.\" authorization. *
.\"***************************************************************************
.\"
-.\" $Id: curs_termcap.3x,v 1.48 2021/01/09 11:07:15 tom Exp $
+.\" $Id: curs_termcap.3x,v 1.52 2021/12/25 21:31:00 tom Exp $
.TH curs_termcap 3X ""
.ie \n(.g .ds `` \(lq
.el .ds `` ``
.hy 0
.ds n 5
.SH NAME
-\fBPC\fR,
-\fBUP\fR,
-\fBBC\fR,
-\fBospeed\fR,
-\fBtgetent\fR,
-\fBtgetflag\fR,
-\fBtgetnum\fR,
-\fBtgetstr\fR,
-\fBtgoto\fR,
-\fBtputs\fR \- \fBcurses\fR emulation of termcap
+\fBPC\fP,
+\fBUP\fP,
+\fBBC\fP,
+\fBospeed\fP,
+\fBtgetent\fP,
+\fBtgetflag\fP,
+\fBtgetnum\fP,
+\fBtgetstr\fP,
+\fBtgoto\fP,
+\fBtputs\fP \- \fBcurses\fP emulation of termcap
.ad
.hy
.SH SYNOPSIS
-\fB#include <curses.h>\fR
+\fB#include <curses.h>\fP
.br
-\fB#include <term.h>\fR
+\fB#include <term.h>\fP
.sp
-\fBextern char PC;\fR
+\fBextern char PC;\fP
.br
-\fBextern char * UP;\fR
+\fBextern char * UP;\fP
.br
-\fBextern char * BC;\fR
+\fBextern char * BC;\fP
.br
-\fBextern @NCURSES_OSPEED@ ospeed;\fR
+\fBextern @NCURSES_OSPEED@ ospeed;\fP
.sp
-\fBint tgetent(char *\fP\fIbp\fP\fB, const char *\fP\fIname\fP\fB);\fR
+\fBint tgetent(char *\fP\fIbp\fP\fB, const char *\fP\fIname\fP\fB);\fP
.br
-\fBint tgetflag(const char *\fP\fIid\fP\fB);\fR
+\fBint tgetflag(const char *\fP\fIid\fP\fB);\fP
.br
-\fBint tgetnum(const char *\fP\fIid\fP\fB);\fR
+\fBint tgetnum(const char *\fP\fIid\fP\fB);\fP
.br
-\fBchar *tgetstr(const char *\fP\fIid\fP\fB, char **\fP\fIarea\fP\fB);\fR
+\fBchar *tgetstr(const char *\fP\fIid\fP\fB, char **\fP\fIarea\fP\fB);\fP
.br
-\fBchar *tgoto(const char *\fP\fIcap\fP\fB, int \fP\fIcol\fP\fB, int \fP\fIrow\fP\fB);\fR
+\fBchar *tgoto(const char *\fP\fIcap\fP\fB, int \fP\fIcol\fP\fB, int \fP\fIrow\fP\fB);\fP
.br
-\fBint tputs(const char *\fP\fIstr\fP\fB, int \fP\fIaffcnt\fP\fB, int (*\fP\fIputc\fP\fB)(int));\fR
+\fBint tputs(const char *\fP\fIstr\fP\fB, int \fP\fIaffcnt\fP\fB, int (*\fP\fIputc\fP\fB)(int));\fP
.br
.SH DESCRIPTION
These routines are included as a conversion aid for programs that use
-the \fItermcap\fR library.
+the \fItermcap\fP library.
Their parameters are the same, but the
-routines are emulated using the \fIterminfo\fR database.
+routines are emulated using the \fIterminfo\fP database.
Thus, they
can only be used to query the capabilities of entries for which a
terminfo entry has been compiled.
.SS INITIALIZATION
.PP
-The \fBtgetent\fR routine loads the entry for \fIname\fR.
+The \fBtgetent\fP routine loads the entry for \fIname\fP.
It returns:
.RS 3
.TP 3
This differs from the \fItermcap\fP library in two ways:
.RS 3
.bP
-The emulation ignores the buffer pointer \fIbp\fR.
+The emulation ignores the buffer pointer \fIbp\fP.
The \fItermcap\fP library would store a copy of the terminal
description in the area referenced by this pointer.
However, ncurses stores its terminal descriptions in compiled
.RE
.SS CAPABILITY VALUES
.PP
-The \fBtgetflag\fR routine gets the boolean entry for \fIid\fR,
+The \fBtgetflag\fP routine gets the boolean entry for \fIid\fP,
or zero if it is not available.
