<!--
****************************************************************************
- * Copyright (c) 1998-2005,2010 Free Software Foundation, Inc. *
+ * Copyright (c) 1998-2017,2018 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 *
* sale, use or other dealings in this Software without prior written *
* authorization. *
****************************************************************************
- * @Id: curs_getstr.3x,v 1.19 2010/12/04 18:36:44 tom Exp @
+ * @Id: curs_getstr.3x,v 1.26 2018/09/01 20:34:52 tom Exp @
+ * X/Open says also until EOf
+ * X/Open says then an EOS is added to the result
+ * X/Open doesn't mention n<0
-->
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01//EN">
<HTML>
<HEAD>
<meta http-equiv="Content-Type" content="text/html; charset=us-ascii">
-<meta name="generator" content="Manpage converted by man2html - see http://invisible-island.net/scripts/readme.html#others_scripts">
+<meta name="generator" content="Manpage converted by man2html - see https://invisible-island.net/scripts/readme.html#others_scripts">
<TITLE>curs_getstr 3x</TITLE>
-<link rev=made href="mailto:bug-ncurses@gnu.org">
+<link rel="author" href="mailto:bug-ncurses@gnu.org">
<meta http-equiv="Content-Type" content="text/html; charset=iso-8859-1">
</HEAD>
<BODY>
<H1 class="no-header">curs_getstr 3x</H1>
<PRE>
-<STRONG><A HREF="curs_getstr.3x.html">curs_getstr(3x)</A></STRONG> <STRONG><A HREF="curs_getstr.3x.html">curs_getstr(3x)</A></STRONG>
+<STRONG><A HREF="curs_getstr.3x.html">curs_getstr(3x)</A></STRONG>
<STRONG><A HREF="curs_getstr.3x.html">curs_getstr(3x)</A></STRONG>
-</PRE>
-<H2><a name="h2-NAME">NAME</a></H2><PRE>
- <STRONG>getstr</STRONG>, <STRONG>getnstr</STRONG>, <STRONG>wgetstr</STRONG>, <STRONG>wgetnstr</STRONG>, <STRONG>mvgetstr</STRONG>, <STRONG>mvgetnstr</STRONG>,
- <STRONG>mvwgetstr</STRONG>, <STRONG>mvwgetnstr</STRONG> - accept character strings from
- <STRONG>curses</STRONG> terminal keyboard
+</PRE><H2><a name="h2-NAME">NAME</a></H2><PRE>
+ <STRONG>getstr</STRONG>, <STRONG>getnstr</STRONG>, <STRONG>wgetstr</STRONG>, <STRONG>wgetnstr</STRONG>, <STRONG>mvgetstr</STRONG>, <STRONG>mvgetnstr</STRONG>, <STRONG>mvwgetstr</STRONG>,
+ <STRONG>mvwgetnstr</STRONG> - accept character strings from <STRONG>curses</STRONG> terminal keyboard
-</PRE>
-<H2><a name="h2-SYNOPSIS">SYNOPSIS</a></H2><PRE>
+</PRE><H2><a name="h2-SYNOPSIS">SYNOPSIS</a></H2><PRE>
<STRONG>#include</STRONG> <STRONG><curses.h></STRONG>
<STRONG>int</STRONG> <STRONG>getstr(char</STRONG> <STRONG>*str);</STRONG>
<STRONG>int</STRONG> <STRONG>mvwgetnstr(WINDOW</STRONG> <STRONG>*,</STRONG> <STRONG>int</STRONG> <STRONG>y,</STRONG> <STRONG>int</STRONG> <STRONG>x,</STRONG> <STRONG>char</STRONG> <STRONG>*str,</STRONG> <STRONG>int</STRONG> <STRONG>n);</STRONG>
-</PRE>
-<H2><a name="h2-DESCRIPTION">DESCRIPTION</a></H2><PRE>
- The function <STRONG>getstr</STRONG> is equivalent to a series of calls to
- <STRONG>getch</STRONG>, until a newline or carriage return is received (the
- terminating character is not included in the returned
- string). The resulting value is placed in the area point-
- ed to by the character pointer <EM>str</EM>.
-
- <STRONG>wgetnstr</STRONG> reads at most <EM>n</EM> characters, thus preventing a
- possible overflow of the input buffer. Any attempt to en-
- ter more characters (other than the terminating newline or
- carriage return) causes a beep. Function keys also cause
- a beep and are ignored. The <STRONG>getnstr</STRONG> function reads from
- the <EM>stdscr</EM> default window.
-
- The user's erase and kill characters are interpreted. If
- keypad mode is on for the window, <STRONG>KEY_LEFT</STRONG> and
- <STRONG>KEY_BACKSPACE</STRONG> are both considered equivalent to the user's
- kill character.
