gno/bin/vi/regsub.c
gdr-ftp 784e3de7cd Initial checkin of aroff, binprint, center, less, ls, make, makemake,
passwd, ps, purge, shutdown, stty, upper, and vi.  These sources are
for the versions of the utils shipped with GNO v2.0.4.
1998-03-09 08:30:21 +00:00

112 lines
3.3 KiB
C

/*
* NOTICE NOTICE NOTICE NOTICE NOTICE NOTICE NOTICE NOTICE NOTICE NOTICE
*
* This is NOT the original regular expression code as written by
* Henry Spencer. This code has been modified specifically for use
* with the STEVIE editor, and should not be used apart from compiling
* STEVIE. If you want a good regular expression library, get the
* original code. The copyright notice that follows is from the
* original.
*
* NOTICE NOTICE NOTICE NOTICE NOTICE NOTICE NOTICE NOTICE NOTICE NOTICE
*
* regsub
*
* Copyright (c) 1986 by University of Toronto.
* Written by Henry Spencer. Not derived from licensed software.
*
* Permission is granted to anyone to use this software for any
* purpose on any computer system, and to redistribute it freely,
* subject to the following restrictions:
*
* 1. The author is not responsible for the consequences of use of
* this software, no matter how awful, even if they arise
* from defects in it.
*
* 2. The origin of this software must not be misrepresented, either
* by explicit claim or by omission.
*
* 3. Altered versions must be plainly marked as such, and must not
* be misrepresented as being the original software.
*
* $Log: regsub.c,v $
* Revision 1.1 1998/03/09 08:29:50 gdr-ftp
* Initial checkin of aroff, binprint, center, less, ls, make, makemake,
* passwd, ps, purge, shutdown, stty, upper, and vi. These sources are
* for the versions of the utils shipped with GNO v2.0.4.
*
* Revision 1.2 88/04/28 08:11:25 tony
* First modification of the regexp library. Added an external variable
* 'reg_ic' which can be set to indicate that case should be ignored.
* Added a new parameter to regexec() to indicate that the given string
* comes from the beginning of a line and is thus eligible to match
* 'beginning-of-line'.
*
*/
#include "env.h"
#ifdef MEGAMAX
overlay "regexp"
#endif
#include <stdio.h>
#include "regexp.h"
#include "regmagic.h"
#ifndef CHARBITS
#define UCHARAT(p) ((int)*(unsigned char *)(p))
#else
#define UCHARAT(p) ((int)*(p)&CHARBITS)
#endif
/*
- regsub - perform substitutions after a regexp match
*/
void
regsub(prog, source, dest)
regexp *prog;
char *source;
char *dest;
{
register char *src;
register char *dst;
register char c;
register int no;
register int len;
extern char *strncpy();
if (prog == NULL || source == NULL || dest == NULL) {
regerror("NULL parm to regsub");
return;
}
if (UCHARAT(prog->program) != MAGIC) {
regerror("damaged regexp fed to regsub");
return;
}
src = source;
dst = dest;
while ((c = *src++) != '\0') {
if (c == '&')
no = 0;
else if (c == '\\' && '0' <= *src && *src <= '9')
no = *src++ - '0';
else
no = -1;
if (no < 0) { /* Ordinary character. */
if (c == '\\' && (*src == '\\' || *src == '&'))
c = *src++;
*dst++ = c;
} else if (prog->startp[no] != NULL && prog->endp[no] != NULL) {
len = prog->endp[no] - prog->startp[no];
(void) strncpy(dst, prog->startp[no], len);
dst += len;
if (len != 0 && *(dst - 1) == '\0') { /* strncpy hit NUL. */
regerror("damaged match string");
return;
}
}
}
*dst = '\0';
}