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- * @Id: curs_getstr.3x,v 1.42 2023/08/05 12:14:30 tom Exp @
+ * @Id: curs_getstr.3x,v 1.46 2023/09/16 23:34:43 tom Exp @
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-<H1 class="no-header">curs_getstr 3x 2023-08-05 ncurses 6.4 Library calls</H1>
+<H1 class="no-header">curs_getstr 3x 2023-09-16 ncurses 6.4 Library calls</H1>
<PRE>
<STRONG><A HREF="curs_getstr.3x.html">curs_getstr(3x)</A></STRONG> Library calls <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
+ <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 <EM>curses</EM> terminal keyboard
</PRE><H2><a name="h2-SYNOPSIS">SYNOPSIS</a></H2><PRE>
cursor at the beginning of the buffer.
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).
+ case, backspace is echoed as deletion of the previous character
+ (typically a left motion).
- The <STRONG>getnstr</STRONG>, <STRONG>mvgetnstr</STRONG>, <STRONG>mvwgetnstr</STRONG>, and <STRONG>wgetnstr</STRONG> functions are identi-
- cal to the <STRONG>getstr</STRONG>, <STRONG>mvgetstr</STRONG>, <STRONG>mvwgetstr</STRONG>, and <STRONG>wgetstr</STRONG> functions, respec-
- tively, except that the <STRONG>*n*</STRONG> versions read at most <EM>n</EM> characters, letting
- the application prevent overflow of the input buffer.
+ The <STRONG>getnstr</STRONG>, <STRONG>mvgetnstr</STRONG>, <STRONG>mvwgetnstr</STRONG>, and <STRONG>wgetnstr</STRONG> functions are
+ identical to the <STRONG>getstr</STRONG>, <STRONG>mvgetstr</STRONG>, <STRONG>mvwgetstr</STRONG>, and <STRONG>wgetstr</STRONG> functions,
+ respectively, except that the <STRONG>*n*</STRONG> versions read at most <EM>n</EM> characters,
+ letting the application prevent overflow of the input buffer.
</PRE><H2><a name="h2-NOTES">NOTES</a></H2><PRE>
Any of these functions other than <STRONG>wgetnstr</STRONG> may be macros.
- Using <STRONG>getstr</STRONG>, <STRONG>mvgetstr</STRONG>, <STRONG>mvwgetstr</STRONG>, or <STRONG>wgetstr</STRONG> to read a line that over-
- flows the array pointed to by <STRONG>str</STRONG> causes undefined results. The use of
- <STRONG>getnstr</STRONG>, <STRONG>mvgetnstr</STRONG>, <STRONG>mvwgetnstr</STRONG>, or <STRONG>wgetnstr</STRONG>, respectively, is recom-
- mended.
+ Using <STRONG>getstr</STRONG>, <STRONG>mvgetstr</STRONG>, <STRONG>mvwgetstr</STRONG>, or <STRONG>wgetstr</STRONG> to read a line that
+ overflows the array pointed to by <STRONG>str</STRONG> causes undefined results. The
+ use of <STRONG>getnstr</STRONG>, <STRONG>mvgetnstr</STRONG>, <STRONG>mvwgetnstr</STRONG>, or <STRONG>wgetnstr</STRONG>, respectively, is
+ recommended.
</PRE><H2><a name="h2-RETURN-VALUE">RETURN VALUE</a></H2><PRE>
- All of these functions return the integer <STRONG>OK</STRONG> upon successful comple-
- tion. (SVr4 specifies only "an integer value other than <STRONG>ERR</STRONG>") If un-
- successful, they return <STRONG>ERR</STRONG>.
+ All of these functions return the integer <STRONG>OK</STRONG> upon successful
+ completion. (SVr4 specifies only "an integer value other than <STRONG>ERR</STRONG>") If
+ unsuccessful, they return <STRONG>ERR</STRONG>.
X/Open defines no error conditions.
<STRONG>o</STRONG> if the associated call to <STRONG>wgetch</STRONG> failed.
- 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>.
+ This implementation provides an extension as well. If a <STRONG>SIGWINCH</STRONG>
+ interrupts 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 movement using
+ 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.
These functions are described in The Single Unix Specification, Version
2. No error conditions are defined.
- This implementation returns <STRONG>ERR</STRONG> if the window pointer is null, or if
+ 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).
+ 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",
+ 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.
<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.
+ <STRONG>o</STRONG> Solaris xcurses provides both: its wide-character <STRONG>wget_nstr</STRONG>
+ reserves 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
+ 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.
+ <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
+ <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
+ 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
+ <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.
+ <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
+ terminating NUL.
