busybox/libbb/replace.c

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/* vi: set sw=4 ts=4: */
/*
* Utility routines.
*
* Copyright (C) 1999-2004 by Erik Andersen <andersen@codepoet.org>
*
* Licensed under GPLv2 or later, see file LICENSE in this source tree.
*/
//kbuild:lib-y += replace.o
#include "libbb.h"
unsigned FAST_FUNC count_strstr(const char *str, const char *sub)
{
size_t sub_len = strlen(sub);
unsigned count = 0;
/* If sub is empty, avoid an infinite loop */
if (sub_len == 0)
return strlen(str) + 1;
while ((str = strstr(str, sub)) != NULL) {
count++;
str += sub_len;
}
return count;
}
char* FAST_FUNC xmalloc_substitute_string(const char *src, int count, const char *sub, const char *repl)
{
char *buf, *dst, *end;
size_t sub_len = strlen(sub);
size_t repl_len = strlen(repl);
//dbg_msg("subst(s:'%s',count:%d,sub:'%s',repl:'%s'", src, count, sub, repl);
buf = dst = xmalloc(strlen(src) + count * ((int)repl_len - (int)sub_len) + 1);
/* we replace each sub with repl */
while ((end = strstr(src, sub)) != NULL) {
dst = mempcpy(dst, src, end - src);
dst = mempcpy(dst, repl, repl_len);
/*src = end + 1; - GNU findutils 4.5.10 doesn't do this... */
src = end + sub_len; /* but this. Try "xargs -Iaa echo aaa" */
}
strcpy(dst, src);
//dbg_msg("subst9:'%s'", buf);
return buf;
}