.\"***************************************************************************
-.\" Copyright (c) 1999-2016,2017 Free Software Foundation, Inc. *
+.\" Copyright 2018,2020 Thomas E. Dickey *
+.\" Copyright 1998-2016,2017 Free Software Foundation, Inc. *
.\" *
.\" Permission is hereby granted, free of charge, to any person obtaining a *
.\" copy of this software and associated documentation files (the *
.\" authorization. *
.\"***************************************************************************
.\"
-.\" $Id: curs_terminfo.3x,v 1.55 2017/03/31 15:16:15 tom Exp $
+.\" $Id: curs_terminfo.3x,v 1.67 2020/11/07 23:49:07 tom Exp $
.TH curs_terminfo 3X ""
.ie \n(.g .ds `` \(lq
.el .ds `` ``
.ie \n(.g .ds '' \(rq
.el .ds '' ''
.de bP
-.IP \(bu 4
+.ie n .IP \(bu 4
+.el .IP \(bu 2
..
.ds n 5
.na
.hy
.SH SYNOPSIS
.nf
-\fB#include <curses.h>\fR
-.br
\fB#include <term.h>\fR
.sp
\fBTERMINAL *cur_term;\fR
.SH DESCRIPTION
These low-level routines must be called by programs that have to deal
directly with the \fBterminfo\fR database to handle certain terminal
-capabilities, such as programming function keys. For all other
+capabilities, such as programming function keys.
+For all other
functionality, \fBcurses\fR routines are more suitable and their use is
recommended.
+.PP
+None of these functions use (or are aware of) multibyte character strings
+such as UTF-8:
+.bP
+capability names use the POSIX portable character set
+.bP
+capability string values have no associated encoding;
+they are strings of 8-bit characters.
.SS Initialization
.PP
Initially, \fBsetupterm\fR should be called.
\fBlines\fR and \fBcolumns\fR specified in \fBterminfo\fR are used.
.bP
Otherwise, if the environment variables \fBLINES\fR and \fBCOLUMNS\fR
-exist, their values are used. If these environment variables do not
+exist, their values are used.
+If these environment variables do not
exist and the program is running in a window, the current window size
-is used. Otherwise, if the environment variables do not exist, the
+is used.
+Otherwise, if the environment variables do not exist, the
values for \fBlines\fR and \fBcolumns\fR specified in the
\fBterminfo\fR database are used.
.PP
-Parameterized strings should be passed through \fBtparm\fR to instantiate them.
-All \fBterminfo\fR strings [including the output of \fBtparm\fR] should be printed
+Parameterized strings should be passed through \fBtparm\fR to instantiate them.
+All \fBterminfo\fR strings
+(including the output of \fBtparm\fR)
+should be printed
with \fBtputs\fR or \fBputp\fR.
Call \fBreset_shell_mode\fR to restore the
tty modes before exiting [see \fBcurs_kernel\fR(3X)].
.IP
If \fIerrret\fR is
null, \fBsetupterm\fR prints an error message upon finding an error
-and exits. Thus, the simplest call is:
+and exits.
+Thus, the simplest call is:
.sp
\fBsetupterm((char *)0, 1, (int *)0);\fR,
.sp
It returns the old value of \fBcur_term\fR.
.PP
The \fBdel_curterm\fR routine frees the space pointed to by
-\fIoterm\fR and makes it available for further use. If \fIoterm\fR is
+\fIoterm\fR and makes it available for further use.
+If \fIoterm\fR is
the same as \fBcur_term\fR, references to any of the \fBterminfo\fR
boolean, numeric, and string variables thereafter may refer to invalid
memory locations until another \fBsetupterm\fR has been called.
The \fBtputs\fR routine applies padding information to the string
\fIstr\fR and outputs it:
.bP
-The \fIstr\fR must be a terminfo string
-variable or the return value from \fBtparm\fR, \fBtgetstr\fR, or
-\fBtgoto\fR.
+The \fIstr\fR parameter must be a terminfo string
+variable or the return value from
+\fBtparm\fR, \fBtiparm\fP, \fBtgetstr\fR, or \fBtgoto\fR.
+.IP
+The \fBtgetstr\fP and \fBtgoto\fP functions are part of the \fItermcap\fP
+interface,
+which happens to share this function name with the \fIterminfo\fP interface.
.bP
\fIaffcnt\fR is the number of lines affected, or 1 if
not applicable.
.PP
The \fBvidputs\fR routine displays the string on the terminal in the
video attribute mode \fIattrs\fR, which is any combination of the
-attributes listed in \fBcurses\fR(3X). The characters are passed to
+attributes listed in \fBcurses\fR(3X).
+The characters are passed to
the \fBputchar\fR-like routine \fIputc\fR.
.PP
The \fBvidattr\fR routine is like the \fBvidputs\fR routine, except
that it outputs through \fBputchar\fR.
.PP
-The \fBvid_attr\fR and \fBvid_puts\fR routines correspond to vidattr and vidputs,
-respectively.
+The \fBvid_attr\fR and \fBvid_puts\fR routines correspond
+to vidattr and vidputs, respectively.
