directory(3C)                                       directory(3C)



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

SYNOPSIS (AT&T System V)
     #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;

     closedir(dirp)
     DIR *dirp;

SYNOPSIS (4 BSD)
     #include <sys/dir.h>

     DIR *opendir(filename)
     char *filename;

     struct direct *readdir(dirp)
     DIR *dirp;

     long telldir(dirp)
     DIR *dirp;

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

     void rewinddir(dirp)
     DIR *dirp;

     void closedir(dirp)
     DIR *dirp;

DESCRIPTION
     Opendir opens the directory named by filename and associates
     a directory stream with it.  Opendir returns a pointer to be



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directory(3C)                                       directory(3C)



     used to identify the directory stream in subsequent opera-
     tions.  The pointer NULL is returned if filename cannot be
     accessed or is not a directory, or if it cannot malloc(3C)
     enough memory to hold a DIR structure or a buffer for the
     directory entries.

     Readdir returns a pointer to the next directory entry.  No
     inactive entries are returned.  It returns NULL upon reach-
     ing 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 opera-
     tion from which loc was obtained 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.

     The following errors can occur as a result of these opera-
     tions.

     opendir:

     [EACCES]       A component of filename denies search permis-
                    sion.

     [EFAULT]       Filename points outside the allocated address
                    space.

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

     [ENAMETOOLONG] The length of the filename argument exceeds
                    {PATH_MAX}, or a pathname component is longer
                    that {NAME_MAX}  (see pathconf(2)).

     [ENFILE]       The maximum number of file descriptors in the
                    system are currently open.

     [ENOENT]       The named directory does not exist or



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directory(3C)                                       directory(3C)



                    filename points to an empty string.

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


     readdir:

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

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


     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->d_name, name ) == 0 )
                    {
                    closedir( dirp );
                    return FOUND;
                    }
          closedir( dirp );
          return NOT_FOUND;


SEE ALSO
     open(2), close(2), read(2), lseek(2), getdirentries(2),
     dir(4)

















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