Path: utzoo!utgpu!jarvis.csri.toronto.edu!cs.utexas.edu!tut.cis.ohio-state.edu!ucbvax!hplabs!hpfcso!hpfcdc!rer
From: rer@hpfcdc.HP.COM (Rob Robason)
Newsgroups: comp.sys.hp
Subject: Re: DIRECTORY (3C) strangeness
Message-ID: <5570336@hpfcdc.HP.COM>
Date: 29 Nov 89 20:40:25 GMT
References: <616@mmlai.UUCP>
Organization: HP Ft. Collins, Co.
Lines: 92

> System: HP-UX 6.5 B 9000/370

> Has anybody else used this code and been able to extract file names in
> alphabetical order?

The 6.5 release has an undocumented function in libc called scandir and
another called alphasort.  These derive from BSD and will read an entire
directory and sort it alphabetically.  Note that use of scandir and
alphasort is not yet supported on the 800, not for any particular reason
-- just that it got into the 300 more by accident than plan.  Attached
is the reference page for scandir.

HP hasn't tested the scandir function in 6.5, and since it's not
documented it is officially "unsupported", but the sample application
shown at the bottom of this response does seem to work.

> I really need the filenames in order...  Thanks in advance.

> Tony Burzio               *  SNOW!  On Thanksgiving?  Ski time!

Rob Robason		* Went skiing yesterday at Keystone -- GREAT!!
Not speaking for HP, just trying to be helpful
########################################################################

     SCANDIR(3)	    (September 17, 1985)	    SCANDIR(3)

     NAME
	  scandir, alphasort - scan a directory

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

	  scandir(dirname, namelist, select, compar)
	  char *dirname;
	  struct direct *(*namelist[]);
	  int (*select)();
	  int (*compar)();

	  alphasort(d1, d2)
	  struct direct **d1, **d2;

     DESCRIPTION
	  Scandir reads the directory dirname and builds an array of
	  pointers to directory entries using malloc(3).  It returns
	  the number of entries in the array and a pointer to the
	  array through namelist.

	  The select parameter is a pointer to a user supplied
	  subroutine which is called by scandir to select which
	  entries are to be included in the array.  The select routine
	  is passed a pointer to a directory entry and should return a
	  non-zero value if the directory entry is to be included in
	  the array.  If select is null, then all the directory
	  entries will be included.

	  The compar parameter is a pointer to a user supplied
	  subroutine which is passed to qsort(3) to sort the completed
	  array. If this pointer is null, the array is not sorted.
	  Alphasort is a routine which can be used for the compar
	  parameter to sort the array alphabetically.

	  The memory allocated for the array can be deallocated with
	  free (see malloc(3)) by freeing each pointer in the array
	  and the array itself.

     SEE ALSO
	  directory(3), malloc(3), qsort(3), dir(5)

     DIAGNOSTICS
	  Returns -1 if the directory cannot be opened for reading or
	  if malloc(3) cannot allocate enough memory to hold all the
	  data structures.

     Hewlett-Packard Company	   - 1 -		  Nov 29, 1989

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

int alphasort();

main()
{
	struct direct **namelist;

	scandir(".", &namelist, 0, alphasort);
	while (*namelist) {
		printf("%s\n", (*namelist)->d_name);
		namelist++;
	}
}