X-Git-Url: https://ncurses.scripts.mit.edu/?p=ncurses.git;a=blobdiff_plain;f=man%2Fcurs_clear.3x;h=9d2872a3dd57f4bef15d313431c9f5b6ef59841d;hp=305c608a49ca5255a824680693e660b96778fb24;hb=e5d1530ca229aef94a3c84ad33f8ae89f35c4045;hpb=96d6b16de0d487e5d3aed0302a179dbce11b5d96 diff --git a/man/curs_clear.3x b/man/curs_clear.3x index 305c608a..9d2872a3 100644 --- a/man/curs_clear.3x +++ b/man/curs_clear.3x @@ -1,5 +1,6 @@ .\"*************************************************************************** -.\" Copyright (c) 1998-2007,2010 Free Software Foundation, Inc. * +.\" Copyright 2018,2020 Thomas E. Dickey * +.\" Copyright 1998-2010,2016 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 * @@ -26,10 +27,14 @@ .\" authorization. * .\"*************************************************************************** .\" -.\" $Id: curs_clear.3x,v 1.14 2010/12/04 18:36:44 tom Exp $ +.\" $Id: curs_clear.3x,v 1.19 2020/10/03 21:43:37 tom Exp $ .TH curs_clear 3X "" .na .hy 0 +.de bP +.ie n .IP \(bu 4 +.el .IP \(bu 2 +.. .SH NAME \fBerase\fR, \fBwerase\fR, @@ -42,20 +47,20 @@ .ad .hy .SH SYNOPSIS -\fB# include \fR +\fB#include \fR .sp \fBint erase(void);\fR .br \fBint werase(WINDOW *win);\fR -.br +.sp \fBint clear(void);\fR .br \fBint wclear(WINDOW *win);\fR -.br +.sp \fBint clrtobot(void);\fR .br \fBint wclrtobot(WINDOW *win);\fR -.br +.sp \fBint clrtoeol(void);\fR .br \fBint wclrtoeol(WINDOW *win);\fR @@ -70,7 +75,8 @@ cleared completely on the next call to \fBwrefresh\fR for that window and repainted from scratch. .PP The \fBclrtobot\fR and \fBwclrtobot\fR routines erase from the cursor to the -end of screen. That is, they erase all lines below the cursor in the window. +end of screen. +That is, they erase all lines below the cursor in the window. Also, the current line to the right of the cursor, inclusive, is erased. .PP The \fBclrtoeol\fR and \fBwclrtoeol\fR routines erase the current line @@ -80,28 +86,38 @@ Blanks created by erasure have the current background rendition (as set by \fBwbkgdset\fR) merged into them. .SH RETURN VALUE All routines return the integer \fBOK\fR on success and \fBERR\fP on failure. -The SVr4.0 manual says "or a -non-negative integer if \fBimmedok\fR is set", but this appears to be an error. .PP X/Open defines no error conditions. In this implementation, -functions using a window pointer parameter return an error if it is null. +.bP +functions using a window pointer parameter return an error if it is null +.bP +\fBwclrtoeol\fP returns an error +if the cursor position is about to wrap. .SH NOTES Note that \fBerase\fR, \fBwerase\fR, \fBclear\fR, \fBwclear\fR, \fBclrtobot\fR, and \fBclrtoeol\fR may be macros. .SH PORTABILITY -These functions are described in the XSI Curses standard, Issue 4. The +These functions are described in the XSI Curses standard, Issue 4. +The standard specifies that they return \fBERR\fR on failure, but specifies no error conditions. .PP +The SVr4.0 manual says that these functions could +return "a non-negative integer if \fBimmedok\fR is set", +referring to the return-value of \fBwrefresh\fP. +In that implementation, \fBwrefresh\fP would return a count of +the number of characters written to the terminal. +.PP Some historic curses implementations had, as an undocumented feature, the ability to do the equivalent of \fBclearok(..., 1)\fR by saying -\fBtouchwin(stdscr)\fR or \fBclear(stdscr)\fR. This will not work under +\fBtouchwin(stdscr)\fR or \fBclear(stdscr)\fR. +This will not work under ncurses. .PP This implementation, and others such as Solaris, sets the current position to 0,0 after erasing -via \fBwerase()\fP and \fBwclear()\fP. +via \fBwerase\fP and \fBwclear\fP. That fact is not documented in other implementations, and may not be true of implementations which were not derived from SVr4 source.