How to read from a file when passing path as an argument using realpath()

Question

I want to pass an argument of a specific file location using realpath() (example: /var/log/message) and by using fprintf print the content of this file on the terminal. This is the code I have so far:

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

int main(int argc, char **argv)
{
    if (argc < 2) {
        printf("Usage: %s <path>\n", argv[0]);
        return 1;
    }
    char *fullpath = realpath(argv[1], NULL);
    FILE *fptr;
    fptr = fopen(fullpath, "r");
    fprintf(fptr, "%s");
    return 0;
}

It doesn't throw errors, but it also doesn't do what I want it to do. When I run it e.g. ./test /var/log/message it will show me this on the terminal:

Segmentation fault (core dumped)

OS version

NAME="Fedora Linux"
VERSION="36

Compiler

gcc

Answer 1

Got back to my function and added some more functionality and now it's working by adding argument for it. What I had to do is to declare that fptr is FILE and c is character type, running a while loop over the file and print its content and with using fgetc stream that content to the terminal.

Current code:

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

int main(int argc, char **argv)
{
    FILE *fptr;
    char c;
    if (argc < 2) {
        printf("You need to grant an arg to %s <path>\n", argv[0]);
        return 1;
    }
    char *fullpath = realpath(argv[1], NULL);
    fptr = fopen(fullpath, "r");
    if (fptr == NULL)
    {
        printf("Cannot open file \n");
        free(fptr);
        exit(0);
    }
    c = fgetc(fptr);
    while (c != EOF)
    {
        printf ("%c", c);
        c = fgetc(fptr);
    }
    fclose(fptr);
    return 0;
}

Thanks all for your assistance.