

   A command to erase or blank the status line may be specified as dsl.

   The Boolean capability eslok specifies that escape sequences, tabs, etc., work ordinarily in the status line.

   The ncurses implementation does not yet use any of these capabilities.  They are documented here in case they ever become important.

Line Graphics

   Many  terminals have alternate character sets useful for forms-drawing.  Terminfo and curses have built-in support for most of the drawing characters supported by the VT100, with some
   characters from the AT&T 4410v1 added.  This alternate character set may be specified by the acsc capability.

                      acsc
   ACS Name      Value   Symbol   ASCII Fallback / Glyph Name
   
   ACS_RARROW    0x2b      +      >  arrow pointing right
   ACS_LARROW    0x2c      ,      <  arrow pointing left
   ACS_UARROW    0x2d      -      ^  arrow pointing up
   ACS_DARROW    0x2e      .      v  arrow pointing down
   ACS_BLOCK     0x30      0      #  solid square block
   ACS_DIAMOND   0x60      `      +  diamond
   ACS_CKBOARD   0x61      a      :  checker board (stipple)
   ACS_DEGREE    0x66      f      \  degree symbol
   ACS_PLMINUS   0x67      g      #  plus/minus
   ACS_BOARD     0x68      h      #  board of squares
   ACS_LANTERN   0x69      i      #  lantern symbol
   ACS_LRCORNER  0x6a      j      +  lower right corner
   ACS_URCORNER  0x6b      k      +  upper right corner
   ACS_ULCORNER  0x6c      l      +  upper left corner
   ACS_LLCORNER  0x6d      m      +  lower left corner
   ACS_PLUS      0x6e      n      +  large plus or crossover
   ACS_S1        0x6f      o      ~  scan line 1
   ACS_S3        0x70      p      -  scan line 3
   ACS_HLINE     0x71      q      -  horizontal line
   ACS_S7        0x72      r      -  scan line 7
   ACS_S9        0x73      s      _  scan line 9
   ACS_LTEE      0x74      t      +  tee pointing right
   ACS_RTEE      0x75      u      +  tee pointing left
   ACS_BTEE      0x76      v      +  tee pointing up
   ACS_TTEE      0x77      w      +  tee pointing down
   ACS_VLINE     0x78      x      |  vertical line
   ACS_LEQUAL    0x79      y      <  less-than-or-equal-to
   ACS_GEQUAL    0x7a      z      >  greater-than-or-equal-to
   ACS_PI        0x7b      {      *  greek pi
   ACS_NEQUAL    0x7c      |      !  not-equal
   ACS_STERLING  0x7d      }      f  UK pound sign
   ACS_BULLET    0x7e      ~      o  bullet

   A few notes apply to the table itself:

      X/Open Curses incorrectly states that the mapping for lantern is uppercase I although Unix implementations use the lowercase i mapping.

      The DEC VT100 implemented graphics using the alternate character set feature, temporarily switching modes and sending characters in the range 0x60 (96) to  0x7e  (126)  (the  acsc
       Value column in the table).

      The AT&T terminal added graphics characters outside that range.

       Some  of  the characters within the range do not match the VT100; presumably they were used in the AT&T terminal: board of squares replaces the VT100 newline symbol, while lantern
       symbol replaces the VT100 vertical tab symbol.  The other VT100 symbols for control characters (horizontal tab, carriage return and line-feed) are not (re)used in curses.

   The best way to define a new device's graphics set is to add a column to a copy of this table for your terminal, giving the character which (when emitted between smacs/rmacs switches)
   will be rendered as the corresponding graphic.  Then read off the VT100/your terminal character pairs right to left in sequence; these become the ACSC string.

Color Handling

   The curses library functions init_pair and init_color manipulate the color pairs and color values discussed in this section (see color(3NCURSES) for details on these and related func
   tions).

   Most color terminals are either Tektronix-like or HP-like:

      Tektronix-like terminals have a predefined set of N colors (where N is usually 8), and can set character-cell foreground and background  colors  independently,  mixing  them  into
       N * N color pairs.

