[C언어] 문자열 치환함수

출처 : http://mwultong.blogspot.com/2006/10/c-string-replace-all.html

char *replaceAll(char *s, const char *olds, const char *news) 

{

char *result, *sr;

size_t i, count = 0;

size_t oldlen = strlen(olds); if (oldlen < 1) return s;

size_t newlen = strlen(news);

if (newlen != oldlen) {

for (i = 0; s[i] != '\0';) {

if (memcmp(&s[i], olds, oldlen) == 0) count++, i += oldlen;

else i++;

}

} else i = strlen(s);

result = (char *) malloc(i + 1 + count * (newlen - oldlen));

if (result == NULL) return NULL;

sr = result;

while (*s) {

if (memcmp(s, olds, oldlen) == 0) {

memcpy(sr, news, newlen);

sr += newlen;

s  += oldlen;

} else *sr++ = *s++;

}

*sr = '\0';

return result;

}