.\"***************************************************************************
-.\" Copyright (c) 2002-2010,2012 Free Software Foundation, Inc. *
+.\" Copyright 2018-2019,2020 Thomas E. Dickey *
+.\" Copyright 2002-2012,2017 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_get_wstr.3x,v 1.9 2012/11/03 23:03:59 tom Exp $
+.\" $Id: curs_get_wstr.3x,v 1.21 2020/10/17 23:17:24 tom Exp $
.TH curs_get_wstr 3X ""
+.ie \n(.g .ds `` \(lq
+.el .ds `` ``
+.ie \n(.g .ds '' \(rq
+.el .ds '' ''
+.de bP
+.ie n .IP \(bu 4
+.el .IP \(bu 2
+..
.na
.hy 0
.SH NAME
\fBint wget_wstr(WINDOW *\fR\fIwin\fR\fB, wint_t *\fR\fIwstr\fR\fB);\fR
.br
\fBint wgetn_wstr(WINDOW *\fR\fIwin\fR\fB, wint_t *\fR\fIwstr\fR\fB, int \fR\fIn\fR\fB);\fR
-.br
+.sp
\fBint mvget_wstr(int \fR\fIy\fR\fB, int \fR\fIx\fR\fB, wint_t *\fR\fIwstr\fR\fB);\fR
.br
\fBint mvgetn_wstr(int \fR\fIy\fR\fB, int \fR\fIx\fR\fB, wint_t *\fR\fIwstr\fR\fB, int \fR\fIn\fR\fB);\fR
\fBget_wstr\fR
is as though a series of calls
to
-\fBget_wch\fR
-were made, until a newline, other end-of-line, or end-of-file condition is processed.
-An end-of-file condition is represented by \fBWEOF\fR, as defined in \fB<wchar.h>\fR.
-The newline and end-of-line conditions are represented by the \fB\\n\fR \fBwchar_t\fR value.
+\fBget_wch\fR(3X)
+were made, until a newline, other end-of-line,
+or end-of-file condition is processed.
+An end-of-file condition is represented by \fBWEOF\fR,
+as defined in \fB<wchar.h>\fR.
+The newline and end-of-line conditions are represented
+by the \fB\\n\fR \fBwchar_t\fR value.
In all instances, the end of the string is terminated by a null \fBwchar_t\fR.
The routine places resulting values in the area pointed to by \fIwstr\fR.
.PP
-The user's erase and kill characters are interpreted. If keypad
+The user's erase and kill characters are interpreted.
+If keypad
mode is on for the window, \fBKEY_LEFT\fR and \fBKEY_BACKSPACE\fR
are both considered equivalent to the user's kill character.
.PP
-Characters input are echoed only if \fBecho\fR is currently on. In that case,
+Characters input are echoed only if \fBecho\fR is currently on.
+In that case,
backspace is echoed as deletion of the previous character (typically a left
motion).
.PP
returns an error if the associated call to \fBwget_wch\fP failed.
.RE
.PP
-Functions with a "mv" prefix first perform a cursor movement using
+Functions with a \*(``mv\*('' prefix first perform a cursor movement using
\fBwmove\fP, and return an error if the position is outside the window,
or if the window pointer is null.
.SH PORTABILITY
These functions are described in The Single Unix Specification, Version 2.
No error conditions are defined.
-This implementation returns ERR if the window pointer is null,
-or if the lower-level \fBwget_wch\fR call returns an ERR.
+This implementation returns \fBERR\fP if the window pointer is null,
+or if the lower-level \fBwget_wch\fR call returns an \fBERR\fP.
In the latter case,
-an ERR return without other data is treated as an end-of-file condition,
+an \fBERR\fP return without other data is treated as an end-of-file condition,
and the returned array contains a \fBWEOF\fR followed by a null \fBwchar_t\fR.
.PP
-X/Open curses documents these functions to pass an array of \fBwchar_t\fR,
-but all of the vendors implement this using \fBwint_t\fR.
+X/Open curses documented these functions to pass an array of \fBwchar_t\fR
+in 1997, but that was an error because of this part of the description:
+.RS
+.PP
+The effect of \fIget_wstr()\fP is as though a series of calls to
+\fIget_wch()\fP were made, until a newline character, end-of-line character, or
+end-of-file character is processed.
+.RE
+.PP
+The latter function \fIget_wch()\fP can return a negative value,
+while \fBwchar_t\fP is a unsigned type.
+All of the vendors implement this using \fBwint_t\fR, following the standard.
+.PP
+X/Open Curses, Issue 7 (2009) is unclear regarding whether
+the terminating \fInull \fP\fBwchar_t\fP
+value is counted in the length parameter \fIn\fP.
+X/Open Curses, Issue 7 revised the corresponding description
+of \fBwgetnstr\fP to address this issue.
+The unrevised description of \fBwget_nwstr\fP can be interpreted either way.
+This implementation counts the terminator in the length.
+.PP
+X/Open Curses does not specify what happens if the length \fIn\fP is negative.
+.bP
+For analogy with \fBwgetnstr\fP,
+ncurses 6.2 uses a limit (based on \fBLINE_MAX\fP).
+.bP
+Some other implementations (such as Solaris xcurses) do the same,
+while others (PDCurses) do not allow this.
+.bP
+NetBSD 7 curses imitates ncurses 6.1 in this regard,
+treating a \fB\-1\fP as an indefinite number of characters.
.SH SEE ALSO
Functions:
\fBcurses\fR(3X),
projects / ncurses.git / blobdiff