jehanne/sys/src/lib/regexp/rregsub.c

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/*
* This file is part of the UCB release of Plan 9. It is subject to the license
* terms in the LICENSE file found in the top-level directory of this
* distribution and at http://akaros.cs.berkeley.edu/files/Plan9License. No
* part of the UCB release of Plan 9, including this file, may be copied,
* modified, propagated, or distributed except according to the terms contained
* in the LICENSE file.
*/
#include <u.h>
#include <lib9.h>
#include "regexp.h"
/* substitute into one string using the matches from the last regexec() */
extern void
rregsub(Rune *sp, /* source string */
Rune *dp, /* destination string */
int dlen,
Resub *mp, /* subexpression elements */
int ms) /* number of elements pointed to by mp */
{
Rune *ssp, *ep;
int i;
ep = dp+(dlen/sizeof(Rune))-1;
while(*sp != '\0'){
if(*sp == '\\'){
switch(*++sp){
case '0':
case '1':
case '2':
case '3':
case '4':
case '5':
case '6':
case '7':
case '8':
case '9':
i = *sp-'0';
if(mp[i].rsp != 0 && mp!=0 && ms>i)
for(ssp = mp[i].rsp;
ssp < mp[i].rep;
ssp++)
if(dp < ep)
*dp++ = *ssp;
break;
case '\\':
if(dp < ep)
*dp++ = '\\';
break;
case '\0':
sp--;
break;
default:
if(dp < ep)
*dp++ = *sp;
break;
}
}else if(*sp == '&'){
if(mp[0].rsp != 0 && mp!=0 && ms>0)
if(mp[0].rsp != 0)
for(ssp = mp[0].rsp;
ssp < mp[0].rep; ssp++)
if(dp < ep)
*dp++ = *ssp;
}else{
if(dp < ep)
*dp++ = *sp;
}
sp++;
}
*dp = '\0';
}