4.3BSD-Reno/share/man/cat3/directory.0

DIRECTORY(3)		      1990		     DIRECTORY(3)



NNAAMMEE
     opendir, readdir, telldir, seekdir, rewinddir, closedir,
     dirfd - directory operations

SSYYNNOOPPSSIISS
     ##iinncclluuddee <<ssyyss//ttyyppeess..hh>>
     ##iinncclluuddee <<ddiirreenntt..hh>>

     DDIIRR **
     ooppeennddiirr((ccoonnsstt cchhaarr **ffiilleennaammee));;

     ssttrruucctt ddiirreecctt
     **rreeaaddddiirr((DDIIRR ** ddiirrpp));;

     lloonngg
     tteellllddiirr((ccoonnsstt DDIIRR **ddiirrpp));;

     vvooiidd
     sseeeekkddiirr((DDIIRR **ddiirrpp,, lloonngg lloocc));;

     vvooiidd
     rreewwiinnddddiirr((DDIIRR **ddiirrpp));;

     iinntt
     cclloosseeddiirr((DDIIRR **ddiirrpp));;

     iinntt
     ddiirrffdd((DDIIRR **ddiirrpp))

DDEESSCCRRIIPPTTIIOONN
     _O_p_e_n_d_i_r opens the directory named by _f_i_l_e_n_a_m_e and associates
     a _d_i_r_e_c_t_o_r_y _s_t_r_e_a_m with it.  _O_p_e_n_d_i_r returns a pointer to be
     used to identify the _d_i_r_e_c_t_o_r_y _s_t_r_e_a_m in subsequent opera-
     tions.  The pointer NNUULLLL is returned if _f_i_l_e_n_a_m_e cannot be
     accessed, or if it cannot _m_a_l_l_o_c(3) enough memory to hold
     the whole thing.

     _R_e_a_d_d_i_r returns a pointer to the next directory entry.  It
     returns NNUULLLL upon reaching the end of the directory or
     detecting an invalid _s_e_e_k_d_i_r operation.

     _T_e_l_l_d_i_r returns the current location associated with the
     named _d_i_r_e_c_t_o_r_y _s_t_r_e_a_m.

     _S_e_e_k_d_i_r sets the position of the next _r_e_a_d_d_i_r operation on
     the _d_i_r_e_c_t_o_r_y _s_t_r_e_a_m. The new position reverts to the one
     associated with the _d_i_r_e_c_t_o_r_y _s_t_r_e_a_m when the _t_e_l_l_d_i_r opera-
     tion was performed.  Values returned by _t_e_l_l_d_i_r are good
     only for the lifetime of the DIR pointer from which they are
     derived.  If the directory is closed and then reopened, the
     _t_e_l_l_d_i_r value may be invalidated due to undetected directory
     compaction.  It is safe to use a previous _t_e_l_l_d_i_r value



Printed 7/27/90               June				1






DIRECTORY(3)		      1990		     DIRECTORY(3)



     immediately after a call to _o_p_e_n_d_i_r and before any calls to
     _r_e_a_d_d_i_r.

     _R_e_w_i_n_d_d_i_r resets the position of the named _d_i_r_e_c_t_o_r_y _s_t_r_e_a_m
     to the beginning of the directory.

     _C_l_o_s_e_d_i_r closes the named _d_i_r_e_c_t_o_r_y _s_t_r_e_a_m and frees the
     structure associated with the DIR pointer, returning 0 on
     success.  On failure, -1 is returned and errno is set to
     indicate the error.

     _D_i_r_f_d returns the integer file descriptor associated with
     the named _d_i_r_e_c_t_o_r_y _s_t_r_e_a_m, see open(2).

     Sample code which searchs a directory for entry ``name'' is:

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

SSEEEE AALLSSOO
     open(2), close(2), read(2), lseek(2), dir(5)



























Printed 7/27/90               June				2