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regsub.c
/*
* 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.
*/
#include <stdio.h>
#include <string.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
hs_regsub(prog, source, dest)
const hs_regexp *prog;
const char *source;
char *dest;
{
register char *src;
register char *dst;
register char c;
register int no;
register int len;
if (prog == NULL || source == NULL || dest == NULL) {
hs_regerror("NULL parm to regsub");
return;
}
if (UCHARAT(prog->program) != MAGIC) {
hs_regerror("damaged regexp fed to regsub");
return;
}
src = (char *)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. */
hs_regerror("damaged match string");
return;
}
}
}
*dst++ = '\0';
}
hs_regexp
Definition regexp.h:50