X-Git-Url: http://ncurses.scripts.mit.edu/?p=ncurses.git;a=blobdiff_plain;f=man%2Fresizeterm.3x;h=b88f68f351ff23a059271aaba3e97248e894cadd;hp=177e7057ba8e87dd45e744d14fbece80f4a13b5e;hb=a919b0ee00a6287c7e29330be52f9bb557503288;hpb=db5f7f4f146a91ba8ec7f1df8e9d7f9d2d7c74fd

diff --git a/man/resizeterm.3x b/man/resizeterm.3x
index 177e7057..b88f68f3 100644
--- a/man/resizeterm.3x
+++ b/man/resizeterm.3x
@@ -28,8 +28,11 @@
 .\"
 .\" 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 ""
+.de bP
+.IP \(bu 4
+..
 .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,
-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.
+.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.
+.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),