如何用 int 替换 substring

Question

So i've seen alot of functions like str_replace(str, substr, newstring) but all of them won't work with numbers so i was wondering if anyone had one that would work with both chars and ints or just int ive been looking everywhere and cant figure out a idea on how to write my own. my goal exactly is to be able to replace a string with a int value in the string not just string with string

below is the function i use to replace strings and it worked just fine

void strrpc(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);
}

Answer 1

You can turn an integer into a string by "printing" it to a string:

int id = get_id();
char idstr[20];

sprintf(idstr, "%d", id);

Now you can

char msg[1024] = "Processing item {id} ...";

strrpc(msg, "{id}", idstr);
puts(msg);

But note that the implementation of strrpc you found will work only if the string after replacement is shorter than 1023 character. Also note the the example above could more easily be written as just:

printf("Processing item %d ...\n", get_id());

without the danger of buffer overflow. I don't know what exactly you want to achieve, but perhaps string replacement is not the best solution here. (Just sayin'.)