      On  HP-like terminals, the user must set each color pair up separately (foreground and background are not independently settable).  Up to M color pairs may be set up from 2*M dif
       ferent colors.  ANSI-compatible terminals are Tektronix-like.

   Some basic color capabilities are independent of the color method.  The numeric capabilities colors and pairs specify the maximum numbers of colors and color pairs that  can  be  dis
   played simultaneously.  The op (original pair) string resets foreground and background colors to their default values for the terminal.  The oc string resets all colors or color pairs
   to  their default values for the terminal.  Some terminals (including many PC terminal emulators) erase screen areas with the current background color rather than the power-up default
   background; these should have the Boolean capability bce.

   While the curses library works with color pairs (reflecting the inability of some devices to set foreground and background colors independently), there are separate  capabilities  for
   setting these features:

      To  change  the  current  foreground or background color on a Tektronix-type terminal, use setaf (set ANSI foreground) and setab (set ANSI background) or setf (set foreground) and
       setb (set background).  These take one parameter, the color number.  The SVr4 documentation describes only setaf/setab; the XPG4 draft says that "If the terminal supports ANSI es
       cape sequences to set background and foreground, they should be coded as setaf and setab, respectively.

      If the terminal supports other escape sequences to set background and foreground, they should be coded as setf and setb, respectively.  The vidputs and the refresh(3NCURSES) func
       tions use the setaf and setab capabilities if they are defined.

   The setaf/setab and setf/setb capabilities take a single numeric argument each.  Argument values 0-7 of setaf/setab are portably defined as follows (the middle column is the  symbolic
   #define  available  in  the header for the curses or ncurses libraries).  The terminal hardware is free to map these as it likes, but the RGB values indicate normal locations in color
   space.

                                                                        Color      #define       Value        RGB
                                                                       
                                                                       black     COLOR_BLACK       0     0,   0,   0
                                                                       red       COLOR_RED         1     max, 0,   0
                                                                       green     COLOR_GREEN       2     0,   max, 0
                                                                       yellow    COLOR_YELLOW      3     max, max, 0
                                                                       blue      COLOR_BLUE        4     0,   0,   max
                                                                       magenta   COLOR_MAGENTA     5     max, 0,   max
                                                                       cyan      COLOR_CYAN        6     0,   max, max
                                                                       white     COLOR_WHITE       7     max, max, max

   The argument values of setf/setb historically correspond to a different mapping, i.e.,

                                                                        Color      #define       Value        RGB
                                                                       
                                                                       black     COLOR_BLACK       0     0,   0,   0
                                                                       blue      COLOR_BLUE        1     0,   0,   max
                                                                       green     COLOR_GREEN       2     0,   max, 0
                                                                       cyan      COLOR_CYAN        3     0,   max, max
                                                                       red       COLOR_RED         4     max, 0,   0
                                                                       magenta   COLOR_MAGENTA     5     max, 0,   max
                                                                       yellow    COLOR_YELLOW      6     max, max, 0
                                                                       white     COLOR_WHITE       7     max, max, max

   It is important to not confuse the two sets of color capabilities; otherwise red/blue will be interchanged on the display.

   On an HP-like terminal, use scp with a color pair number parameter to set which color pair is current.

   Some terminals allow the color values to be modified:

      On a Tektronix-like terminal, the capability ccc may be present to indicate that colors can be modified.  If so, the initc capability will take a color number (0 to colors - 1)and
       three more parameters which describe the color.  These three parameters default to being interpreted as RGB (Red, Green, Blue) values.  If the Boolean capability hls  is  present,
       they are instead as HLS (Hue, Lightness, Saturation) indices.  The ranges are terminal-dependent.

      On  an HP-like terminal, initp may give a capability for changing a color pair value.  It will take seven parameters; a color pair number (0 to max_pairs - 1), and two triples de
       scribing first background and then foreground colors.  These parameters must be (Red, Green, Blue) or (Hue, Lightness, Saturation) depending on hls.