.PP
-The \fBtgetnum\fR routine gets the numeric entry for \fIid\fR,
+The \fBtgetnum\fP routine gets the numeric entry for \fIid\fP,
or \-1 if it is not available.
.PP
-The \fBtgetstr\fR routine returns the string entry for \fIid\fR,
+The \fBtgetstr\fP routine returns the string entry for \fIid\fP,
or zero if it is not available.
-Use \fBtputs\fR to output the returned string.
+Use \fBtputs\fP to output the returned string.
The \fIarea\fP parameter is used as follows:
.RS 3
.bP
If either check fails, the \fIarea\fP parameter is ignored.
.bP
If the checks succeed, ncurses also copies the return value to
-the buffer pointed to by \fIarea\fR,
-and the \fIarea\fR value will be updated to point past the null ending
+the buffer pointed to by \fIarea\fP,
+and the \fIarea\fP value will be updated to point past the null ending
this value.
.bP
The return value itself is an address in the terminal description which
is loaded into memory.
.RE
.PP
-Only the first two characters of the \fBid\fR parameter of
-\fBtgetflag\fR,
-\fBtgetnum\fR and
-\fBtgetstr\fR are compared in lookups.
+Only the first two characters of the \fBid\fP parameter of
+\fBtgetflag\fP,
+\fBtgetnum\fP and
+\fBtgetstr\fP are compared in lookups.
.SS FORMATTING CAPABILITIES
.PP
-The \fBtgoto\fR routine expands the given capability using the parameters.
+The \fBtgoto\fP routine expands the given capability using the parameters.
.bP
Because the capability may have padding characters,
-the output of \fBtgoto\fP should be passed to \fBtputs\fR
-rather than some other output function such as \fBprintf\fP.
+the output of \fBtgoto\fP should be passed to \fBtputs\fP
+rather than some other output function such as \fBprintf\fP(3).
.bP
While \fBtgoto\fP is assumed to be used for the two-parameter
cursor positioning capability,
However, \fBtparm\fP is not a \fItermcap\fP feature,
and portable \fItermcap\fP applications should not rely upon its availability.
.PP
-The \fBtputs\fR routine is described on the \fBcurs_terminfo\fR(3X) manual
+The \fBtputs\fP routine is described on the \fBcurs_terminfo\fP(3X) manual
page.
It can retrieve capabilities by either termcap or terminfo name.
.SS GLOBAL VARIABLES
.PP
The variables
-\fBPC\fR,
-\fBUP\fR and
-\fBBC\fR
-are set by \fBtgetent\fR to the terminfo entry's data for
-\fBpad_char\fR,
-\fBcursor_up\fR and
-\fBbackspace_if_not_bs\fR,
+\fBPC\fP,
+\fBUP\fP and
+\fBBC\fP
+are set by \fBtgetent\fP to the terminfo entry's data for
+\fBpad_char\fP,
+\fBcursor_up\fP and
+\fBbackspace_if_not_bs\fP,
respectively.
-\fBUP\fR is not used by ncurses.
-\fBPC\fR is used in the \fBtdelay_output\fR function.
-\fBBC\fR is used in the \fBtgoto\fR emulation.
-The variable \fBospeed\fR is set by ncurses in a system-specific coding
+\fBUP\fP is not used by ncurses.
+\fBPC\fP is used in the \fBtdelay_output\fP function.
+\fBBC\fP is used in the \fBtgoto\fP emulation.
+The variable \fBospeed\fP is set by ncurses in a system-specific coding
to reflect the terminal speed.
.
.SH RETURN VALUE
Except where explicitly noted,
-routines that return an integer return \fBERR\fR upon failure and \fBOK\fR
-(SVr4 only specifies "an integer value other than \fBERR\fR") upon successful
+routines that return an integer return \fBERR\fP upon failure and \fBOK\fP
+(SVr4 only specifies "an integer value other than \fBERR\fP") upon successful
completion.
.PP
-Routines that return pointers return \fBNULL\fR on error.
+Routines that return pointers return \fBNULL\fP on error.
.SH BUGS
-If you call \fBtgetstr\fR to fetch \fBca\fR or any other parameterized string,
+If you call \fBtgetstr\fP to fetch \fBca\fP 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 will not cause problems if all
-you do with it is call \fBtgoto\fR or \fBtparm\fR, which both expand
+you do with it is call \fBtgoto\fP or \fBtparm\fP, which both expand
terminfo-style strings as terminfo.
