write a c program to know given file is regular file, character special or it is directory? | CTechnotips

#include "time.h"

#include "sys\stat.h"

#include "stdio.h"

void main(){

    struct stat status;

    FILE *fp;

    stat("c:\\tc\\bin",&status);

    clrscr();

    if (status.st_mode & S_IFDIR)

         printf("It is directory.\n");

    if (status.st_mode & S_IFCHR)

         printf("It is chracter file.");

    if (status.st_mode & S_IFREG)

         printf("It is reggular file.");

    getch();

}

Output: It is directory.

Explanation:

Function int stat (char *, struct stat *) store the information of open file in form of structure struct stat Structure struct stat has been defined in sys\stat.h as

struct stat {

    short  st_dev,   st_ino;

    short  st_mode,  st_nlink;

    int    st_uid,   st_gid;

    short  st_rdev;

    long   st_size,  st_atime;

    long   st_mtime, st_ctime;

};

Here

(m)st_dev: It describe file has stored in which drive of your computer.

(n)st_mode:  It describes various modes of file like file is read only, write only, folder, character file etc.

(o)st_size: It tells the size of file in byte.

(p)St_ctime:It tells last data of modification of

   the file.

There are some macro has been defined in sys\stat.h

 Name         Meaning

 S_IFMT        File type mask

 S_IFDIR       Directory

 S_IFIFO      FIFO special

 S_IFCHR      Character special

 S_IFBLK      Block special

 S_IFREG      Regular file

 S_IREAD      Owner can read

 S_IWRITE     Owner can write

 S_IEXEC      Owner can execute

So masking or bitwise and operation between status.st_mode and S_IFDIR return true if it is directory and so on