ncurses 6.0 - patch 20160723

[ncurses.git] / man / resizeterm.3x

diff --git a/man/resizeterm.3x b/man/resizeterm.3x
index 177e7057ba8e87dd45e744d14fbece80f4a13b5e..b88f68f351ff23a059271aaba3e97248e894cadd 100644 (file)
--- a/man/resizeterm.3x
+++ b/man/resizeterm.3x
@@ -28,8 +28,11 @@
 .\"
 .\" Author: Thomas E. Dickey 1996-on
 .\"
 .\"
 .\" Author: Thomas E. Dickey 1996-on
 .\"

-.\" $Id: resizeterm.3x,v 1.19 2015/06/06 23:38:18 tom Exp $
+.\" $Id: resizeterm.3x,v 1.21 2015/09/26 19:55:32 tom Exp $

 .TH resizeterm 3X ""
 .TH resizeterm 3X ""

+.de bP
+.IP \(bu 4
+..

 .SH NAME
 \fBis_term_resized\fR,
 \fBresize_term\fR,
 .SH NAME
 \fBis_term_resized\fR,
 \fBresize_term\fR,


@@ -81,17 +84,43 @@ context where \fBmalloc\fR or \fBrealloc\fR may have been interrupted,
 since it uses those functions.
 .PP
 If ncurses is configured to supply its own SIGWINCH handler,
 since it uses those functions.
 .PP
 If ncurses is configured to supply its own SIGWINCH handler,

-the \fBresizeterm\fR function \fBungetch\fP's a \fBKEY_RESIZE\fR which
-will be read on the next call to \fBgetch\fR.
-This is used to alert an application that the screen size has changed,
+.bP
+on receipt of a SIGWINCH, the handler sets a flag
+.bP
+which is tested in \fBwgetch\fP and \fBdoupdate\fP,
+.bP
+in turn, calling the \fBresizeterm\fR function,
+.bP
+which \fBungetch\fP's a \fBKEY_RESIZE\fR which
+will be read on the next call to \fBwgetch\fR.
+.IP
+The \fBKEY_RESIZE\fP alerts an application that the screen size has changed,

 and that it should repaint special features such as pads that cannot
 be done automatically.
 and that it should repaint special features such as pads that cannot
 be done automatically.

+.IP
+Calling \fBresizeterm\fP or \fBresize_term\fP
+directly from a signal handler is unsafe.
+This indirect method is used to provide a safe way to resize the ncurses
+data structures.

 .PP
 If the environment variables \fBLINES\fP or \fBCOLUMNS\fP are set,
 this overrides the library's use of the window size obtained from
 the operating system.
 Thus, even if a SIGWINCH is received,
 no screen size change may be recorded.
 .PP
 If the environment variables \fBLINES\fP or \fBCOLUMNS\fP are set,
 this overrides the library's use of the window size obtained from
 the operating system.
 Thus, even if a SIGWINCH is received,
 no screen size change may be recorded.

+.SH PORTABILITY
+.PP
+It is possible to resize the screen with SVr4 curses,
+by
+.bP
+exiting curses with \fBendwin\fP(3X) and
+.bP
+resuming using \fBrefresh\fP(3X).
+.PP
+Doing that clears the screen and is visually distracting.
+.PP
+This extension of ncurses was introduced in mid-1995.
+It was adopted in NetBSD curses (2001) and PDCurses (2003).

 .SH SEE ALSO
 \fBcurs_getch\fR(3X),
 \fBcurs_variables\fR(3X),
 .SH SEE ALSO
 \fBcurs_getch\fR(3X),
 \fBcurs_variables\fR(3X),