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- * @Id: curs_getstr.3x,v 1.19 2010/12/04 18:36:44 tom Exp @
+ * @Id: curs_getstr.3x,v 1.33 2021/05/22 21:36:35 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
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-<H1>curs_getstr 3x</H1>
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+<H1 class="no-header">curs_getstr 3X</H1>
<PRE>
-<!-- Manpage converted by man2html 3.0.1 -->
-<STRONG><A HREF="curs_getstr.3x.html">curs_getstr(3x)</A></STRONG> <STRONG><A HREF="curs_getstr.3x.html">curs_getstr(3x)</A></STRONG>
+<B><A HREF="curs_getstr.3X.html">curs_getstr(3X)</A></B> <B><A HREF="curs_getstr.3X.html">curs_getstr(3X)</A></B>
-</PRE>
-<H2>NAME</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>
+ <B>getstr</B>, <B>getnstr</B>, <B>wgetstr</B>, <B>wgetnstr</B>, <B>mvgetstr</B>, <B>mvgetnstr</B>, <B>mvwgetstr</B>,
+ <B>mvwgetnstr</B> - accept character strings from <B>curses</B> terminal keyboard
-</PRE>
-<H2>SYNOPSIS</H2><PRE>
- <STRONG>#include</STRONG> <STRONG><curses.h></STRONG>
+</PRE><H2><a name="h2-SYNOPSIS">SYNOPSIS</a></H2><PRE>
+ <B>#include</B> <B><curses.h></B>
- <STRONG>int</STRONG> <STRONG>getstr(char</STRONG> <STRONG>*str);</STRONG>
- <STRONG>int</STRONG> <STRONG>getnstr(char</STRONG> <STRONG>*str,</STRONG> <STRONG>int</STRONG> <STRONG>n);</STRONG>
- <STRONG>int</STRONG> <STRONG>wgetstr(WINDOW</STRONG> <STRONG>*win,</STRONG> <STRONG>char</STRONG> <STRONG>*str);</STRONG>
- <STRONG>int</STRONG> <STRONG>wgetnstr(WINDOW</STRONG> <STRONG>*win,</STRONG> <STRONG>char</STRONG> <STRONG>*str,</STRONG> <STRONG>int</STRONG> <STRONG>n);</STRONG>
- <STRONG>int</STRONG> <STRONG>mvgetstr(int</STRONG> <STRONG>y,</STRONG> <STRONG>int</STRONG> <STRONG>x,</STRONG> <STRONG>char</STRONG> <STRONG>*str);</STRONG>
- <STRONG>int</STRONG> <STRONG>mvwgetstr(WINDOW</STRONG> <STRONG>*win,</STRONG> <STRONG>int</STRONG> <STRONG>y,</STRONG> <STRONG>int</STRONG> <STRONG>x,</STRONG> <STRONG>char</STRONG> <STRONG>*str);</STRONG>
- <STRONG>int</STRONG> <STRONG>mvgetnstr(int</STRONG> <STRONG>y,</STRONG> <STRONG>int</STRONG> <STRONG>x,</STRONG> <STRONG>char</STRONG> <STRONG>*str,</STRONG> <STRONG>int</STRONG> <STRONG>n);</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>
+ <B>int</B> <B>getstr(char</B> <B>*</B><I>str</I><B>);</B>
+ <B>int</B> <B>getnstr(char</B> <B>*</B><I>str</I><B>,</B> <B>int</B> <I>n</I><B>);</B>
+ <B>int</B> <B>wgetstr(WINDOW</B> <B>*</B><I>win</I><B>,</B> <B>char</B> <B>*</B><I>str</I><B>);</B>
+ <B>int</B> <B>wgetnstr(WINDOW</B> <B>*</B><I>win</I><B>,</B> <B>char</B> <B>*</B><I>str</I><B>,</B> <B>int</B> <I>n</I><B>);</B>
+ <B>int</B> <B>mvgetstr(int</B> <I>y</I><B>,</B> <B>int</B> <I>x</I><B>,</B> <B>char</B> <B>*</B><I>str</I><B>);</B>
+ <B>int</B> <B>mvwgetstr(WINDOW</B> <B>*</B><I>win</I><B>,</B> <B>int</B> <I>y</I><B>,</B> <B>int</B> <I>x</I><B>,</B> <B>char</B> <B>*</B><I>str</I><B>);</B>
+ <B>int</B> <B>mvgetnstr(int</B> <I>y</I><B>,</B> <B>int</B> <I>x</I><B>,</B> <B>char</B> <B>*</B><I>str</I><B>,</B> <B>int</B> <I>n</I><B>);</B>
+ <B>int</B> <B>mvwgetnstr(WINDOW</B> <B>*</B><I>win</I><B>,</B> <B>int</B> <I>y</I><B>,</B> <B>int</B> <I>x</I><B>,</B> <B>char</B> <B>*</B><I>str</I><B>,</B> <B>int</B> <I>n</I><B>);</B>
-</PRE>
-<H2>DESCRIPTION</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 <B>getstr</B> is equivalent to a series of calls to <B>getch</B>, 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 <I>str</I>, followed by a NUL.
