.\"***************************************************************************
-.\" Copyright (c) 2002-2012,2017 Free Software Foundation, Inc. *
+.\" Copyright 2018-2022,2023 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 1.10 2017/01/07 19:25:15 tom Exp $
-.TH curs_get_wstr 3X ""
-.na
-.hy 0
+.\" $Id: curs_get_wstr.3x,v 1.34 2023/09/16 23:34:43 tom Exp $
+.TH curs_get_wstr 3X 2023-09-16 "ncurses 6.4" "Library calls"
+.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
+..
.SH NAME
-\fBget_wstr\fR,
-\fBgetn_wstr\fR,
-\fBwget_wstr\fR,
-\fBwgetn_wstr\fR,
-\fBmvget_wstr\fR,
-\fBmvgetn_wstr\fR,
-\fBmvwget_wstr\fR,
-\fBmvwgetn_wstr\fR \- get an array of wide characters from a curses terminal keyboard
-.ad
-.hy
+\fB\%get_wstr\fP,
+\fB\%getn_wstr\fP,
+\fB\%wget_wstr\fP,
+\fB\%wgetn_wstr\fP,
+\fB\%mvget_wstr\fP,
+\fB\%mvgetn_wstr\fP,
+\fB\%mvwget_wstr\fP,
+\fB\%mvwgetn_wstr\fP \-
+get a wide-character string from a \fIcurses\fR terminal keyboard
.SH SYNOPSIS
.nf
-\fB#include <curses.h>\fR
+\fB#include <curses.h>\fP
.sp
-\fBint get_wstr(wint_t *\fR\fIwstr\fR\fB);\fR
+\fBint get_wstr(wint_t *\fIwstr\fB);\fR
.br
-\fBint getn_wstr(wint_t *\fR\fIwstr\fR\fB, int \fR\fIn\fR\fB);\fR
+\fBint getn_wstr(wint_t *\fIwstr\fB, int \fIn\fB);\fR
.br
-\fBint wget_wstr(WINDOW *\fR\fIwin\fR\fB, wint_t *\fR\fIwstr\fR\fB);\fR
+\fBint wget_wstr(WINDOW *\fIwin\fB, wint_t *\fIwstr\fB);\fR
.br
-\fBint wgetn_wstr(WINDOW *\fR\fIwin\fR\fB, wint_t *\fR\fIwstr\fR\fB, int \fR\fIn\fR\fB);\fR
-.br
-\fBint mvget_wstr(int \fR\fIy\fR\fB, int \fR\fIx\fR\fB, wint_t *\fR\fIwstr\fR\fB);\fR
+\fBint wgetn_wstr(WINDOW *\fIwin\fB, wint_t *\fIwstr\fB, int \fIn\fB);\fR
+.sp
+\fBint mvget_wstr(int \fIy\fB, int \fIx\fB, wint_t *\fIwstr\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
+\fBint mvgetn_wstr(int \fIy\fB, int \fIx\fB, wint_t *\fIwstr\fB, int \fIn\fB);\fR
.br
-\fBint mvwget_wstr(WINDOW *\fR\fIwin\fR\fB, int \fR\fIy\fR\fB, int \fR\fIx\fR\fB, wint_t *\fR\fIwstr\fR\fB);\fR
+\fBint mvwget_wstr(WINDOW *\fIwin\fB, int \fIy\fB, int \fIx\fB, wint_t *\fIwstr\fB);\fR
.br
-\fBint mvwgetn_wstr(WINDOW *\fR\fIwin\fR\fB, int \fR\fIy\fR\fB, int \fR\fIx\fR\fB, wint_t *\fR\fIwstr\fR\fB, int \fR\fIn\fR\fB);\fR
+\fBint mvwgetn_wstr(WINDOW *\fIwin\fB, int \fIy\fB, int \fIx\fB, wint_t *\fIwstr\fB, int \fIn\fB);\fR
.fi
.SH DESCRIPTION
-The effect of
-\fBget_wstr\fR
-is as though a series of calls
-to
-\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
-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,
-backspace is echoed as deletion of the previous character (typically a left
-motion).
-.PP
-The effect of
-\fBwget_wstr\fR
-is as though a series of
-calls to
-\fBwget_wch\fR
-were made.
+The function
+\fBwgetn_wstr\fP
+is equivalent to a series of calls to
+\fBwget_wch\fP(3X)
+until a newline or carriage return terminates the series:
+.bP
+The terminating character is not included in the returned string.
+.bP
+An end-of-file condition is represented by \fBWEOF\fP,
+as defined in \fB<wchar.h>\fP.
+.bP
+In all instances, the end of the string is terminated
+by a null \fBwchar_t\fP.
+.bP
+The function stores the result in the area pointed to
+by the \fIwstr\fP parameter.
+.bP
+The function reads at most \fIn\fP characters,
+thus preventing a possible overflow of the input buffer.
+.IP
+Any attempt to enter more characters
+(other than the terminating newline or carriage return)
+causes a beep.
+.IP
+Function keys also cause a beep and are ignored.
