C language to change the contents of the relevant operational functions detailed _c language

C language Fchdir () function: Change the current working directory
header file:

 #include <unistd.h>

To define a function:

int fchdir (int fd);

Function Description: Fchdir () is used to change the current working directory to a parameter FD refers to the file descriptor.

Return value: Returns 0 for successful execution, failure returns-1, errno as error code.

Example

#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include < unistd.h>
Main ()
{
  int fd;
  FD = open ("/tmp", o_rdonly);
  Fchdir (FD);
  printf ("Current working directory:%s \ n", GETCWD (null, NULL));
  Close (FD);
}

Perform:

Current working directory:/tmp

C language Rewinddir () function: Resets the location of the read directory to the beginning position
header file:

#include <sys/types.h>  #include <dirent.h>

To define a function:

void Rewinddir (DIR *dir);

Function Description: Rewinddir () is used to set the parameter dir directory stream the current read location is the original start of the read location.

Error code: EBADF dir is an invalid directory stream.

Example

#include <sys/types.h>
#include <dirent.h>
#include <unistd.h>
main ()
{
  dir * dir;
  struct dirent *ptr;
  dir = Opendir ("/etc/rc.d");
  while (ptr = Readdir (dir))!= NULL)
  {
    printf ("D_name:%s\n", ptr->d_name);
  }
  Rewinddir (dir);
  printf ("Readdir again!\n");
  while (ptr = Readdir (dir))!= NULL)
  {
    printf ("D_name:%s\n", ptr->d_name);
  }
  Closedir (dir);

Perform:

D_name:.
D_name:..
D_NAME:INIT.D
d_name:rc0.d
d_name:rc1.d
d_name:rc2.d
d_name:rc3.d
d_name:rc4.d : rc5.d
d_name:rc6.d
d_name:rc
d_name:rc.local
d_name:rc.sysinit
readdir D_name:.
D_name:..
D_NAME:INIT.D
d_name:rc0.d
d_name:rc1.d
d_name:rc2.d
d_name:rc3.d
d_name:rc4.d
D _NAME:RC5.D
d_name:rc6.d
d_name:rc
d_name:rc.local
d_name:rc.sysinit