xref: /csrg-svn/lib/libc/gen/scandir.c (revision 15661)
113582Ssam #ifndef lint
2*15661Sralph static char sccsid[] = "@(#)scandir.c	4.3 (Berkeley) 12/05/83";
313582Ssam #endif
413582Ssam 
59609Sralph /*
69609Sralph  * Scan the directory dirname calling select to make a list of selected
79609Sralph  * directory entries then sort using qsort and compare routine dcomp.
89609Sralph  * Returns the number of entries and a pointer to a list of pointers to
99609Sralph  * struct direct (through namelist). Returns -1 if there were any errors.
109609Sralph  */
119609Sralph 
129609Sralph #include <sys/types.h>
139609Sralph #include <sys/stat.h>
1413582Ssam #include <sys/dir.h>
159609Sralph 
169609Sralph scandir(dirname, namelist, select, dcomp)
179609Sralph 	char *dirname;
189609Sralph 	struct direct *(*namelist[]);
199609Sralph 	int (*select)(), (*dcomp)();
209609Sralph {
219609Sralph 	register struct direct *d, *p, **names;
229609Sralph 	register int nitems;
239609Sralph 	register char *cp1, *cp2;
249609Sralph 	struct stat stb;
259609Sralph 	long arraysz;
269609Sralph 	DIR *dirp;
279609Sralph 
289609Sralph 	if ((dirp = opendir(dirname)) == NULL)
299609Sralph 		return(-1);
309609Sralph 	if (fstat(dirp->dd_fd, &stb) < 0)
319609Sralph 		return(-1);
329609Sralph 
339609Sralph 	/*
349609Sralph 	 * estimate the array size by taking the size of the directory file
359609Sralph 	 * and dividing it by a multiple of the minimum size entry.
369609Sralph 	 */
379609Sralph 	arraysz = (stb.st_size / 24);
389609Sralph 	names = (struct direct **)malloc(arraysz * sizeof(struct direct *));
399609Sralph 	if (names == NULL)
409609Sralph 		return(-1);
419609Sralph 
429609Sralph 	nitems = 0;
439609Sralph 	while ((d = readdir(dirp)) != NULL) {
449609Sralph 		if (select != NULL && !(*select)(d))
459609Sralph 			continue;	/* just selected names */
469609Sralph 		/*
479609Sralph 		 * Make a minimum size copy of the data
489609Sralph 		 */
499609Sralph 		p = (struct direct *)malloc(DIRSIZ(d));
509609Sralph 		if (p == NULL)
519609Sralph 			return(-1);
529609Sralph 		p->d_ino = d->d_ino;
539609Sralph 		p->d_reclen = d->d_reclen;
549609Sralph 		p->d_namlen = d->d_namlen;
559609Sralph 		for (cp1 = p->d_name, cp2 = d->d_name; *cp1++ = *cp2++; );
569609Sralph 		/*
579609Sralph 		 * Check to make sure the array has space left and
589609Sralph 		 * realloc the maximum size.
599609Sralph 		 */
609609Sralph 		if (++nitems >= arraysz) {
61*15661Sralph 			if (fstat(dirp->dd_fd, &stb) < 0)
62*15661Sralph 				return(-1);	/* just might have grown */
63*15661Sralph 			arraysz = stb.st_size / 12;
649609Sralph 			names = (struct direct **)realloc((char *)names,
65*15661Sralph 				arraysz * sizeof(struct direct *));
669609Sralph 			if (names == NULL)
679609Sralph 				return(-1);
689609Sralph 		}
699609Sralph 		names[nitems-1] = p;
709609Sralph 	}
719609Sralph 	closedir(dirp);
729609Sralph 	if (nitems && dcomp != NULL)
739609Sralph 		qsort(names, nitems, sizeof(struct direct *), dcomp);
749609Sralph 	*namelist = names;
759609Sralph 	return(nitems);
769609Sralph }
779609Sralph 
789609Sralph /*
799609Sralph  * Alphabetic order comparison routine for those who want it.
809609Sralph  */
819609Sralph alphasort(d1, d2)
829609Sralph 	struct direct **d1, **d2;
839609Sralph {
849609Sralph 	return(strcmp((*d1)->d_name, (*d2)->d_name));
859609Sralph }
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