pathrepl.c revision da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968
/***********************************************************************
* *
* This software is part of the ast package *
* Copyright (c) 1985-2007 AT&T Knowledge Ventures *
* and is licensed under the *
* Common Public License, Version 1.0 *
* by AT&T Knowledge Ventures *
* *
* A copy of the License is available at *
* http://www.opensource.org/licenses/cpl1.0.txt *
* (with md5 checksum 059e8cd6165cb4c31e351f2b69388fd9) *
* *
* Information and Software Systems Research *
* AT&T Research *
* Florham Park NJ *
* *
* Glenn Fowler <gsf@research.att.com> *
* David Korn <dgk@research.att.com> *
* Phong Vo <kpv@research.att.com> *
* *
***********************************************************************/
#pragma prototyped
/*
* Glenn Fowler
* AT&T Bell Laboratories
*
* in place replace of first occurrence of /match/ with /replace/ in path
* end of path returned
*/
#include <ast.h>
char*
pathrepl(register char* path, const char* match, register const char* replace)
{
register const char* m = match;
register const char* r;
char* t;
if (!match) match = "";
if (!replace) replace = "";
if (streq(match, replace))
return(path + strlen(path));
for (;;)
{
while (*path && *path++ != '/');
if (!*path) break;
if (*path == *m)
{
t = path;
while (*m && *m++ == *path) path++;
if (!*m && *path == '/')
{
register char* p;
p = t;
r = replace;
while (p < path && *r) *p++ = *r++;
if (p < path) while (*p++ = *path++);
else if (*r && p >= path)
{
register char* u;
t = path + strlen(path);
u = t + strlen(r);
while (t >= path) *u-- = *t--;
while (*r) *p++ = *r++;
}
else p += strlen(p) + 1;
return(p - 1);
}
path = t;
m = match;
}
}
return(path);
}