   On some color terminals, colors collide with highlights.  You can register these collisions with the ncv capability.  This is a bit mask of attributes not to be used when  colors  are
   enabled.  The correspondence with the attributes understood by curses is as follows:

                                                                             Attribute     Bit   Decimal   Set by
                                                                            
                                                                            A_STANDOUT      0         1    sgr
                                                                            A_UNDERLINE     1         2    sgr
                                                                            A_REVERSE       2         4    sgr
                                                                            A_BLINK         3         8    sgr
                                                                            A_DIM           4        16    sgr
                                                                            A_BOLD          5        32    sgr
                                                                            A_INVIS         6        64    sgr
                                                                            A_PROTECT       7       128    sgr
                                                                            A_ALTCHARSET    8       256    sgr
                                                                            A_HORIZONTAL    9       512    sgr1
                                                                            A_LEFT         10      1024    sgr1
                                                                            A_LOW          11      2048    sgr1
                                                                            A_RIGHT        12      4096    sgr1
                                                                            A_TOP          13      8192    sgr1
                                                                            A_VERTICAL     14     16384    sgr1
                                                                            A_ITALIC       15     32768    sitm

   For example, on many IBM PC consoles, the underline attribute collides with the foreground color blue and is not available in color mode.  These should have an ncv capability of 2.

   SVr4 curses does nothing with ncv, ncurses recognizes it and optimizes the output in favor of colors.

Miscellaneous

   If  the  terminal  requires  other than a null (zero) character as a pad, then this can be given as pad.  Only the first character of the pad string is used.  If the terminal does not
   have a pad character, specify npc.  Note that ncurses implements the termcap-compatible PC variable; though the application may set this value to something other than a null,  ncurses
   will test npc first and use napms if the terminal has no pad character.

   If  the  terminal  can  move up or down half a line, this can be indicated with hu (half-line up) and hd (half-line down).  This is primarily useful for superscripts and subscripts on
   hard-copy terminals.  If a hard-copy terminal can eject to the next page (form feed), give this as ff (usually control/L).

   If there is a command to repeat a given character a given number of times (to save time transmitting a large number of identical characters) this can be indicated with the  parameter
   ized  string  rep.   The  first  parameter  is  the  character  to  be  repeated  and the second is the number of times to repeat it.  Thus, tparm(repeat_char, 'x', 10) is the same as
   xxxxxxxxxx.

   If the terminal has a settable command character, such as the TEKTRONIX 4025, this can be indicated with cmdch.  A prototype command character is chosen which is used in all capabili
   ties.  This character is given in the cmdch capability to identify it.  The following convention is supported on some Unix systems: The environment is to be searched for  a  CC  vari
   able, and if found, all occurrences of the prototype character are replaced with the character in the environment variable.

   Terminal  descriptions that do not represent a specific kind of known terminal, such as switch, dialup, patch, and network, should include the gn (generic) capability so that programs
   can complain that they do not know how to talk to the terminal.  (This capability does not apply to virtual terminal descriptions for which the escape sequences are known.)

   If the terminal has a meta key which acts as a shift key, setting the 8th bit of any character transmitted, this fact can be indicated with km.  Otherwise, software will assume that
   the 8th bit is parity and it will usually be cleared.  If strings exist to turn this meta mode on and off, they can be given as smm and rmm.

   If the terminal has more lines of memory than will fit on the screen at once, the number of lines of memory can be indicated with lm.  A value of lm#0 indicates  that  the  number  of
   lines is not fixed, but that there is still more memory than fits on the screen.

   If the terminal is one of those supported by the Unix virtual terminal protocol, the terminal number can be given as vt.

