CS456 - Systems Programming Spring 2026

Displaying ./code/h2ex/getinfo.c

/*

takes a file via command line, prints size and permissions

*/

#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <fcntl.h>
#include <errno.h>

//this is the header file I wrote,
//note that header files i create use quotes as opposed to angle brackets
#include "extras.h"

int main(int argc, char **argv){

	// prints usage statement if not enough arguments found
	if(argc < 2){
		fprintf(stderr, "Usage %s file\n", argv[0]);
		exit(1);
	}

	//opening file, getting file descriptor
	int fd = open(argv[1], O_RDONLY);

	// checking return value for open
	if(fd == -1){
		perror("open");
		exit(-1);
	}

	//using the get_fdSize function to get file size
	int size = get_fdSize(fd);

	//using get_fdPerms to get file permissions
	int perms = get_fdPerms(fd);

	//print out values
	printf("size= %d bytes, perms %o\n", size, perms);

	close(fd);

	return 0;



}