1curs_termcap(3X) curs_termcap(3X)
2
6 PC, UP, BC, ospeed, tgetent, tgetflag, tgetnum, tgetstr, tgoto, tputs -
7 direct curses interface to the terminfo capability database
8
10 #include <curses.h>
11 #include <term.h>
12 extern char PC;
14 extern char * UP;
15 extern char * BC;
16 extern unsigned ospeed;
17 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
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 INITIALIZATION
33 The tgetent routine loads the entry for name. It returns:
34 1 on success,
36 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 -1 if the terminfo database could not be found.
41 This differs from the termcap library in two ways:
43 · 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 · 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 CAPABILITY VALUES
56 The tgetflag routine gets the boolean entry for id, or zero if it is
57 not available.
58 The tgetnum routine gets the numeric entry for id, or -1 if it is not
60 available.
61 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 Only the first two characters of the id parameter of tgetflag, tgetnum
68 and tgetstr are compared in lookups.
69 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 The tputs routine is described on the curs_terminfo(3X) manual page.
75 It can retrieve capabilities by either termcap or terminfo name.
76 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
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 Routines that return pointers return NULL on error.
90
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 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 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
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 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 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 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 · 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 · This implementation disallows matches by the termcap interface
144 against extended capability names which are longer than two charac‐
145 ters.
146
148 curses(3X), terminfo(5), term_variables(3X), putc(3).
149 http://invisible-island.net/ncurses/tctest.html
151 curs_termcap(3X)