DIRECTORY(3C)           COMMAND REFERENCE           DIRECTORY(3C)



NAME
     directory, opendir, readdir, telldir, seekdir, rewinddir,
     closedir - directory operations

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

     DIR *opendir(filename)
     char *filename;

     struct direct *readdir(dirp)
     DIR *dirp;

     long telldir(dirp)
     DIR *dirp;

     seekdir(dirp, loc)
     DIR *dirp;
     long loc;

     rewinddir(dirp)
     DIR *dirp;

     closedir(dirp)
     DIR *dirp;

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

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

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

     Setting the position of the next readdir operation on the
     directory stream, seekdir reverts to the position 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.




Printed 3/13/89                                                 1

DIRECTORY(3C)           COMMAND REFERENCE           DIRECTORY(3C)



     The rewinddir command resets the position of the named
     directory stream to the beginning of the directory.

     Closing the named directory stream, closedir frees the
     structure associated with the DIR pointer.

EXAMPLES
     A sample code which searchs a directory for entry filename
     is:

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

CAVEATS
     Old programs which examine directories should be converted
     to use this package, as the new directory format is not
     obvious.

     The opendir command opens any file as a directory, so the
     file should be checked to make sure it is a directory by
     using stat(2).

SEE ALSO
     lseek(2), open(2), close(2), read(2), and stat(2).
























Printed 3/13/89                                                 2

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