xref: /titanic_44/usr/src/lib/libbc/libc/gen/common/scandir.c (revision 7c478bd95313f5f23a4c958a745db2134aa03244)
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 are permitted
6  * provided that the above copyright notice and this paragraph are
7  * duplicated in all such forms and that any documentation,
8  * advertising materials, and other materials related to such
9  * distribution and use acknowledge that the software was developed
10  * by the University of California, Berkeley.  The name of the
11  * University may not be used to endorse or promote products derived
12  * from this software without specific prior written permission.
13  * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR
14  * IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED
15  * WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR A PARTICULAR PURPOSE.
16  */
17 
18 #pragma ident	"%Z%%M%	%I%	%E% SMI"
19 	  /* from UCB 5.1 85/05/30 */
20 
21 /*
22  * Copyright (c) 1983 Regents of the University of California.
23  * All rights reserved.  The Berkeley software License Agreement
24  * specifies the terms and conditions for redistribution.
25  */
26 
27 /*
28  * Scan the directory dirname calling select to make a list of selected
29  * directory entries then sort using qsort and compare routine dcomp.
30  * Returns the number of entries and a pointer to a list of pointers to
31  * struct direct (through namelist). Returns -1 if there were any errors.
32  */
33 
34 #include <sys/types.h>
35 #include <sys/stat.h>
36 #include <sys/dir.h>
37 
38 scandir(dirname, namelist, select, dcomp)
39 	char *dirname;
40 	struct direct *(*namelist[]);
41 	int (*select)(), (*dcomp)();
42 {
43 	register struct direct *d, *p, **names;
44 	register int nitems;
45 	register char *cp1, *cp2;
46 	struct stat stb;
47 	long arraysz;
48 	DIR *dirp;
49 
50 	if ((dirp = opendir(dirname)) == NULL)
51 		return(-1);
52 	if (fstat(dirp->dd_fd, &stb) < 0)
53 		return(-1);
54 
55 	/*
56 	 * estimate the array size by taking the size of the directory file
57 	 * and dividing it by a multiple of the minimum size entry.
58 	 */
59 	arraysz = (stb.st_size / 24);
60 	names = (struct direct **)malloc(arraysz * sizeof(struct direct *));
61 	if (names == NULL)
62 		return(-1);
63 
64 	nitems = 0;
65 	while ((d = readdir(dirp)) != NULL) {
66 		if (select != NULL && !(*select)(d))
67 			continue;	/* just selected names */
68 		/*
69 		 * Make a minimum size copy of the data
70 		 */
71 		p = (struct direct *)malloc(DIRSIZ(d));
72 		if (p == NULL)
73 			return(-1);
74 		p->d_ino = d->d_ino;
75 		p->d_reclen = d->d_reclen;
76 		p->d_namlen = d->d_namlen;
77 		for (cp1 = p->d_name, cp2 = d->d_name; *cp1++ = *cp2++; );
78 		/*
79 		 * Check to make sure the array has space left and
80 		 * realloc the maximum size.
81 		 */
82 		if (++nitems >= arraysz) {
83 			if (fstat(dirp->dd_fd, &stb) < 0)
84 				return(-1);	/* just might have grown */
85 			arraysz = stb.st_size / 12;
86 			names = (struct direct **)realloc((char *)names,
87 				arraysz * sizeof(struct direct *));
88 			if (names == NULL)
89 				return(-1);
90 		}
91 		names[nitems-1] = p;
92 	}
93 	closedir(dirp);
94 	if (nitems && dcomp != NULL)
95 		qsort(names, nitems, sizeof(struct direct *), dcomp);
96 	*namelist = names;
97 	return(nitems);
98 }
99 
100 /*
101  * Alphabetic order comparison routine for those who want it.
102  */
103 alphasort(d1, d2)
104 	struct direct **d1, **d2;
105 {
106 	return(strcmp((*d1)->d_name, (*d2)->d_name));
107 }
108