-(The \fBtgoto\fR function, if configured to support termcap, will check
+(The \fBtgoto\fP 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).
.PP
Because terminfo conventions for representing padding in string capabilities
-differ from termcap's, \fBtputs("50");\fR will put out a literal \*(``50\*('' rather
-than busy-waiting for 50 milliseconds.
-Cope with it.
+differ from termcap's,
+users can be surprised:
+.bP
+\fBtputs("50")\fP in a terminfo system will put out a literal \*(``50\*(''
+rather than busy-waiting for 50 milliseconds.
+.bP
+However, if ncurses is configured to support termcap,
+it may also have been configured to support the BSD-style padding.
+.IP
+In that case, \fBtputs\fP inspects strings passed to it,
+looking for digits at the beginning of the string.
+.IP
+\fBtputs("50")\fP in a termcap system may wait for 50 milliseconds
+rather than put out a literal \*(``50\*(''
.PP
-Note that termcap has nothing analogous to terminfo's \fBsgr\fR string.
-One consequence of this is that termcap applications assume \fRme\fR
-(terminfo \fBsgr0\fR) does not reset the alternate character set.
+Note that termcap has nothing analogous to terminfo's \fBsgr\fP string.
+One consequence of this is that termcap applications assume \fBme\fP
+(terminfo \fBsgr0\fP) does not reset the alternate character set.
This implementation checks for, and modifies the data shown to the
termcap interface to accommodate termcap's limitation in this respect.
.SH PORTABILITY
(along with \fBvwprintw\fP and \fBvwscanw\fP) as withdrawn.
.PP
Neither the XSI Curses standard nor the SVr4 man pages documented the return
-values of \fBtgetent\fR correctly, though all three were in fact returned ever
+values of \fBtgetent\fP correctly, though all three were in fact returned ever
since SVr1.
In particular, an omission in the XSI Curses documentation has been
-misinterpreted to mean that \fBtgetent\fR returns \fBOK\fR or \fBERR\fR.
+misinterpreted to mean that \fBtgetent\fP returns \fBOK\fP or \fBERR\fP.
Because the purpose of these functions is to provide compatibility with
-the \fItermcap\fR library, that is a defect in XCurses, Issue 4, Version 2
+the \fItermcap\fP library, that is a defect in XCurses, Issue 4, Version 2
rather than in ncurses.
.SS Compatibility with BSD Termcap
.PP
However, termcap applications' use of those variables is poorly documented,
e.g., not distinguishing between input and output.
In particular, some applications are reported to declare and/or
-modify \fBospeed\fR.
+modify \fBospeed\fP.
.PP
-The comment that only the first two characters of the \fBid\fR parameter
+The comment that only the first two characters of the \fBid\fP parameter
are used escapes many application developers.
The original BSD 4.2 termcap library (and historical relics thereof)
did not require a trailing null NUL on the parameter name passed
However, there were two different termcap.h header files in the BSD
sources:
.bP
-One was used internally by the \fIjove\fP editor in 2BSD through 4.4BSD.
+One was used internally by the \fBjove\fP editor in 2BSD through 4.4BSD.
It defined global symbols for the termcap variables which it used.
.bP
The other appeared in 4.4BSD Lite Release 2 (mid-1993)
but in that instance, it was \fIlibedit\fP which differed from BSD termcap.
.PP
A copy of GNU termcap 1.3 was bundled with \fIbash\fP in mid-1993,
-to support the \fIreadline\fP library.
+to support the \fBreadline\fP(3) library.
.PP
A termcap.h file was provided in ncurses 1.8.1 (November 1993).
-That reflected influence by \fIemacs\fP (rather than \fIjove\fP)
+That reflected influence by \fBemacs\fP(1) (rather than \fBjove\fP(1))
and GNU termcap:
.bP
-it provided declarations for a few global symbols used by \fIemacs\fP
+it provided declarations for a few global symbols used by \fBemacs\fP
.bP
it provided function prototypes (using \fBconst\fP).
.bP
which must be taken into account by programs which can work with all
termcap library interfaces.
.SH SEE ALSO
-\fBcurses\fR(3X),
-\fBputc\fR(3),
-\fBterm_variables\fR(3X),
-\fBterminfo\fR(\*n).
+\fBcurses\fP(3X),
+\fBputc\fP(3),
+\fBterm_variables\fP(3X),
+\fBterminfo\fP(\*n).
.sp
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