1 /* $NetBSD: dir_forest.c,v 1.1.1.1 2009/06/23 10:08:59 tron Exp $ */
2
3 /*++
4 /* NAME
5 /* dir_forest 3
6 /* SUMMARY
7 /* file name to directory forest
8 /* SYNOPSIS
9 /* #include <dir_forest.h>
10 /*
11 /* char *dir_forest(buf, path, depth)
12 /* VSTRING *buf;
13 /* const char *path;
14 /* int depth;
15 /* DESCRIPTION
16 /* This module implements support for directory forests: a file
17 /* organization that introduces one or more levels of intermediate
18 /* subdirectories in order to reduce the number of files per directory.
19 /*
20 /* dir_forest() maps a file basename to a directory forest and
21 /* returns the resulting string: file name "abcd" becomes "a/b/"
22 /* and so on. The number of subdirectory levels is adjustable.
23 /*
24 /* Arguments:
25 /* .IP buf
26 /* A buffer that is overwritten with the result. The result
27 /* ends in "/" and is null terminated. If a null pointer is
28 /* specified, the result is written to a private buffer that
29 /* is overwritten upon each call.
30 /* .IP path
31 /* A null-terminated string of printable characters. Characters
32 /* special to the file system are not permitted.
33 /* The first subdirectory is named after the first character
34 /* in \fIpath\fR, and so on. When the path is shorter than the
35 /* desired number of subdirectory levels, directory names
36 /* of '_' (underscore) are used as replacement.
37 /* .IP depth
38 /* The desired number of subdirectory levels.
39 /* DIAGNOSTICS
40 /* Panic: interface violations. Fatal error: out of memory.
41 /* LICENSE
42 /* .ad
43 /* .fi
44 /* The Secure Mailer license must be distributed with this software.
45 /* AUTHOR(S)
46 /* Wietse Venema
47 /* IBM T.J. Watson Research
48 /* P.O. Box 704
49 /* Yorktown Heights, NY 10598, USA
50 /*--*/
51
52 /* System library. */
53
54 #include <sys_defs.h>
55 #include <ctype.h>
56
57 /* Utility library. */
58
59 #include "msg.h"
60 #include "dir_forest.h"
61
62 /* dir_forest - translate base name to directory forest */
63
dir_forest(VSTRING * buf,const char * path,int depth)64 char *dir_forest(VSTRING *buf, const char *path, int depth)
65 {
66 const char *myname = "dir_forest";
67 static VSTRING *private_buf = 0;
68 int n;
69 const char *cp;
70 int ch;
71
72 /*
73 * Sanity checks.
74 */
75 if (*path == 0)
76 msg_panic("%s: empty path", myname);
77 if (depth < 1)
78 msg_panic("%s: depth %d", myname, depth);
79
80 /*
81 * Your buffer or mine?
82 */
83 if (buf == 0) {
84 if (private_buf == 0)
85 private_buf = vstring_alloc(1);
86 buf = private_buf;
87 }
88
89 /*
90 * Generate one or more subdirectory levels, depending on the pathname
91 * contents. When the pathname is short, use underscores instead.
92 * Disallow non-printable characters or characters that are special to
93 * the file system.
94 */
95 VSTRING_RESET(buf);
96 for (cp = path, n = 0; n < depth; n++) {
97 if ((ch = *cp) == 0) {
98 ch = '_';
99 } else {
100 if (!ISPRINT(ch) || ch == '.' || ch == '/')
101 msg_panic("%s: invalid pathname: %s", myname, path);
102 cp++;
103 }
104 VSTRING_ADDCH(buf, ch);
105 VSTRING_ADDCH(buf, '/');
106 }
107 VSTRING_TERMINATE(buf);
108
109 if (msg_verbose > 1)
110 msg_info("%s: %s -> %s", myname, path, vstring_str(buf));
111 return (vstring_str(buf));
112 }
113