ref: 6e3aac3abfd17457d033d433abf820e9bbc8847f
dir: /src/regex/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.
*/
/* This is an altered version. It has been modified by David
Huggins-Daines <dhd@cepstral.com> on 2001-10-23 to use a different
API and be re-entrant and safe and all that good stuff. */
#include "cst_regex.h"
#include "cst_string.h"
#include "cst_error.h"
size_t cst_regsub(const cst_regstate *state, const char *in, char *out, size_t max)
{
const char *src;
char *dst;
int c, no, len;
size_t count;
if (state == NULL || in == NULL) {
cst_errmsg("NULL parm to regsub\n");
cst_error();
}
src = in;
dst = out;
count = 0;
while ((c = *src++) != '\0') {
if (out && dst + 1 > out + max - 1)
break;
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++;
if (out)
*dst++ = c;
count++;
} else if (state->startp[no] != NULL && state->endp[no] != NULL) {
len = state->endp[no] - state->startp[no];
if (out) {
if (dst + len > out + max - 1)
len = (out + max - 1) - dst;
strncpy(dst, state->startp[no], len);
dst += len;
/* strncpy hit NUL. */
if (len != 0 && *(dst-1) == '\0') {
cst_errmsg("damaged match string");
cst_error();
}
}
count += len;
}
}
if (out && dst - out + 1 < (int)max)
*dst++ = '\0';
return count;
}