/*
 * CDDL HEADER START
 *
 * The contents of this file are subject to the terms of the
 * Common Development and Distribution License, Version 1.0 only
 * (the "License").  You may not use this file except in compliance
 * with the License.
 *
 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
 * or http://www.opensolaris.org/os/licensing.
 * See the License for the specific language governing permissions
 * and limitations under the License.
 *
 * When distributing Covered Code, include this CDDL HEADER in each
 * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
 * If applicable, add the following below this CDDL HEADER, with the
 * fields enclosed by brackets "[]" replaced with your own identifying
 * information: Portions Copyright [yyyy] [name of copyright owner]
 *
 * CDDL HEADER END
 */
/*
 * Copyright 1997 Sun Microsystems, Inc.  All rights reserved.
 * Use is subject to license terms.
 */

/*      Copyright (c) 1984, 1986, 1987, 1988, 1989 AT&T */
/*        All Rights Reserved   */

/*
 * University Copyright- Copyright (c) 1982, 1986, 1988
 * The Regents of the University of California
 * All Rights Reserved
 *
 * University Acknowledgment- Portions of this document are derived from
 * software developed by the University of California, Berkeley, and its
 * contributors.
 */

/*LINTLIBRARY*/

/*
 * 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 direct (through namelist). Returns -1 if there were any errors.
 */

#include <sys/types.h>
#include <sys/stat.h>
#include <sys/dir.h>
#include <errno.h>
#include <limits.h>
#include <stdlib.h>
#include <string.h>

/*
 * The macro DIRSIZ(dp) gives an amount of space required to represent
 * a directory entry.  For any directory entry dp->d_reclen >= DIRSIZ(dp).
 * Specific filesystem types may use this use this macro to construct the value
 * for d_reclen.
 */
#undef DIRSIZ
#define DIRSIZ(dp)  \
        ((sizeof (struct direct) - sizeof ((dp)->d_name) + \
        (strlen((dp)->d_name)+1) + 3) & ~3)

#if !defined(_LP64)
int
scandir64(char *dirname, struct direct64 *(*namelist[]),
    int (*select)(struct direct64 *),
    int (*dcomp)(struct direct64 **, struct direct64 **))
{
        struct direct64 *d, *p, **names;
        int nitems;
        char *cp1, *cp2;
        struct stat64 stb;
        long arraysz;
        DIR *dirp;

        if ((dirp = opendir(dirname)) == NULL)
                return (-1);
        if (fstat64(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 direct64 **)malloc(arraysz *
                sizeof (struct direct64 *));
        if (names == NULL)
                return (-1);

        nitems = 0;
        while ((d = readdir64(dirp)) != NULL) {
                if (select != NULL && !(*select)(d))
                        continue;       /* just selected names */
                /*
                 * Make a minimum size copy of the data
                 */
                p = (struct direct64 *)malloc(DIRSIZ64(d));
                if (p == NULL)
                        return (-1);
                p->d_ino = d->d_ino;
                p->d_reclen = d->d_reclen;
                p->d_namlen = d->d_namlen;
                for (cp1 = p->d_name, cp2 = d->d_name; *cp1++ = *cp2++; )
                        ;
                /*
                 * Check to make sure the array has space left and
                 * realloc the maximum size.
                 */
                if (++nitems >= arraysz) {
                        if (fstat64(dirp->dd_fd, &stb) < 0)
                                return (-1);    /* just might have grown */
                        arraysz = stb.st_size / 12;
                        names = (struct direct64 **)realloc((char *)names,
                                arraysz * sizeof (struct direct64 *));
                        if (names == NULL)
                                return (-1);
                }
                names[nitems-1] = p;
        }
        (void) closedir(dirp);
        if (nitems && dcomp != NULL)
                qsort(names, nitems, sizeof (struct direct64 *),
                        (int(*)(const void *, const void *)) dcomp);
        *namelist = names;
        return (nitems);
}
#endif


int
scandir(char *dirname, struct direct *(*namelist[]),
    int (*select)(struct direct *),
    int (*dcomp)(struct direct **, struct direct **))
{
        struct direct *d, *p, **names;
        int nitems;
        char *cp1, *cp2;
        struct stat64 stb;
        long arraysz;
        DIR *dirp;

        if ((dirp = opendir(dirname)) == NULL)
                return (-1);
        if (fstat64(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.
         */
        if (stb.st_size > SSIZE_MAX) {
                errno = EOVERFLOW;
                return (-1);
        }
        arraysz = (stb.st_size / 24);

        names = (struct direct **)malloc(arraysz * sizeof (struct direct *));
        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 direct *)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;
                for (cp1 = p->d_name, cp2 = d->d_name; *cp1++ = *cp2++; )
                        ;
                /*
                 * Check to make sure the array has space left and
                 * realloc the maximum size.
                 */
                if (++nitems >= arraysz) {
                        if (fstat64(dirp->dd_fd, &stb) < 0)
                                return (-1);    /* just might have grown */
                        arraysz = stb.st_size / 12;
                        names = (struct direct **)realloc((char *)names,
                                arraysz * sizeof (struct direct *));
                        if (names == NULL)
                                return (-1);
                }
                names[nitems-1] = p;
        }
        (void) closedir(dirp);
        if (nitems && dcomp != NULL)
                qsort(names, nitems, sizeof (struct direct *),
                        (int(*)(const void *, const void *)) dcomp);
        *namelist = names;
        return (nitems);
}

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

#if !defined(_LP64)
int
alphasort64(struct direct64 **d1, struct direct64 **d2)
{
        return (strcmp((*d1)->d_name, (*d2)->d_name));
}
#endif