How to pass a string that ends with: !x as a command line argument?

Question

linux

Basically, I wrote this code:

Program source

#include <stdio.h>
#include <stdlib.h>

size_t str_copy2buf(size_t n, char buf[n], const char str[])
{
    size_t i;

    for (i = 0; i < n; i++) {
        if ((buf[i] = str[i]) == '\0')
            break;
    }
    return i;
}

size_t str_append2buf(size_t n, char buf[n], const char str[])
{
    size_t i, j;

    for (i = 0; i < n; i++) {
        if (buf[i] == '\0')
            break;
    }
    for (j = 0; i < n; i++) {
        if ((buf[i] = str[j]) == '\0')
            break;
        j++;
    }
    return i;
}

int main(int argc, char *argv[argc+1])
{
    char buf[15];
    size_t index;

    index = str_copy2buf(sizeof(buf), buf, argv[1]);
    if (index == sizeof(buf)) {
        fprintf(stderr, "error: copy failed!\n");
        return EXIT_FAILURE;
    }

    index = str_append2buf(sizeof(buf), buf, argv[2]);
    if (index == sizeof(buf)) {
        fprintf(stderr, "error: append failed!\n");
        return EXIT_FAILURE;
    }

    printf("%s\n", buf);
    return EXIT_SUCCESS;
}

Then I do this:

Terminal screenshot

How to make it work?

Answer 1

Try passing in single quotes, not double quotes.
Why are you not satisfied with the standard functions for working with strings?