petidomo/libtext/wordwrap.c
2000-12-13 15:45:25 +00:00

124 lines
3.4 KiB
C

/*
* $Source$
* $Revision$
* $Date$
*
* Copyright (c) 1996-99 by Peter Simons <simons@cys.de>
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
*
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* 3. All advertising materials mentioning features or use of this software
* must display the following acknowledgement:
* This product includes software developed by Peter Simons.
*
* 4. The name of the author may not be used to endorse or promote products
* derived from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
* IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
#include <ctype.h>
#include "text.h"
/* Wrap a text buffer at a certain column.
This routine wraps all lines in a text buffer that are longer than
the specified limit. Paragraphs will remain untouched. Paragraphs
are separated by an empty line -- a line containing only a line
feed (\\n) that is.
AUTHOR: Peter Simons <simons@rhein.de>
*/
void
text_wordwrap(char * buffer /* Pointer to text buffer. */,
unsigned int line_len /* Maximum line length. */)
{
char * p;
char * q;
char * lastbreak;
unsigned int linepos;
/* First remove all single occurances of a '\n' and crunch
multiple blanks to one. */
for (p = q = buffer; *p != '\0'; ) {
if (*p == '\n') {
if (p[1] == '\n') {
*q++ = *p++;
*q++ = *p++;
}
else {
*q++ = ' ';
p++;
}
} else if (isspace((int)*p)) {
if (isspace((int)q[-1]))
p++;
else
*q++ = *p++;
}
else
*q++ = *p++;
}
/* Wrap the text. */
for (p = buffer, lastbreak = NULL, linepos = 1; *p != '\0'; p++, linepos++) {
if (*p == '\n') {
linepos = 0;
lastbreak = NULL;
}
else if (isspace((int)*p)) {
if (linepos <= line_len) {
lastbreak = p;
}
else {
/* Wrap it. */
if (lastbreak) {
*lastbreak = '\n';
p = lastbreak;
linepos = 0;
lastbreak = NULL;
}
else {
/* Word is too long. <shrug> */
*p = '\n';
linepos = 0;
lastbreak = NULL;
}
}
}
}
if (linepos >= line_len) {
/* Wrap it one last time. */
if (lastbreak) {
*lastbreak = '\n';
p = lastbreak;
linepos = 0;
lastbreak = NULL;
}
}
}