   Media  copy strings which control an auxiliary printer connected to the terminal can be given as mc0: print the contents of the screen, mc4: turn off the printer, and mc5: turn on the
   printer.  When the printer is on, all text sent to the terminal will be sent to the printer.  It is undefined whether the text is also  displayed  on  the  terminal  screen  when  the
   printer is on.  A variation mc5p takes one parameter, and leaves the printer on for as many characters as the value of the parameter, then turns the printer off.  The parameter should
   not exceed 255.  All text, including mc4, is transparently passed to the printer while an mc5p is in effect.

Glitches and Brain Damage

   Hazeltine terminals, which do not allow ~ characters to be displayed should indicate hz.

   Terminals which ignore a line-feed immediately after an am wrap, such as the Concept and vt100, should indicate xenl.

   If el is required to get rid of standout (instead of merely writing normal text on top of it), xhp should be given.

   Teleray  terminals,  where  tabs turn all characters moved over to blanks, should indicate xt (destructive tabs).  Note: the variable indicating this is now dest_tabs_magic_smso; in
   older versions, it was teleray_glitch.  This glitch is also taken to mean that it is not possible to position the cursor on top of a magic cookie, that to erase standout mode it  is
   instead necessary to use delete and insert line.  The ncurses implementation ignores this glitch.

   The  Beehive  Superbee,  which  is unable to correctly transmit the escape or control/C characters, has xsb, indicating that the f1 key is used for escape and f2 for control/C.  (Only
   certain Superbees have this problem, depending on the ROM.)  Note that in older terminfo versions, this capability was called beehive_glitch; it is now no_esc_ctl_c.

   Other specific terminal problems may be corrected by adding more capabilities of the form xx.

Pitfalls of Long Entries

   Long terminfo entries are unlikely to be a problem; to date, no entry has even approached terminfo's 4096-byte string-table maximum.  Unfortunately, the termcap translations are  much
   more strictly limited (to 1023 bytes), thus termcap translations of long terminfo entries can cause problems.

   The  man pages for 4.3BSD and older versions of tgetent instruct the user to allocate a 1024-byte buffer for the termcap entry.  The entry gets null-terminated by the termcap library,
   so that makes the maximum safe length for a termcap entry 1k-1 (1023) bytes.  Depending on what the application and the termcap library being used does, and where in the termcap  file
   the terminal type that tgetent is searching for is, several bad things can happen:

   •   some termcap libraries print a warning message,

   •   some exit if they find an entry that's longer than 1023 bytes,

      some neither exit nor warn, doing nothing useful, and

      some simply truncate the entries to 1023 bytes.

   Some application programs allocate more than the recommended 1K for the termcap entry; others do not.

   Each  termcap entry has two important sizes associated with it: before tc expansion, and after tc expansion.  tc is the capability that tacks on another termcap entry to the end
   of the current one, to add on its capabilities.  If a termcap entry does not use the tc capability, then of course the two lengths are the same.

   The before tc expansion length is the most important one, because it affects more than just users of that particular terminal.  This is the length of  the  entry  as  it  exists  in
   /etc/termcap,  minus the backslash-newline pairs, which tgetent strips out while reading it.  Some termcap libraries strip off the final newline, too (GNU termcap does not).  Now sup
   pose:

      a termcap entry before expansion is more than 1023 bytes long,

      and the application has only allocated a 1k buffer,

      and the termcap library (like the one in BSD/OS 1.1 and GNU) reads the whole entry into the buffer, no matter what its length, to see if it is the entry it wants,

      and tgetent is searching for a terminal type that either is the long entry, appears in the termcap file after the long entry, or does not appear in the file at all (so  that  tge
       tent has to search the whole termcap file).

   Then tgetent will overwrite memory, perhaps its stack, and probably core dump the program.  Programs like telnet are particularly vulnerable; modern telnets pass along values like the
   terminal  type automatically.  The results are almost as undesirable with a termcap library, like SunOS 4.1.3 and Ultrix 4.4, that prints warning messages when it reads an overly long
   termcap entry.  If a termcap library truncates long entries, like OSF/1 3.0, it is immune to dying here but will return incorrect data for the terminal.