-
- Characters input are echoed only if <STRONG>echo</STRONG> is currently on.
- In that case, backspace is echoed as deletion of the pre-
- vious character (typically a left motion).
+</PRE><H2><a name="h2-DESCRIPTION">DESCRIPTION</a></H2><PRE>
+ The function <STRONG>getstr</STRONG> is equivalent to a series of calls to <STRONG>getch</STRONG>, until
+ a newline or carriage return is received (the terminating character is
+ not included in the returned string). The resulting value is placed in
+ the area pointed to by the character pointer <EM>str</EM>, followed by a NUL.
+ <STRONG>wgetnstr</STRONG> reads at most <EM>n</EM> characters, thus preventing a possible over-
+ flow of the input buffer. Any attempt to enter more characters (other
+ than the terminating newline or carriage return) causes a beep. Func-
+ tion keys also cause a beep and are ignored. The <STRONG>getnstr</STRONG> function
+ reads from the <EM>stdscr</EM> default window.
+
+ The user's erase and kill characters are interpreted. If keypad mode
+ is on for the window, <STRONG>KEY_LEFT</STRONG> and <STRONG>KEY_BACKSPACE</STRONG> are both considered
+ equivalent to the user's kill character.
+
+ Characters input are echoed only if <STRONG>echo</STRONG> is currently on. In that
+ case, backspace is echoed as deletion of the previous character (typi-
+ cally a left motion).
-</PRE>
-<H2><a name="h2-RETURN-VALUE">RETURN VALUE</a></H2><PRE>
- All routines return the integer <STRONG>ERR</STRONG> upon failure and an <STRONG>OK</STRONG>
- (SVr4 specifies only "an integer value other than <STRONG>ERR</STRONG>")
- upon successful completion.
+
+<
/PRE><H2><a name="h2-RETURN-VALUE">RETURN VALUE</a></H2><PRE>
+ All routines return the integer <STRONG>ERR</STRONG> upon failure and an <STRONG>OK</STRONG> (SVr4 speci-
+ fies only "an integer value other than <STRONG>ERR</STRONG>") upon successful comple-
+ tion.
X/Open defines no error conditions.
- In this implementation, these functions return an error if
- the window pointer is null, or if its timeout expires
- without having any data.
+ In this implementation, these functions return an error if the window
+ pointer is null, or if its timeout expires without having any data.
- This implementation provides an extension as well. If a
- SIGWINCH interrupts the function, it will return <STRONG>KEY_RE-</STRONG>
- <STRONG>SIZE</STRONG> rather than <STRONG>OK</STRONG> or <STRONG>ERR</STRONG>.
+ This implementation provides an extension as well. If a <STRONG>SIGWINCH</STRONG> in-
+ terrupts the function, it will return <STRONG>KEY_RESIZE</STRONG> rather than <STRONG>OK</STRONG> or <STRONG>ERR</STRONG>.
- Functions with a "mv" prefix first perform a cursor move-
- ment using <STRONG>wmove</STRONG>, and return an error if the position is
- outside the window, or if the window pointer is null.
+ Functions with a "mv" prefix first perform a cursor movement using
+ <STRONG>wmove</STRONG>, and return an error if the position is outside the window, or if
+ the window pointer is null.
-</PRE>
-<H2><a name="h2-NOTES">NOTES</a></H2><PRE>
+</PRE><H2><a name="h2-NOTES">NOTES</a></H2><PRE>
Note that <STRONG>getstr</STRONG>, <STRONG>mvgetstr</STRONG>, and <STRONG>mvwgetstr</STRONG> may be macros.
-</PRE>
-<H2><a name="h2-PORTABILITY">PORTABILITY</a></H2><PRE>
- These functions are described in the XSI Curses standard,
- Issue 4. They read single-byte characters only. The
- standard does not define any error conditions. This im-
- plementation returns ERR if the window pointer is null, or
- if the lower-level <STRONG>wgetch</STRONG> call returns an ERR.
-
- SVr3 and early SVr4 curses implementations did not reject
- function keys; the SVr4.0 documentation claimed that "spe-
- cial keys" (such as function keys, "home" key, "clear"
- key, <EM>etc</EM>.) are "interpreted", without giving details. It
- lied. In fact, the `character' value appended to the
- string by those implementations was predictable but not
- useful (being, in fact, the low-order eight bits of the
- key's KEY_ value).
-
- The functions <STRONG>getnstr</STRONG>, <STRONG>mvgetnstr</STRONG>, and <STRONG>mvwgetnstr</STRONG> were
- present but not documented in SVr4.