They use a set of arguments for representing the video attributes plus color,
i.e.,
.bP
this implementation allows \fIopts\fP to be used as a pointer to \fBint\fP,
which overrides the \fIpair\fP (\fBshort\fP) argument.
.PP
-The \fBmvcur\fR routine provides low-level cursor motion. It takes
+The \fBmvcur\fR routine provides low-level cursor motion.
+It takes
effect immediately (rather than at the next refresh).
.\" ***************************************************************************
.SS Terminal Capability Functions
.bP
the short terminfo names (\*(``codes\*(''),
.bP
-the \fBtermcap\fR names (\*(``names\*('', and
+the \fBtermcap\fR names (\*(``names\*(''), and
.bP
the long terminfo names (\*(``fnames\*('')
.PP
.RE
.SH RETURN VALUE
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
-completion, unless otherwise noted in the preceding routine descriptions.
+(SVr4 only specifies \*(``an integer value other than \fBERR\fR\*('')
+upon successful completion,
+unless otherwise noted in the preceding routine descriptions.
.PP
Routines that return pointers always return \fBNULL\fR on error.
.PP
X/Open states that \fBtputs\fP ignores the return value
of the output function \fIputc\fP.
.RE
+.SH HISTORY
+.PP
+SVr2 introduced the terminfo feature.
+Its programming manual mentioned these low-level functions:
+.TS
+l l
+_ _
+l l.
+\fBFunction\fR \fBDescription\fR
+fixterm restore tty to \*(``in curses\*('' state
+gettmode establish current tty modes
+mvcur low level cursor motion
+putp T{
+utility function that uses \fBtputs\fP to send characters via \fBputchar\fP.
+T}
+resetterm set tty modes to \*(``out of curses\*('' state
+resetty reset tty flags to stored value
+saveterm save current modes as \*(``in curses\*('' state
+savetty store current tty flags
+setterm establish terminal with given type
+setupterm establish terminal with given type
+tparm instantiate a string expression with parameters
+tputs apply padding information to a string
+vidattr like \fBvidputs\fP, but outputs through \fBputchar\fP
+vidputs T{
+output a string to put terminal in a specified video attribute mode
+T}
+.TE
+.PP
+The programming manual also mentioned
+functions provided for termcap compatibility
+(commenting that they \*(``may go away at a later date\*(''):
+.TS
+l l
+_ _
+l l.
+\fBFunction\fR \fBDescription\fR
+tgetent look up termcap entry for given \fIname\fP
+tgetflag get boolean entry for given \fIid\fP
+tgetnum get numeric entry for given \fIid\fP
+tgetstr get string entry for given \fIid\fP
+tgoto apply parameters to given capability
+tputs T{
+apply padding to capability, calling a function to put characters
+T}
+.TE
+.PP
+Early terminfo programs obtained capability values from the
+\fBTERMINAL\fP structure initialized by \fBsetupterm\fR.
+.PP
+SVr3 extended terminfo by adding functions to retrieve capability values
+(like the termcap interface),
+and reusing tgoto and tputs:
+.TS
+l l
+_ _
+l l.
+\fBFunction\fR \fBDescription\fR
+tigetflag get boolean entry for given \fIid\fP
+tigetnum get numeric entry for given \fIid\fP
+tigetstr get string entry for given \fIid\fP
+.TE
+.PP
+SVr3 also replaced several of the SVr2 terminfo functions
+which had no counterpart in the termcap interface,
+documenting them as obsolete:
+.TS
+l l
+_ _
+l l.
+\fBFunction\fR \fBReplaced by\fP
+crmode cbreak
+fixterm reset_prog_mode
+gettmode N/A
+nocrmode nocbreak
+resetterm reset_shell_mode
+saveterm def_prog_mode
+setterm setupterm
+.TE
+.PP
+SVr3 kept the \fBmvcur\fP, \fBvidattr\fP and \fBvidputs\fP functions,
+along with \fBputp\fP, \fBtparm\fP and \fBtputs\fP.
+The latter were needed to support padding,
+and handling functions such as \fBvidattr\fP
+(which used more than the two parameters supported by \fBtgoto\fP).
+.PP
+SVr3 introduced the functions for switching between terminal
+descriptions, e.g., \fBset_curterm\fP.
+The various global variables such as \fBboolnames\fP were mentioned
+in the programming manual at this point.
+.PP
+SVr4 added the \fBvid_attr\fP and \fBvid_puts\fP functions.
+.PP
+There are other low-level functions declared in the curses header files
+on Unix systems,
+but none were documented.
+The functions marked \*(``obsolete\*('' remained in use
+by the Unix \fBvi\fP editor.
.SH PORTABILITY
.SS Legacy functions
.PP
\fBint (*putc)(char)\fR.
.PP
At least one implementation of X/Open Curses (Solaris) returns a value
-other than OK/ERR from \fBtputs\fP.
+other than \fBOK\fP/\fBERR\fP from \fBtputs\fP.
That returns the length of the string, and does no error-checking.
.PP
X/Open notes that after calling \fBmvcur\fR, the curses state may not match the