   The after tc expansion length will have a similar effect to the above, but only for people who actually set TERM to that terminal type, since tgetent only does tc  expansion  once
   it is found the terminal type it was looking for, not while searching.

   In summary, a termcap entry that is longer than 1023 bytes can cause, on various combinations of termcap libraries and applications, a core dump, warnings, or incorrect operation.  If
   it is too long even before tc expansion, it will have this effect even for users of some other terminal types and users whose TERM variable does not have a termcap entry.

   When  in  -C (translate to termcap) mode, the ncurses implementation of tic(1) issues warning messages when the pre-tc length of a termcap translation is too long.  The -c (check) op
   tion also checks resolved (after tc expansion) lengths.

FILES

   /etc/terminfo
          compiled terminal description database directory

EXTENSIONS

   Searching for terminal descriptions in $HOME/.terminfo and TERMINFO_DIRS is not supported by older implementations.

   Some SVr4 curses implementations, and all previous to SVr4, do not interpret the %A and %O operators in parameter strings.

   SVr4/XPG4 do not specify whether msgr licenses movement while in an alternate-character-set mode (such modes may, among other things, map CR and NL to characters that do  not  trigger
   local  motions).  The ncurses implementation ignores msgr in ALTCHARSET mode.  This raises the possibility that an XPG4 implementation making the opposite interpretation may need ter
   minfo entries made for ncurses to have msgr turned off.

   The ncurses library handles insert-character and insert-character modes in a slightly non-standard way to get better update efficiency.  See  the  Insert/Delete  Character  subsection
   above.

   The parameter substitutions for set_clock and display_clock are not documented in SVr4 or X/Open Curses.  They are deduced from the documentation for the AT&T 505 terminal.

   Be careful assigning the kmous capability.  The ncurses library wants to interpret it as KEY_MOUSE, for use by terminals and emulators like xterm that can return mouse-tracking infor
   mation in the keyboard-input stream.

   X/Open Curses does not mention italics.  Portable applications must assume that numeric capabilities are signed 16-bit values.  This includes the no_color_video (ncv) capability.  The
   32768  mask  value  used  for italics with ncv can be confused with an absent or canceled ncv.  If italics should work with colors, then the ncv value must be specified, even if it is
   zero.

   Different commercial ports of terminfo and curses support different subsets of X/Open Curses and (in some cases) different extensions.  Here is a summary, accurate as of October 1995,
   after which the commercial Unix market contracted and lost diversity.

      SVr4, Solaris, and ncurses support all SVr4 capabilities.

      IRIX supports the SVr4 set and adds one undocumented extended string capability (set_pglen).

      SVr1 and Ultrix support a restricted subset of terminfo capabilities.  The Booleans end with xon_xoff; the numerics with width_status_line; and the strings with prtr_non.

      HP/UX supports the SVr1 subset, plus the SVr[234] numerics num_labels, label_height, label_width, plus function keys 11 through 63, plus plab_norm, label_on, and label_off, plus a
       number of incompatible string table extensions.

      AIX supports the SVr1 subset, plus function keys 11 through 63, plus a number of incompatible string table extensions.

      OSF/1 supports both the SVr4 set and the AIX extensions.

PORTABILITY

   Do not count on compiled (binary) terminfo entries being portable between commercial Unix systems.  At least two implementations of terminfo (those of HP-UX  and  AIX)  diverged  from
   those of other System V Unices after SVr1, adding extension capabilities to the string table that (in the binary format) collide with subsequent System V and X/Open Curses extensions.

AUTHORS

   Zeyd M. Ben-Halim, Eric S. Raymond, Thomas E. Dickey.  Based on pcurses by Pavel Curtis.

SEE ALSO

   infocmp(1), tabs(1), tic(1), ncurses(3NCURSES), color(3NCURSES), terminfo(3NCURSES), curses_variables(3NCURSES), printf(3), terminfo_variables(3NCURSES), term(5), user_caps(5)

ncurses 6.5 2024-05-11 terminfo(5)