xref: /csrg-svn/lib/libc/gen/scandir.c (revision 21357)
1*21357Sdist /*
2*21357Sdist  * Copyright (c) 1983 Regents of the University of California.
3*21357Sdist  * All rights reserved.  The Berkeley software License Agreement
4*21357Sdist  * specifies the terms and conditions for redistribution.
5*21357Sdist  */
6*21357Sdist 
713582Ssam #ifndef lint
8*21357Sdist static char sccsid[] = "@(#)scandir.c	5.1 (Berkeley) 05/30/85";
9*21357Sdist #endif not lint
1013582Ssam 
119609Sralph /*
129609Sralph  * Scan the directory dirname calling select to make a list of selected
139609Sralph  * directory entries then sort using qsort and compare routine dcomp.
149609Sralph  * Returns the number of entries and a pointer to a list of pointers to
159609Sralph  * struct direct (through namelist). Returns -1 if there were any errors.
169609Sralph  */
179609Sralph 
189609Sralph #include <sys/types.h>
199609Sralph #include <sys/stat.h>
2013582Ssam #include <sys/dir.h>
219609Sralph 
229609Sralph scandir(dirname, namelist, select, dcomp)
239609Sralph 	char *dirname;
249609Sralph 	struct direct *(*namelist[]);
259609Sralph 	int (*select)(), (*dcomp)();
269609Sralph {
279609Sralph 	register struct direct *d, *p, **names;
289609Sralph 	register int nitems;
299609Sralph 	register char *cp1, *cp2;
309609Sralph 	struct stat stb;
319609Sralph 	long arraysz;
329609Sralph 	DIR *dirp;
339609Sralph 
349609Sralph 	if ((dirp = opendir(dirname)) == NULL)
359609Sralph 		return(-1);
369609Sralph 	if (fstat(dirp->dd_fd, &stb) < 0)
379609Sralph 		return(-1);
389609Sralph 
399609Sralph 	/*
409609Sralph 	 * estimate the array size by taking the size of the directory file
419609Sralph 	 * and dividing it by a multiple of the minimum size entry.
429609Sralph 	 */
439609Sralph 	arraysz = (stb.st_size / 24);
449609Sralph 	names = (struct direct **)malloc(arraysz * sizeof(struct direct *));
459609Sralph 	if (names == NULL)
469609Sralph 		return(-1);
479609Sralph 
489609Sralph 	nitems = 0;
499609Sralph 	while ((d = readdir(dirp)) != NULL) {
509609Sralph 		if (select != NULL && !(*select)(d))
519609Sralph 			continue;	/* just selected names */
529609Sralph 		/*
539609Sralph 		 * Make a minimum size copy of the data
549609Sralph 		 */
559609Sralph 		p = (struct direct *)malloc(DIRSIZ(d));
569609Sralph 		if (p == NULL)
579609Sralph 			return(-1);
589609Sralph 		p->d_ino = d->d_ino;
599609Sralph 		p->d_reclen = d->d_reclen;
609609Sralph 		p->d_namlen = d->d_namlen;
619609Sralph 		for (cp1 = p->d_name, cp2 = d->d_name; *cp1++ = *cp2++; );
629609Sralph 		/*
639609Sralph 		 * Check to make sure the array has space left and
649609Sralph 		 * realloc the maximum size.
659609Sralph 		 */
669609Sralph 		if (++nitems >= arraysz) {
6715661Sralph 			if (fstat(dirp->dd_fd, &stb) < 0)
6815661Sralph 				return(-1);	/* just might have grown */
6915661Sralph 			arraysz = stb.st_size / 12;
709609Sralph 			names = (struct direct **)realloc((char *)names,
7115661Sralph 				arraysz * sizeof(struct direct *));
729609Sralph 			if (names == NULL)
739609Sralph 				return(-1);
749609Sralph 		}
759609Sralph 		names[nitems-1] = p;
769609Sralph 	}
779609Sralph 	closedir(dirp);
789609Sralph 	if (nitems && dcomp != NULL)
799609Sralph 		qsort(names, nitems, sizeof(struct direct *), dcomp);
809609Sralph 	*namelist = names;
819609Sralph 	return(nitems);
829609Sralph }
839609Sralph 
849609Sralph /*
859609Sralph  * Alphabetic order comparison routine for those who want it.
869609Sralph  */
879609Sralph alphasort(d1, d2)
889609Sralph 	struct direct **d1, **d2;
899609Sralph {
909609Sralph 	return(strcmp((*d1)->d_name, (*d2)->d_name));
919609Sralph }
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