directory(3B)

NAME
     opendir, readdir, telldir, seekdir, rewinddir, closedir, dirfd -
     directory operations (4.3BSD)

SYNOPSIS
     #include <sys/types.h>
     #include <sys/dir.h>

     DIR *opendir(char *filename);

     struct direct *readdir(DIR *dirp);

     long telldir(DIR *dirp);

     void seekdir(DIR *dirp, long loc);

     void rewinddir(DIR *dirp);

     void closedir(DIR *dirp);

     int dirfd(DIR *dirp)

DESCRIPTION
     The inclusion of <sys/dir.h> selects the 4.3BSD versions of these
     routines.  For the System V versions, include <dirent.h>.

     opendir opens the directory named by filename and associates a directory
     stream with it.  opendir returns a pointer to be used to identify the
     directory stream in subsequent operations.  The pointer NULL is returned
     if filename cannot be accessed, or if it cannot malloc(3) enough memory
     to hold the whole thing.

     readdir returns a pointer to the next directory entry.  It returns NULL
     upon reaching the end of the directory or detecting an invalid seekdir
     operation.

     telldir returns the current location associated with the named directory
     stream.

     seekdir sets the position of the next readdir operation on the directory
     stream. The new position reverts to the one associated with the directory
     stream when the telldir operation was performed.  Values returned by
     telldir are good only for the lifetime of the DIR pointer from which they
     are derived.  If the directory is closed and then reopened, the telldir
     value may be invalidated due to undetected directory compaction.  It is
     safe to use a previous telldir value immediately after a call to opendir
     and before any calls to readdir.

     rewinddir resets the position of the named directory stream to the
     beginning of the directory.
     closedir closes the named directory stream and frees the structure
     associated with the DIR pointer.

     dirfd returns the integer file descriptor associated with the named
     directory stream, see open(2).

     Sample code that searches a directory for entry ``name'':

          len = strlen(name);
          dirp = opendir(".");
          if (dirp == NULL) {
              return NOT_FOUND;
          }
          while ((dp = readdir(dirp)) != NULL) {
              if (dp->d_namlen == len && !strcmp(dp->d_name, name)) {
               closedir(dirp);
               return FOUND;
              }
          }
          closedir(dirp);
          return NOT_FOUND;


SEE ALSO
     open(2), close(2), read(2), lseek(2), directory(3C)