Read in a file and handle errors and write to a file and handle errors

read_file.c

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

#define bufSize 1024

int main(int argc, char const *argv[])
{
    FILE *in;
    char buf[bufSize];
    if (!(in = fopen("test.txt", "r"))) {
        fprintf(stderr, "Can't open the file.\n");
        return 1;
    }
    
    while (fgets(buf, sizeof(buf), in) != NULL)
    {
        buf[strlen(buf) - 1] = '\0'; // eat the newline fgets() stores
        printf("%s\n", buf);
    }
    
    fclose(in);
    return 0;
}

write_file.c

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

int main(int argc, char const *argv[])
{
  	const char* text = "Write this to the file";
    FILE *out;
    if (!(out = fopen("output.txt", "w"))) {
        fprintf(stderr, "Can't write to the file.\n");
        return 1;
    }
    fprintf(out, text);
    fclose(out);
    return 0;
}