curs_termcap 3x
curs_termcap(3x) curs_termcap(3x)
NAME
tgetent, tgetflag, tgetnum, tgetstr, tgoto, tputs - direct
curses interface to the terminfo capability database
SYNOPSIS
#include <curses.h>
#include <term.h>
extern char PC; extern char * UP; extern char * BC; extern
short ospeed;
int tgetent(char *bp, const char *name);
int tgetflag(char *id);
int tgetnum(char *id);
char *tgetstr(char *id, char **area);
char *tgoto(const char *cap, int col, int row);
int tputs(const char *str, int affcnt, int (*putc)(int));
DESCRIPTION
These routines are included as a conversion aid for pro-
grams that use the termcap library. Their parameters are
the same and the routines are emulated using the terminfo
database. Thus, they can only be used to query the capa-
bilities of entries for which a terminfo entry has been
compiled.
The tgetent routine loads the entry for name. It returns
1 on success, 0 if there is no such entry, and -1 if the
terminfo database could not be found. The emulation
ignores the buffer pointer bp.
The tgetflag routine gets the boolean entry for id, or
zero if it is not available.
The tgetnum routine gets the numeric entry for id, or -1
if it is not available.
The tgetstr routine returns the string entry for id, or
zero if it is not available. Use tputs to output the
returned string. The return value will also be copied to
the buffer pointed to by area, and the area value will be
updated to point past the null ending this value.
Only the first two characters of the id parameter of tget-
flag, tgetnum and tgetstr are compared in lookups.
The tgoto routine instantiates the parameters into the
given capability. The output from this routine is to be
passed to tputs.
The tputs routine is described on the curs_terminfo(3x)
manual page. It can retrieve capabilities by either term-
cap or terminfo name.
The variables PC, UP and BC are set by tgetent to the ter-
minfo entry's data for pad_char, cursor_up and
backspace_if_not_bs, respectively. UP is not used by
ncurses. PC is used in the tdelay_output function. BC is
used in the tgoto emulation. The variable ospeed is set
by ncurses in a system-specific coding to reflect the ter-
minal speed.
RETURN VALUE
Except where explicitly noted, routines that return an
integer return ERR upon failure and OK (SVr4 only
specifies "an integer value other than ERR") upon success-
ful completion.
Routines that return pointers return NULL on error.
BUGS
If you call tgetstr to fetch ca or any other parameterized
string, be aware that it will be returned in terminfo
notation, not the older and not-quite-compatible termcap
notation. This won't cause problems if all you do with it
is call tgoto or tparm, which both expand terminfo-style
strings as terminfo. (The tgoto function, if configured
to support termcap, will check if the string is indeed
terminfo-style by looking for "%p" parameters or "$<..>"
delays, and invoke a termcap-style parser if the string
does not appear to be terminfo).
Because terminfo conventions for representing padding in
string capabilities differ from termcap's, tputs("50");
will put out a literal "50" rather than busy-waiting for
50 milliseconds. Cope with it.
Note that termcap has nothing analogous to terminfo's sgr
string. One consequence of this is that termcap applica-
tions assume me (terminfo sgr0) does not reset the alter-
nate character set. This implementation checks for, and
modifies the data shown to the termcap interface to accom-
modate termcap's limitation in this respect.
PORTABILITY
The XSI Curses standard, Issue 4 describes these func-
tions. However, they are marked TO BE WITHDRAWN and may
be removed in future versions.
Neither the XSI Curses standard nor the SVr4 man pages
documented the return values of tgetent correctly, though
all three were in fact returned ever since SVr1. In par-
ticular, an omission in the XSI Curses documentation has
been misinterpreted to mean that tgetent returns OK or
ERR. Because the purpose of these functions is to provide
compatibility with the termcap library, that is a defect
in XCurses, Issue 4, Version 2 rather than in ncurses.
External variables are provided for support of certain
termcap applications. However, termcap applications' use
of those variables is poorly documented, e.g., not distin-
guishing between input and output. In particular, some
applications are reported to declare and/or modify ospeed.
SEE ALSO
curses(3x), terminfo(5), putc(3S).
curs_termcap(3x)
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