pali.c

#include <stdio.h>
#include <string.h>

int main(int argc, char **argv) {
    if (argc < 2)
        fprintf(stderr, "Please provide a string\n");
    const char *w = argv[1];
    int i = 0;
    int j = strlen(w)-1;
    while (i < j) {
        if (w[i] != w[j]) {
            printf("Not a palindrome\n");
            return 1;
        }
        i++;
        j--;
    }
    printf("A palindrome\n");

    return 0;
}