C Search and Replace

A sample C code to search and replace string in a text

void str_replace(char *target, const char *needle, const char *replacement)

{

    char buffer[1024] = { 0 };

    char *insert_point = &buffer[0];

    const char *tmp = target;

    size_t needle_len = strlen(needle);

    size_t repl_len = strlen(replacement);

    

    while (1) {

        const char *p = strstr(tmp, needle);

        

        // walked past last occurrence of needle; copy remaining part

        if (p == NULL) {

            strcpy(insert_point, tmp);

            break;

        }

        

        // copy part before needle

        memcpy(insert_point, tmp, p - tmp);

        insert_point += p - tmp;

        

        // copy replacement string

        memcpy(insert_point, replacement, repl_len);

        insert_point += repl_len;

        

        // adjust pointers, move on

        tmp = p + needle_len;

    }

    

    // write altered string back to target

    strcpy(target, buffer);

}