-</PRE>
-<H2>RETURN VALUE</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.
+ The <B>getnstr</B> function reads from the <I>stdscr</I> default window. The other
+ functions, such as <B>wgetnstr</B>, read from the window given as a parameter.
+
+ <B>getnstr</B> reads at most <I>n</I> characters, thus preventing a possible overflow
+ of the input buffer. Any attempt to enter more characters (other than
+ the terminating newline or carriage return) causes a beep. Function
+ keys also cause a beep and are ignored.
+
+ The user's <I>erase</I> and <I>kill</I> characters are interpreted:
+
+ <B>o</B> The <I>erase</I> character (e.g., <B>^H</B>) erases the character at the end of
+ the buffer, moving the cursor to the left.
+
+ If <I>keypad</I> mode is on for the window, <B>KEY_LEFT</B> and <B>KEY_BACKSPACE</B> are
+ both considered equivalent to the user's erase character.
+
+ <B>o</B> The <I>kill</I> character (e.g., <B>^U</B>) erases the entire buffer, leaving the
+ cursor at the beginning of the buffer.
+
+ Characters input are echoed only if <B>echo</B> 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 <B>ERR</B> upon failure and an <B>OK</B> (SVr4 speci-
+ fies only "an integer value other than <B>ERR</B>") 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 <B>SIGWINCH</B> in-
+ terrupts the function, it will return <B>KEY_RESIZE</B> rather than <B>OK</B> or <B>ERR</B>.
- 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
+ <B>wmove</B>, and return an error if the position is outside the window, or if
+ the window pointer is null.
-</PRE>
-<H2>NOTES</H2><PRE>
- Note that <STRONG>getstr</STRONG>, <STRONG>mvgetstr</STRONG>, and <STRONG>mvwgetstr</STRONG> may be macros.
+</PRE><H2><a name="h2-NOTES">NOTES</a></H2><PRE>
+ Note that <B>getstr</B>, <B>mvgetstr</B>, and <B>mvwgetstr</B> may be macros.
-</PRE>
-<H2>PORTABILITY</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 <B>ERR</B> if the window
+ pointer is null, or if the lower-level <B><A HREF="curs_getch.3X.html">wgetch(3X)</A></B> call returns an <B>ERR</B>.
+ 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, <I>etc</I>.) 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>SEE ALSO</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>.
+ The functions <B>getnstr</B>, <B>mvgetnstr</B>, and <B>mvwgetnstr</B> were present but not
+ documented in SVr4.
+
+ X/Open Curses, Issue 5 (2007) stated that these functions "read at most
+ <I>n</I> 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 <I>n</I>-1 bytes" to allow for the terminating NUL. As of 2018,
+ some implementations do, some do not count it:
+
+ <B>o</B> ncurses 6.1 and PDCurses do not count the NUL in the given limit,
+ while
+
+ <B>o</B> Solaris SVr4 and NetBSD curses count the NUL as part of the limit.
+
+ <B>o</B> Solaris xcurses provides both: its wide-character <B>wget_nstr</B> re-
+ serves a NUL, but its <B>wgetnstr</B> does not count the NUL consistently.
+
+ In SVr4 curses, a negative value of <I>n</I> tells <B>wgetnstr</B> to assume that the
+ caller's buffer is large enough to hold the result, i.e., to act like
+ <B>wgetstr</B>. X/Open Curses does not mention this (or anything related to
+ negative or zero values of <I>n</I>), however most implementations use the
+ feature, with different limits:
+
+ <B>o</B> Solaris SVr4 curses and PDCurses limit the result to 255 bytes.
+ Other Unix systems than Solaris are likely to use the same limit.
+
+ <B>o</B> Solaris xcurses limits the result to <B>LINE_MAX</B> bytes.
+
+ <B>o</B> NetBSD 7 assumes no particular limit for the result from <B>wgetstr</B>.
