1curs_termcap(3X)                                              curs_termcap(3X)
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NAME

6       PC, UP, BC, ospeed, tgetent, tgetflag, tgetnum, tgetstr, tgoto, tputs -
7       direct curses interface to the terminfo capability database
8

SYNOPSIS

10       #include <curses.h>
11       #include <term.h>
12
13       extern char PC;
14       extern char * UP;
15       extern char * BC;
16       extern unsigned ospeed;
17
18       int tgetent(char *bp, const char *name);
19       int tgetflag(char *id);
20       int tgetnum(char *id);
21       char *tgetstr(char *id, char **area);
22       char *tgoto(const char *cap, int col, int row);
23       int tputs(const char *str, int affcnt, int (*putc)(int));
24

DESCRIPTION

26       These routines are included as a conversion aid for programs  that  use
27       the  termcap  library.   Their parameters are the same and the routines
28       are emulated using the terminfo database.  Thus, they can only be  used
29       to  query  the  capabilities  of entries for which a terminfo entry has
30       been compiled.
31
32   INITIALIZATION
33       The tgetent routine loads the entry for name.  It returns:
34
35          1  on success,
36
37          0  if there is no such entry (or that it is a generic  type,  having
38             too little information for curses applications to run), and
39
40          -1 if the terminfo database could not be found.
41
42       This differs from the termcap library in two ways:
43
44          ·   The  emulation  ignores  the buffer pointer bp.  The termcap li‐
45              brary would store a copy of the terminal description in the area
46              referenced  by this pointer.  However, ncurses stores its termi‐
47              nal descriptions in compiled binary form, which is not the  same
48              thing.
49
50          ·   There is a difference in return codes.  The termcap library does
51              not check if the terminal description is marked with the generic
52              capability,  or  if the terminal description has cursor-address‐
53              ing.
54
55   CAPABILITY VALUES
56       The tgetflag routine gets the boolean entry for id, or zero  if  it  is
57       not available.
58
59       The  tgetnum  routine gets the numeric entry for id, or -1 if it is not
60       available.
61
62       The tgetstr routine returns the string entry for id, or zero if  it  is
63       not  available.   Use  tputs to output the returned string.  The return
64       value will also be copied to the buffer pointed to  by  area,  and  the
65       area value will be updated to point past the null ending this value.
66
67       Only  the first two characters of the id parameter of tgetflag, tgetnum
68       and tgetstr are compared in lookups.
69
70   FORMATTING CAPABILITIES
71       The tgoto routine instantiates the parameters into the given  capabili‐
72       ty.  The output from this routine is to be passed to tputs.
73
74       The  tputs  routine  is described on the curs_terminfo(3X) manual page.
75       It can retrieve capabilities by either termcap or terminfo name.
76
77   GLOBAL VARIABLES
78       The variables PC, UP and BC are set by tgetent to the terminfo  entry's
79       data for pad_char, cursor_up and backspace_if_not_bs, respectively.  UP
80       is not used by ncurses.  PC is used in the tdelay_output function.   BC
81       is  used in the tgoto emulation.  The variable ospeed is set by ncurses
82       in a system-specific coding to reflect the terminal speed.
83

RETURN VALUE

85       Except where explicitly noted, routines that return an  integer  return
86       ERR  upon  failure  and OK (SVr4 only specifies "an integer value other
87       than ERR") upon successful completion.
88
89       Routines that return pointers return NULL on error.
90

BUGS

92       If you call tgetstr to fetch ca or any other parameterized  string,  be
93       aware  that it will be returned in terminfo notation, not the older and
94       not-quite-compatible termcap notation.  This will not cause problems if
95       all  you do with it is call tgoto or tparm, which both expand terminfo-
96       style strings as terminfo.  (The tgoto function, if configured to  sup‐
97       port  termcap,  will  check  if  the string is indeed terminfo-style by
98       looking for "%p" parameters or "$<..>" delays, and  invoke  a  termcap-
99       style parser if the string does not appear to be terminfo).
100
101       Because  terminfo  conventions for representing padding in string capa‐
102       bilities differ from termcap's, tputs("50"); will  put  out  a  literal
103       "50" rather than busy-waiting for 50 milliseconds.  Cope with it.
104
105       Note  that termcap has nothing analogous to terminfo's sgr string.  One
106       consequence of this is that termcap applications  assume  me  (terminfo
107       sgr0)  does not reset the alternate character set.  This implementation
108       checks for, and modifies the data shown to the termcap interface to ac‐
109       commodate termcap's limitation in this respect.
110

PORTABILITY

112       The  XSI  Curses standard, Issue 4 describes these functions.  However,
113       they are marked TO BE WITHDRAWN and may be removed in future versions.
114
115       Neither the XSI Curses standard nor the SVr4 man pages  documented  the
116       return  values  of tgetent correctly, though all three were in fact re‐
117       turned ever since SVr1.  In particular, an omission in the  XSI  Curses
118       documentation  has  been misinterpreted to mean that tgetent returns OK
119       or ERR.  Because the purpose of these functions is to provide  compati‐
120       bility  with the termcap library, that is a defect in XCurses, Issue 4,
121       Version 2 rather than in ncurses.
122
123       External variables are provided for support of certain termcap applica‐
124       tions.  However, termcap applications' use of those variables is poorly
125       documented, e.g., not distinguishing between input and output.  In par‐
126       ticular,  some  applications  are reported to declare and/or modify os‐
127       peed.
128
129       The comment that only the first two characters of the id parameter  are
130       used escapes many application developers.  The original BSD 4.2 termcap
131       library (and historical relics thereof) did not require a trailing null
132       NUL  on  the  parameter  name  passed to tgetstr, tgetnum and tgetflag.
133       Some applications assume that the termcap interface  does  not  require
134       the trailing NUL for the parameter name.  Taking into account these is‐
135       sues:
136
137       ·   As a special case,  tgetflag  matched  against  a  single-character
138           identifier  provided  that  was at the end of the terminal descrip‐
139           tion.  You should not rely upon this behavior in portable programs.
140           This  implementation disallows matches against single-character ca‐
141           pability names.
142
143       ·   This implementation disallows  matches  by  the  termcap  interface
144           against extended capability names which are longer than two charac‐
145           ters.
146

SEE ALSO

148       curses(3X), terminfo(5), term_variables(3X), putc(3).
149
150       http://invisible-island.net/ncurses/tctest.html
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154                                                              curs_termcap(3X)
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