/* OpSys Spring 2005
   Sample program that calls stat()

   Usage:  ./showfileattr filename

   calls stat() on the file specified on the command line and
   prints out information about the file.


   For reference, here is the definition of struct stat

struct stat {
  dev_t         st_dev;       device 
  ino_t         st_ino;       inode 
  mode_t        st_mode;      protection 
  nlink_t       st_nlink;     number of hard links 
  uid_t         st_uid;       user ID of owner 
  gid_t         st_gid;       group ID of owner 
  dev_t         st_rdev;      device type (if inode device) 
  off_t         st_size;      total size, in bytes 
  blksize_t     st_blksize;   blocksize for filesystem I/O 
  blkcnt_t      st_blocks;    number of blocks allocated 
  time_t        st_atime;     time of last access 
  time_t        st_mtime;     time of last modification 
  time_t        st_ctime;     time of last change 
};
 
*/

#include <stdio.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <stdlib.h>		/* exit */
#include <errno.h>		/* errno */
#include <string.h>  		/* strerror */
#include <time.h>		/* ctime */

/* showfile calls stat on the filename passed in
   and prints out the value of some of the fields
   in the struct stat filled in.
*/

void showfile( const char *filename ) {
  struct stat sbuf;

  if (stat(filename,&sbuf)==-1) {
	/* stat returned an error! */
	fprintf(stderr,"Error stating file %s: %s\n",filename,
        strerror(errno));
	return;
  }

  printf("Information about %s\n",filename);

  if (S_ISREG(sbuf.st_mode)) {
	/* This is a regular file */
	printf("\tType: Regular File\n");
  } else if (S_ISDIR(sbuf.st_mode)) {
	/* This is a directory */
	printf("\tType: Directory\n");
  } else {
	/* could be a number of other things... */
	printf("\tType: something other than regular file or directory...\n");
  }
  printf("\tOwner: %d\n",(int) sbuf.st_uid);
  printf("\tSize: %d\n",(int) sbuf.st_size);
  /* check some permission bits */
  if (sbuf.st_mode & S_IROTH) {
    printf("\tAnyone can read\n");
  }
  if (sbuf.st_mode & S_IWOTH) {
    printf("\tAnyone can write\n");
  }

  if (sbuf.st_mode & S_IXOTH) {
    printf("\tAnyone can execute\n");
  }


/* actual usage is # 512 byte blocks */
  printf("\tDisk space used: %d\n",512 * (int)sbuf.st_blocks);
  printf("\tLast access: %s",ctime(&sbuf.st_atime));
  printf("\tLast modification: %s",ctime(&sbuf.st_mtime));
  printf("\tLast status change: %s",ctime(&sbuf.st_ctime));
}


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

  if (argc<2) {
	printf("You have to tell me what file!\n");
	exit(1);
  }
  showfile(argv[1]);
  return(0);
}