.PP
-The effect of
-\fBmvget_wstr\fR
-is as though a call to
-\fBmove\fR
-and then a series of calls to
-\fBget_wch\fR
-were
-made.
+The user's \fIerase\fP and \fIkill\fP characters are interpreted:
+.bP
+The \fIerase\fP character (e.g., \fB^H\fP) erases the character
+at the end of the buffer, moving the cursor to the left.
+.IP
+If \fIkeypad\fP mode is on for the window,
+\fBKEY_LEFT\fP and \fBKEY_BACKSPACE\fP
+are both considered equivalent to the user's \fIerase\fP character.
+.bP
+The \fIkill\fP character (e.g., \fB^U\fP) erases the entire buffer,
+leaving the cursor at the beginning of the buffer.
.PP
-The effect of
-\fBmvwget_wstr\fR
-is as though a call to
-\fBwmove\fR
-and then a series of calls to
-\fBwget_wch\fR
-were made.
+Characters input are echoed only if \fBecho\fP is currently on.
+In that case,
+backspace is echoed as deletion of the previous character
+(typically a left motion).
.PP
The
-\fBgetn_wstr\fR,
-\fBmvgetn_wstr\fR,
-\fBmvwgetn_wstr\fR, and
-\fBwgetn_wstr\fR
+\fBgetn_wstr\fP,
+\fBmvgetn_wstr\fP,
+\fBmvwgetn_wstr\fP, and
+\fBwgetn_wstr\fP
functions are identical
to the
-\fBget_wstr\fR,
-\fBmvget_wstr\fR,
-\fBmvwget_wstr\fR, and
-\fBwget_wstr\fR
+\fBget_wstr\fP,
+\fBmvget_wstr\fP,
+\fBmvwget_wstr\fP, and
+\fBwget_wstr\fP
functions, respectively,
except that the
-\fB*n_*\fR
+\fB*n_*\fP
versions read at most
-\fIn\fR
+\fIn\fP
characters, letting the application prevent overflow of the
input buffer.
.SH NOTES
+Any of these functions other than
+\fBwgetn_wstr\fP
+may be macros.
+.PP
Using
-\fBget_wstr\fR,
-\fBmvget_wstr\fR,
-\fBmvwget_wstr\fR, or
-\fBwget_wstr\fR
+\fBget_wstr\fP,
+\fBmvget_wstr\fP,
+\fBmvwget_wstr\fP, or
+\fBwget_wstr\fP
to read a line that
overflows the array pointed to by
-\fBwstr\fR
+\fBwstr\fP
causes undefined
results.
The use of
-\fBgetn_wstr\fR,
-\fBmvgetn_wstr\fR,
-\fBmvwgetn_wstr\fR, or
-\fBwgetn_wstr\fR, respectively, is recommended.
+\fBgetn_wstr\fP,
+\fBmvgetn_wstr\fP,
+\fBmvwgetn_wstr\fP, or
+\fBwgetn_wstr\fP,
+respectively, is recommended.
.PP
-These functions cannot return \fBKEY_\fR values because there
-is no way to distinguish a \fBKEY_\fR value from a valid \fBwchar_t\fR value.
-.PP
-All of these routines except \fBwgetn_wstr\fR may be macros.
+These functions cannot return \fBKEY_\fP values because there
+is no way to distinguish a \fBKEY_\fP value from a valid \fBwchar_t\fP value.
+may be macros.
.SH RETURN VALUE
-All of these functions return \fBOK\fR upon successful completion.
-Otherwise, they return \fBERR\fR.
+All of these functions return the integer \fBOK\fP upon successful completion.
+If unsuccessful, they return \fBERR\fP.
.PP
-Functions using a window parameter return an error if it is null.
-.RS
-.TP 5
-\fBwgetn_wstr\fP
-returns an error if the associated call to \fBwget_wch\fP failed.
-.RE
+X/Open defines no error conditions.
+.PP
+In this implementation,
+these functions return an error
+.bP
+if the window pointer is null,
+.bP
+if its timeout expires without having any data, or
+.bP
+if the associated call to
+\fBwget_wch\fP
+failed.
.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.
+.PP
+This implementation returns \fBERR\fP if the window pointer is null,
+or if the lower-level \fBwget_wch\fP call returns an \fBERR\fP.
In the latter case,
-an ERR 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.
+an \fBERR\fP return without other data is treated as an end-of-file condition,
+and the returned array contains a \fBWEOF\fP followed by a null \fBwchar_t\fP.
+.PP
+X/Open curses documented these functions to pass an array of \fBwchar_t\fP
+in 1997, but that was an error because of this part of the description:
+.RS
+.PP
+The effect of \fBget_wstr\fP is as though a series of calls to
+\fBget_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\fP, following the standard.
+.PP
+X/Open Curses, Issue 7 (2009) is unclear regarding whether
+the terminating \fInull \fBwchar_t\fR
+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 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 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),
-\fBcurs_get_wch\fR(3X),
-\fBcurs_getstr\fR(3X).
+\fBcurses\fP(3X),
+\fBcurs_get_wch\fP(3X),
+\fBcurs_getstr\fP(3X).
projects / ncurses.git / blobdiff