from scratch; write to /dev/tty if possible, block interrupts
[unix-history] / usr / src / lib / libc / gen / scandir.c
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1/*
2 * Copyright (c) 1983 Regents of the University of California.
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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.
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16 */
17
2ce81398 18#if defined(LIBC_SCCS) && !defined(lint)
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19static char sccsid[] = "@(#)scandir.c 5.3 (Berkeley) %G%";
20#endif /* LIBC_SCCS and not lint */
455b164d 21
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22/*
23 * Scan the directory dirname calling select to make a list of selected
24 * directory entries then sort using qsort and compare routine dcomp.
25 * Returns the number of entries and a pointer to a list of pointers to
26 * struct direct (through namelist). Returns -1 if there were any errors.
27 */
28
29#include <sys/types.h>
30#include <sys/stat.h>
455b164d 31#include <sys/dir.h>
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32
33scandir(dirname, namelist, select, dcomp)
34 char *dirname;
35 struct direct *(*namelist[]);
36 int (*select)(), (*dcomp)();
37{
38 register struct direct *d, *p, **names;
39 register int nitems;
40 register char *cp1, *cp2;
41 struct stat stb;
42 long arraysz;
43 DIR *dirp;
44
45 if ((dirp = opendir(dirname)) == NULL)
46 return(-1);
47 if (fstat(dirp->dd_fd, &stb) < 0)
48 return(-1);
49
50 /*
51 * estimate the array size by taking the size of the directory file
52 * and dividing it by a multiple of the minimum size entry.
53 */
54 arraysz = (stb.st_size / 24);
55 names = (struct direct **)malloc(arraysz * sizeof(struct direct *));
56 if (names == NULL)
57 return(-1);
58
59 nitems = 0;
60 while ((d = readdir(dirp)) != NULL) {
61 if (select != NULL && !(*select)(d))
62 continue; /* just selected names */
63 /*
64 * Make a minimum size copy of the data
65 */
66 p = (struct direct *)malloc(DIRSIZ(d));
67 if (p == NULL)
68 return(-1);
69 p->d_ino = d->d_ino;
70 p->d_reclen = d->d_reclen;
71 p->d_namlen = d->d_namlen;
72 for (cp1 = p->d_name, cp2 = d->d_name; *cp1++ = *cp2++; );
73 /*
74 * Check to make sure the array has space left and
75 * realloc the maximum size.
76 */
77 if (++nitems >= arraysz) {
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78 if (fstat(dirp->dd_fd, &stb) < 0)
79 return(-1); /* just might have grown */
80 arraysz = stb.st_size / 12;
38cb3a9a 81 names = (struct direct **)realloc((char *)names,
71120ea4 82 arraysz * sizeof(struct direct *));
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83 if (names == NULL)
84 return(-1);
85 }
86 names[nitems-1] = p;
87 }
88 closedir(dirp);
89 if (nitems && dcomp != NULL)
90 qsort(names, nitems, sizeof(struct direct *), dcomp);
91 *namelist = names;
92 return(nitems);
93}
94
95/*
96 * Alphabetic order comparison routine for those who want it.
97 */
98alphasort(d1, d2)
99 struct direct **d1, **d2;
100{
101 return(strcmp((*d1)->d_name, (*d2)->d_name));
102}