/*
 * Copyright (c) 1983 Regents of the University of California.
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms are permitted provided
 * that: (1) source distributions retain this entire copyright notice and
 * comment, and (2) distributions including binaries display the following
 * acknowledgement:  ``This product includes software developed by the
 * University of California, Berkeley and its contributors'' in the
 * documentation or other materials provided with the distribution and in
 * all advertising materials mentioning features or use of this software.
 * Neither the name of the University nor the names of its contributors may
 * be used to endorse or promote products derived from this software without
 * specific prior written permission.
 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR IMPLIED
 * WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED WARRANTIES OF
 * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
 */

/*
	$Disclaimer: 
 * Permission to use, copy, modify, and distribute this software and its 
 * documentation for any purpose is hereby granted without fee, 
 * provided that the above copyright notice appear in all copies and that 
 * both that copyright notice, this permission notice, and the following 
 * disclaimer appear in supporting documentation, and that the names of 
 * IBM, Carnegie Mellon University, and other copyright holders, not be 
 * used in advertising or publicity pertaining to distribution of the software 
 * without specific, written prior permission.
 * 
 * IBM, CARNEGIE MELLON UNIVERSITY, AND THE OTHER COPYRIGHT HOLDERS 
 * DISCLAIM ALL WARRANTIES WITH REGARD TO THIS SOFTWARE, INCLUDING 
 * ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS.  IN NO EVENT 
 * SHALL IBM, CARNEGIE MELLON UNIVERSITY, OR ANY OTHER COPYRIGHT HOLDER 
 * BE LIABLE FOR ANY SPECIAL, INDIRECT OR CONSEQUENTIAL DAMAGES OR ANY 
 * DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, 
 * WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS 
 * ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE 
 * OF THIS SOFTWARE.
 *  $
*/

#ifndef NORCSID
#define NORCSID
static char rcsid[]="$Header: /afs/cs.cmu.edu/project/atk-dist/auis-6.3/ossupport/hpx/RCS/scandir.c,v 1.3 1992/12/15 21:16:51 rr2b R6tape $";
#endif


#if defined(LIBC_SCCS) && !defined(lint)
static char sccsid[] = "@(#)scandir.c	5.9 (Berkeley) 6/24/90";
#endif /* LIBC_SCCS and not lint */

/*
 * Scan the directory dirname calling select to make a list of selected
 * directory entries then sort using qsort and compare routine dcomp.
 * Returns the number of entries and a pointer to a list of pointers to
 * struct dirent (through namelist). Returns -1 if there were any errors.
 */

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

/*
 * The DIRSIZ macro gives the minimum record length which will hold
 * the directory entry.  This requires the amount of space in struct dirent
 * without the d_name field, plus enough space for the name with a terminating
 * null byte (dp->d_namlen+1), rounded up to a 4 byte boundary.
 */
#undef DIRSIZ
#define DIRSIZ(dp) \
    ((sizeof (struct dirent) - (MAXNAMLEN+1)) + (((dp)->d_namlen+1 + 3) &~ 3))

#ifdef hpux
#define bcopy(src, dst, length) memmove(dst, src, length)
#endif /* hpux */

scandir(dirname, namelist, select, dcomp)
	char *dirname;
	struct dirent ***namelist;
	int (*select)(), (*dcomp)();
{
	register struct dirent *d, *p, **names;
	register int nitems;
	struct stat stb;
	long arraysz;
	DIR *dirp;

	if ((dirp = opendir(dirname)) == NULL)
		return(-1);
	if (fstat(dirp->dd_fd, &stb) < 0)
		return(-1);

	/*
	 * estimate the array size by taking the size of the directory file
	 * and dividing it by a multiple of the minimum size entry. 
	 */
	arraysz = (stb.st_size / 24);
	names = (struct dirent **)malloc(arraysz * sizeof(struct dirent *));
	if (names == NULL)
		return(-1);

	nitems = 0;
	while ((d = readdir(dirp)) != NULL) {
		if (select != NULL && !(*select)(d))
			continue;	/* just selected names */
		/*
		 * Make a minimum size copy of the data
		 */
		p = (struct dirent *)malloc(DIRSIZ(d));
		if (p == NULL)
			return(-1);
		p->d_ino = d->d_ino;
		p->d_reclen = d->d_reclen;
		p->d_namlen = d->d_namlen;
		bcopy(d->d_name, p->d_name, p->d_namlen + 1);
		/*
		 * Check to make sure the array has space left and
		 * realloc the maximum size.
		 */
		if (++nitems >= arraysz) {
			if (fstat(dirp->dd_fd, &stb) < 0)
				return(-1);	/* just might have grown */
			arraysz = stb.st_size / 12;
			names = (struct dirent **)realloc((char *)names,
				arraysz * sizeof(struct dirent *));
			if (names == NULL)
				return(-1);
		}
		names[nitems-1] = p;
	}
	closedir(dirp);
	if (nitems && dcomp != NULL)
		qsort(names, nitems, sizeof(struct dirent *), dcomp);
	*namelist = names;
	return(nitems);
}

/*
 * Alphabetic order comparison routine for those who want it.
 */
alphasort(d1, d2)
	void *d1, *d2;
{
	return(strcmp((*(struct dirent **)d1)->d_name,
	    (*(struct dirent **)d2)->d_name));
}