+ However, it limits the <B>wgetnstr</B> parameter <I>n</I> to ensure that it is
+ greater than zero.
+
+ A comment in NetBSD's source code states that this is specified in
+ SUSv2.
+
+ <B>o</B> ncurses (before 6.2) assumes no particular limit for the result
+ from <B>wgetstr</B>, and treats the <I>n</I> parameter of <B>wgetnstr</B> like SVr4
+ curses.
+
+ <B>o</B> ncurses 6.2 uses <B>LINE_MAX</B>, or a larger (system-dependent) value
+ which the <B>sysconf</B> function may provide. If neither <B>LINE_MAX</B> or
+ <B>sysconf</B> is available, ncurses uses the POSIX value for <B>LINE_MAX</B> (a
+ 2048 byte limit). In either case, it reserves a byte for the ter-
+ minating NUL.
+
+ Although <B>getnstr</B> is equivalent to a series of calls to <B>getch</B>, it also
+ makes changes to the curses modes to allow simple editing of the input
+ buffer:
+
+ <B>o</B> <B>getnstr</B> saves the current value of the <B>nl</B>, <B>echo</B>, <B>raw</B> and <B>cbreak</B>
+ modes, and sets <B>nl</B>, <B>noecho</B>, <B>noraw</B>, and <B>cbreak</B>.
+
+ <B>getnstr</B> handles the echoing of characters, rather than relying on
+ the caller to set an appropriate mode.
+
+ <B>o</B> It also obtains the <I>erase</I> and <I>kill</I> characters from <B>erasechar</B> and
+ <B>killchar</B>, respectively.
+
+ <B>o</B> On return, <B>getnstr</B> restores the modes to their previous values.
+
+ Other implementations differ in their treatment of special characters:
+
+ <B>o</B> While they may set the <I>echo</I> mode, other implementations do not mod-
+ ify the <I>raw</I> mode, They may take the <I>cbreak</I> mode set by the caller
+ into account when deciding whether to handle echoing within <B>getnstr</B>
+ or as a side-effect of the <B>getch</B> calls.
+
+ <B>o</B> The original ncurses (as pcurses in 1986) set <B>noraw</B> and <B>cbreak</B> when
+ accepting input for <B>getnstr</B>. That may have been done to make func-
+ tion- and cursor-keys work; it is not necessary with ncurses.
+
+ Since 1995, ncurses has provided signal handlers for INTR and QUIT
+ (e.g., <B>^C</B> or <B>^\</B>). With the <B>noraw</B> and <B>cbreak</B> settings, those may
+ catch a signal and stop the program, where other implementations
+ allow one to enter those characters in the buffer.
+
+ <B>o</B> Starting in 2021 (ncurses 6.3), <B>getnstr</B> sets <B>raw</B>, rather than <B>noraw</B>
+ and <B>cbreak</B> for better compatibility with SVr4-curses, e.g., allow-
+ ing one to enter a <B>^C</B> into the buffer.
+
+
+</PRE><H2><a name="h2-SEE-ALSO">SEE ALSO</a></H2><PRE>
+ <B><A HREF="curses.3X.html">curses(3X)</A></B>, <B><A HREF="curs_getch.3X.html">curs_getch(3X)</A></B>, <B><A HREF="curs_termattrs.3X.html">curs_termattrs(3X)</A></B>, <B><A HREF="curs_variables.3X.html">curs_variables(3X)</A></B>.
- <STRONG><A HREF="curs_getstr.3x.html">curs_getstr(3x)</A></STRONG>
+ <B><A HREF="curs_getstr.3X.html">curs_getstr(3X)</A></B>
</PRE>
-<HR>
-<ADDRESS>
-Man(1) output converted with
-<a href="http://www.oac.uci.edu/indiv/ehood/man2html.html">man2html</a>
-</ADDRESS>
+<div class="nav">
+<ul>
+<li><a href="#h2-NAME">NAME</a></li>
+<li><a href="#h2-SYNOPSIS">SYNOPSIS</a></li>
+<li><a href="#h2-DESCRIPTION">DESCRIPTION</a></li>
+<li><a href="#h2-RETURN-VALUE">RETURN VALUE</a></li>
+<li><a href="#h2-NOTES">NOTES</a></li>
+<li><a href="#h2-PORTABILITY">PORTABILITY</a></li>
+<li><a href="#h2-SEE-ALSO">SEE ALSO</a></li>
+</ul>
+</div>
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