- Although <STRONG>getnstr</STRONG> is equivalent to a series of calls to <STRONG>getch</STRONG>, it also
- makes changes to the curses modes to allow simple editing of the input
+ Although <STRONG>getnstr</STRONG> is equivalent to a series of calls to <STRONG>getch</STRONG>, it also
+ makes changes to the curses modes to allow simple editing of the input
buffer:
- <STRONG>o</STRONG> <STRONG>getnstr</STRONG> saves the current value of the <STRONG>nl</STRONG>, <STRONG>echo</STRONG>, <STRONG>raw</STRONG> and <STRONG>cbreak</STRONG>
+ <STRONG>o</STRONG> <STRONG>getnstr</STRONG> saves the current value of the <STRONG>nl</STRONG>, <STRONG>echo</STRONG>, <STRONG>raw</STRONG> and <STRONG>cbreak</STRONG>
modes, and sets <STRONG>nl</STRONG>, <STRONG>noecho</STRONG>, <STRONG>noraw</STRONG>, and <STRONG>cbreak</STRONG>.
- <STRONG>getnstr</STRONG> handles the echoing of characters, rather than relying on
+ <STRONG>getnstr</STRONG> handles the echoing of characters, rather than relying on
the caller to set an appropriate mode.
- <STRONG>o</STRONG> It also obtains the <EM>erase</EM> and <EM>kill</EM> characters from <STRONG>erasechar</STRONG> and
+ <STRONG>o</STRONG> It also obtains the <EM>erase</EM> and <EM>kill</EM> characters from <STRONG>erasechar</STRONG> and
<STRONG>killchar</STRONG>, respectively.
<STRONG>o</STRONG> On return, <STRONG>getnstr</STRONG> restores the modes to their previous values.
Other implementations differ in their treatment of special characters:
- <STRONG>o</STRONG> While they may set the <EM>echo</EM> mode, other implementations do not mod-
- ify the <EM>raw</EM> mode, They may take the <EM>cbreak</EM> mode set by the caller
- into account when deciding whether to handle echoing within <STRONG>getnstr</STRONG>
- or as a side-effect of the <STRONG>getch</STRONG> calls.
+ <STRONG>o</STRONG> While they may set the <EM>echo</EM> mode, other implementations do not
+ modify the <EM>raw</EM> mode, They may take the <EM>cbreak</EM> mode set by the
+ caller into account when deciding whether to handle echoing within
+ <STRONG>getnstr</STRONG> or as a side-effect of the <STRONG>getch</STRONG> calls.
<STRONG>o</STRONG> The original ncurses (as <EM>pcurses</EM> in 1986) set <STRONG>noraw</STRONG> and <STRONG>cbreak</STRONG> when
- accepting input for <STRONG>getnstr</STRONG>. That may have been done to make func-
- tion- and cursor-keys work; it is not necessary with ncurses.
+ accepting input for <STRONG>getnstr</STRONG>. That may have been done to make
+ function- and cursor-keys work; it is not necessary with ncurses.
- Since 1995, ncurses has provided signal handlers for INTR and QUIT
- (e.g., <STRONG>^C</STRONG> or <STRONG>^\</STRONG>). With the <STRONG>noraw</STRONG> and <STRONG>cbreak</STRONG> settings, those may
- catch a signal and stop the program, where other implementations
+ Since 1995, ncurses has provided signal handlers for INTR and QUIT
+ (e.g., <STRONG>^C</STRONG> or <STRONG>^\</STRONG>). With the <STRONG>noraw</STRONG> and <STRONG>cbreak</STRONG> settings, those may
+ catch a signal and stop the program, where other implementations
allow one to enter those characters in the buffer.
<STRONG>o</STRONG> Starting in 2021 (ncurses 6.3), <STRONG>getnstr</STRONG> sets <STRONG>raw</STRONG>, rather than <STRONG>noraw</STRONG>
- and <STRONG>cbreak</STRONG> for better compatibility with SVr4-curses, e.g., allow-
- ing one to enter a <STRONG>^C</STRONG> into the buffer.
+ and <STRONG>cbreak</STRONG> for better compatibility with SVr4-curses, e.g.,
+ allowing one to enter a <STRONG>^C</STRONG> into the buffer.
</PRE><H2><a name="h2-SEE-ALSO">SEE ALSO</a></H2><PRE>
-ncurses 6.4 2023-08-05 <STRONG><A HREF="curs_getstr.3x.html">curs_getstr(3x)</A></STRONG>
+ncurses 6.4 2023-09-16 <STRONG><A HREF="curs_getstr.3x.html">curs_getstr(3x)</A></STRONG>
</PRE>
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