[unix-history] / lib / libc / gen / scandir.c

/*
 * Copyright (c) 1983 Regents of the University of California.
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. All advertising materials mentioning features or use of this software
 *    must display the following acknowledgement:
 *	This product includes software developed by the University of
 *	California, Berkeley and its contributors.
 * 4. 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 BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 */

#if defined(LIBC_SCCS) && !defined(lint)
static char sccsid[] = "@(#)scandir.c	5.10 (Berkeley) 2/23/91";
#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>
#include <stdlib.h>
#include <string.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))

int
scandir(dirname, namelist, select, dcomp)
	const char *dirname;
	struct dirent ***namelist;
	int (*select) __P((struct dirent *));
	int (*dcomp) __P((const void *, const void *));
{
	register struct dirent *d, *p, **names;
	register size_t 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.
 */
int
alphasort(d1, d2)
	const void *d1;
	const void *d2;
{
	return(strcmp((*(struct dirent **)d1)->d_name,
	    (*(struct dirent **)d2)->d_name));
}
Commit	Line	Data
15637ed4 RG	1	/*
	2	* Copyright (c) 1983 Regents of the University of California.
	3	* All rights reserved.
	4	*
	5	* Redistribution and use in source and binary forms, with or without
	6	* modification, are permitted provided that the following conditions
	7	* are met:
	8	* 1. Redistributions of source code must retain the above copyright
	9	* notice, this list of conditions and the following disclaimer.
	10	* 2. Redistributions in binary form must reproduce the above copyright
	11	* notice, this list of conditions and the following disclaimer in the
	12	* documentation and/or other materials provided with the distribution.
	13	* 3. All advertising materials mentioning features or use of this software
	14	* must display the following acknowledgement:
	15	* This product includes software developed by the University of
	16	* California, Berkeley and its contributors.
	17	* 4. Neither the name of the University nor the names of its contributors
	18	* may be used to endorse or promote products derived from this software
	19	* without specific prior written permission.
	20	*
	21	* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
	22	* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
	23	* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
	24	* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
	25	* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
	26	* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
	27	* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
	28	* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
	29	* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
	30	* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
	31	* SUCH DAMAGE.
	32	*/
	33
	34	#if defined(LIBC_SCCS) && !defined(lint)
	35	static char sccsid[] = "@(#)scandir.c 5.10 (Berkeley) 2/23/91";
	36	#endif /* LIBC_SCCS and not lint */
	37
	38	/*
	39	* Scan the directory dirname calling select to make a list of selected
	40	* directory entries then sort using qsort and compare routine dcomp.
	41	* Returns the number of entries and a pointer to a list of pointers to
	42	* struct dirent (through namelist). Returns -1 if there were any errors.
	43	*/
	44
	45	#include <sys/types.h>
	46	#include <sys/stat.h>
	47	#include <dirent.h>
	48	#include <stdlib.h>
	49	#include <string.h>
	50
	51	/*
	52	* The DIRSIZ macro gives the minimum record length which will hold
	53	* the directory entry. This requires the amount of space in struct dirent
	54	* without the d_name field, plus enough space for the name with a terminating
	55	* null byte (dp->d_namlen+1), rounded up to a 4 byte boundary.
	56	*/
	57	#undef DIRSIZ
	58	#define DIRSIZ(dp) \
	59	((sizeof (struct dirent) - (MAXNAMLEN+1)) + (((dp)->d_namlen+1 + 3) &~ 3))
	60
	61	int
	62	scandir(dirname, namelist, select, dcomp)
	63	const char *dirname;
	64	struct dirent ***namelist;
65	int (select) __P((struct dirent ));
66	int (dcomp) __P((const void , const void *));
67	{
68	register struct dirent d, p, **names;
69	register size_t nitems;
70	struct stat stb;
71	long arraysz;
72	DIR *dirp;
73
74	if ((dirp = opendir(dirname)) == NULL)
75	return(-1);
76	if (fstat(dirp->dd_fd, &stb) < 0)
77	return(-1);
78
79	/*
80	* estimate the array size by taking the size of the directory file
81	* and dividing it by a multiple of the minimum size entry.
82	*/
83	arraysz = (stb.st_size / 24);
84	names = (struct dirent *)malloc(arraysz sizeof(struct dirent *));
85	if (names == NULL)
86	return(-1);
87
88	nitems = 0;
89	while ((d = readdir(dirp)) != NULL) {
90	if (select != NULL && !(*select)(d))
91	continue; /* just selected names */
92	/*
93	* Make a minimum size copy of the data
94	*/
95	p = (struct dirent *)malloc(DIRSIZ(d));
96	if (p == NULL)
97	return(-1);
98	p->d_ino = d->d_ino;
99	p->d_reclen = d->d_reclen;
100	p->d_namlen = d->d_namlen;
101	bcopy(d->d_name, p->d_name, p->d_namlen + 1);
102	/*
103	* Check to make sure the array has space left and
104	* realloc the maximum size.
105	*/
106	if (++nitems >= arraysz) {
107	if (fstat(dirp->dd_fd, &stb) < 0)
108	return(-1); /* just might have grown */
109	arraysz = stb.st_size / 12;
110	names = (struct dirent *)realloc((char )names,
111	arraysz * sizeof(struct dirent *));
112	if (names == NULL)
113	return(-1);
114	}
115	names[nitems-1] = p;
116	}
117	closedir(dirp);
118	if (nitems && dcomp != NULL)
119	qsort(names, nitems, sizeof(struct dirent *), dcomp);
120	*namelist = names;
121	return(nitems);
122	}
123
124	/*
125	* Alphabetic order comparison routine for those who want it.
126	*/
127	int
128	alphasort(d1, d2)
129	const void *d1;
130	const void *d2;
131	{
132	return(strcmp(((struct dirent *)d1)->d_name,
133	((struct dirent *)d2)->d_name));
134	}