+</PRE><H2><a name="h2-PORTABILITY">PORTABILITY</a></H2><PRE>
+ These functions are described in the XSI Curses standard, Issue 4.
+ They read single-byte characters only. The standard does not define
+ any error conditions. This implementation returns <STRONG>ERR</STRONG> if the window
+ pointer is null, or if the lower-level <STRONG><A HREF="curs_getch.3x.html">wgetch(3x)</A></STRONG> call returns an <STRONG>ERR</STRONG>.
+ SVr3 and early SVr4 curses implementations did not reject function
+ keys; the SVr4.0 documentation claimed that "special keys" (such as
+ function keys, "home" key, "clear" key, <EM>etc</EM>.) are "interpreted", with-
+ out giving details. It lied. In fact, the "character" value appended
+ to the string by those implementations was predictable but not useful
+ (being, in fact, the low-order eight bits of the key's KEY_ value).
-</PRE>
-<H2><a name="h2-SEE-ALSO">SEE ALSO</a></H2><PRE>
+ The functions <STRONG>getnstr</STRONG>, <STRONG>mvgetnstr</STRONG>, and <STRONG>mvwgetnstr</STRONG> were present but not
+ documented in SVr4.
+
+ X/Open Curses issue 5 (2007) stated that these functions "read at most
+ <EM>n</EM> bytes" but did not state whether the terminating NUL is counted in
+ that limit. X/Open Curses issue 7 (2009) changed that to say they
+ "read at most <EM>n</EM>-1 bytes" to allow for the terminating NUL. As of 2018,
+ some implementations do, some do not count it:
+
+ <STRONG>o</STRONG> ncurses 6.1 and PDCurses do not count the NUL in the given limit,
+ while
+
+ <STRONG>o</STRONG> Solaris SVr4 and NetBSD curses count the NUL as part of the limit.
+
+ <STRONG>o</STRONG> Solaris xcurses provides both: its wide-character <STRONG>wget_nstr</STRONG> re-
+ serves a NUL, but its <STRONG>wgetnstr</STRONG> does not count the NUL consistently.
+
+ In SVr4 curses, a negative value of <EM>n</EM> tells <STRONG>wgetnstr</STRONG> to assume that the
+ caller's buffer is large enough to hold the result, i.e., to act like
+ <STRONG>wgetstr</STRONG>. X/Open Curses does not mention this (or anything related to
+ negative or zero values of <EM>n</EM>), however most implementations use the
+ feature, with different limits:
+
+ <STRONG>o</STRONG> Solaris SVr4 curses and PDCurses limit the result to 255 bytes.
+ Other Unix systems than Solaris are likely to use the same limit.
+
+ <STRONG>o</STRONG> Solaris xcurses limits the result to <STRONG>LINE_MAX</STRONG> bytes.
+
+ <STRONG>o</STRONG> NetBSD 7 assumes no particular limit for the result from <STRONG>wgetstr</STRONG>.
+ However, it limits the <STRONG>wgetnstr</STRONG> parameter <EM>n</EM> to ensure that it is
+ greater than zero.
+
+ A comment in NetBSD's source code states that this is specified in
+ SUSv2.
+
+ <STRONG>o</STRONG> ncurses (before 6.2) assumes no particular limit for the result
+ from <STRONG>wgetstr</STRONG>, and treats the <EM>n</EM> parameter of <STRONG>wgetnstr</STRONG> like SVr4
+ curses.
+
+ <STRONG>o</STRONG> ncurses 6.2 uses <STRONG>LINE_MAX</STRONG>, or a larger (system-dependent) value
+ which the <STRONG>sysconf</STRONG> function may provide. If neither <STRONG>LINE_MAX</STRONG> or
+ <STRONG>sysconf</STRONG> is available, ncurses uses the POSIX value for <STRONG>LINE_MAX</STRONG> (a
+ 2048 byte limit). In either case, it reserves a byte for the ter-
+ minating NUL.
+
+
+</PRE><H2><a name="h2-SEE-ALSO">SEE ALSO</a></H2><PRE>
<STRONG><A HREF="ncurses.3x.html">curses(3x)</A></STRONG>, <STRONG><A HREF="curs_getch.3x.html">curs_getch(3x)</A></STRONG>, <STRONG><A HREF="curs_variables.3x.html">curs_variables(3x)</A></STRONG>.
- <STRONG><A HREF="curs_getstr.3x.html">curs_getstr(3x)</A></STRONG>
+
<STRONG><A HREF="curs_getstr.3x.html">curs_getstr(3x)</A></STRONG>
</PRE>
<div class="nav">
<ul>
projects / ncurses.git / blobdiff