FOSS Exp:10

[student@localhost ~]$ vi 10exp.c

/*This program takes one or more file/directory names as command  
line input and reports the following information on the file:          
(a) File type (b) Number of links (c) Time of last access          
(d) Read, write, and execute permissions                              
Syntax: ./10filestat <file|dir> [<file|dir>]                          
Arguments: Expects atleast one file name or directory name as argument,  
and accepts more than 1 argument also as file names or directory names                                                        
Returns: File statistics which include the type of file, number of links  
to the file, time the file was last accessed, and read, write, and execute
permissions of the file (or directory) */
#include<unistd.h> /* F_OK, STDIN_FILENO, STDERR_FILENO, etc. */
#include<sys/stat.h> /* struct stat */
#include<sys/types.h> /* S_IFMT */
#include<stdio.h> /* fprintf, printf, sprintf, etc. */
#include<stdlib.h> /* exit, etc. */
#include<time.h> /* ctime */
/* Define all the error messages */
char *error_msg[]={"\nUsage: ./10filestat <file|dir> [<file|dir>]\n\n","\nFile does not exist !!\n\n","\nError doing 'stat' on file\n\n"};
/* Declare the prototype for function 'print_error' */
void print_error(int msg_num,int exit_code,int exit_flag);
int main(int argc,char *argv[])
{
  int i;/* A counter */
  mode_t file_perm; /* File permissions */
  struct stat file_details;/* Detailed file info */
  char success_msg[]="\nCommand executed successfully\n\n";
/* Check if correct number of arguments are supplied */
   if(argc<2)
      print_error(0,2,1);
  /* Loop through all the filenames */
   for(i=1;i<argc;i++)
    {
       /* Display the filename */
       printf("\n%s\n%s\n%s\n","----------------",argv[i],"----------------");
   
        /* Check if the file exists */
       if(access(argv[i],F_OK)==-1)
         {
            print_error(1,3,0);
            continue;
          }
     
      /*Retrieve the file details*/
       if(lstat(argv[i],&file_details)<0)
         {
           print_error(2,4,0);
           continue;
         }

     /* Get the file type */
      if(S_ISREG(file_details.st_mode))
printf("File type : Regular\n");
      else if(S_ISDIR(file_details.st_mode))
    printf("File type : Directory\n");
 else if(S_ISLNK(file_details.st_mode))
      printf("File type : Symbolic link\n");
     else
       printf("File type:Other");
/* Get the number of links */
printf("Number of links : %d\n",(int)file_details.st_nlink);
/* Get the time of last access of the file */
printf("Time of last access : %s",ctime(&file_details.st_atime));
/* Get the file permissions */
printf("File Permissions:\n");
file_perm=file_details.st_mode&~S_IFMT;
printf("\tUser : ");
if(file_perm&S_IRUSR)
  printf("Readable, ");
else
    printf("Not readable,");
if(file_perm&S_IWUSR)
  printf("Writable, ");
else
  printf("Not writable, ");
if(file_perm&S_IXUSR)
  printf("Executable\n");
else
   printf("Not executable\n");

       printf("\tGroup : ");
if(file_perm&S_IRGRP)
  printf("Readable, ");
else
  printf("Not readable, ");
if(file_perm&S_IWGRP)
 printf("Writable, ");
else
 printf("Not writable, ");
if(file_perm&S_IXGRP)
 printf("Executable\n");
else
 printf("Not executable\n");

printf("\tOthers : ");
if(file_perm&S_IROTH)
  printf("Readable, ");
else
  printf("Not readable, ");
if(file_perm&S_IWOTH)
  printf("Writable, ");
else
  printf("Not writable, ");
if(file_perm&S_IXOTH)
  printf("Executable\n");
else
          printf("Not executable\n");
       }
printf("%s",success_msg);
   return(1);
}
void print_error(int error_index,int exit_code,int exit_flag)
{
   fprintf(stderr,"%s\n",error_msg[error_index]);
     if(exit_flag)
        exit(exit_code);
}

[student@localhost ~]$ cc 10exp.c
[student@localhost ~]$ ./a.out
Usage: ./10filestat <file|dir> [<file|dir>]

[student@localhost ~]$ cc -o 10filestat 10exp.c
[student@localhost ~]$ ./10filestat Documents

----------------
Documents
----------------
File type : Directory
Number of links : 3
Time of last access : Thu Jan  5 17:33:52 2017
File Permissions:
        User : Readable, Writable, Executable
        Group : Readable, Not writable, Executable
        Others : Readable, Not writable, Executable

Command executed successfully

[student@localhost ~]$ ./10filestat cse1

----------------
cse1
----------------
File type : Regular
Number of links : 1
Time of last access : Thu Jan  5 18:21:43 2017
File Permissions:
        User : Readable, Writable, Not executable
        Group : Readable, Not writable, Not executable
        Others : Readable, Not writable, Not executable

Command executed successfully
[student@localhost ~]$ chmod u=rwx,g=rx,o=r cse1
[student@localhost ~]$ ./10filestat cse1

----------------
cse1
----------------
File type : Regular
Number of links : 1
Time of last access : Thu Jan  5 18:33:41 2017
File Permissions:
  User : Readable, Writable, Executable
        Group : Readable, Not writable, Executable
        Others : Readable, Not writable, Not executable

Command executed successfully