directory(3X)              DG/UX 4.30               directory(3X)



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

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

          DIR *opendir (filename)
          char *filename;

          struct dirent *readdir (dirp)
          DIR *dirp;

          long telldir (dirp)
          DIR *dirp;

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

          void rewinddir (dirp)
          DIR *dirp;

          int closedir(dirp)
          DIR *dirp;

        Alternate Syntax
          #include <sys/dir.h>
          struct direct *readdir (dirp)
          DIR *dirp;
          (All other function interfaces remain the same.)

     DESCRIPTION
          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 is not a directory, or if it cannot allocate
          enough memory to hold a DIR structure or a buffer for the
          directory entries.

          Readdir returns a pointer to the next active directory
          entry.  No inactive entries are returned.  It returns NULL
          upon reaching the end of the directory or upon detecting an
          invalid location in the directory.

          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



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     directory(3X)              DG/UX 4.30               directory(3X)



          associated with the directory stream when the telldir
          operation from which loc was obtained was performed.  Values
          returned by telldir are good only if the directory has not
          changed due to compaction or expansion.  This is not a
          problem with System V, but it can be with DG/UX and some
          file system types.

          Rewinddir resets the position of the named directory stream
          to the beginning of the directory.

          Closedir closes the named directory stream and frees the DIR
          structure.

          The following errors can occur as a result of these
          operations.

          opendir:

          [ENOTDIR]      A component of filename is not a directory.

          [EACCES]       A component of filename denies search
                         permission.

          [EMFILE]       The maximum number of file descriptors are
                         currently open.

          [EFAULT]       Filename points outside the allocated address
                         space.


          readdir:

          [ENOENT]       The current file pointer for the directory is
                         not located at a valid entry.

          [EBADF]        The file descriptor determined by the DIR
                         stream is no longer valid.  This results if
                         the DIR stream has been closed.


          telldir, seekdir, and closedir:

          [EBADF]        The file descriptor determined by the DIR
                         stream is no longer valid.  This results if
                         the DIR stream has been closed.

     EXAMPLE
          Sample code which searches a directory for entry name:

               dirp = opendir( "." );
               while ( (dp = readdir( dirp )) != NULL )
                    if ( strcmp( dp->dname, name ) == 0 )



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     directory(3X)              DG/UX 4.30               directory(3X)



                         {
                         closedir( dirp );
                         return FOUND;
                         }
               closedir( dirp );
               return NOTFOUND;


     SEE ALSO
          getdents(2), dirent(4).

     WARNINGS
          Rewinddir is implemented as a macro, so its function address
          cannot be taken.









































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