1 /* Adapted from NetBSB libc by Dieter Baron */
2
3 /* NetBSD: gettemp.c,v 1.13 2003/12/05 00:57:36 uebayasi Exp */
4
5 /*
6 * Copyright (c) 1987, 1993
7 * The Regents of the University of California. All rights reserved.
8 *
9 * Redistribution and use in source and binary forms, with or without
10 * modification, are permitted provided that the following conditions
11 * are met:
12 * 1. Redistributions of source code must retain the above copyright
13 * notice, this list of conditions and the following disclaimer.
14 * 2. Redistributions in binary form must reproduce the above copyright
15 * notice, this list of conditions and the following disclaimer in the
16 * documentation and/or other materials provided with the distribution.
17 * 3. Neither the name of the University nor the names of its contributors
18 * may be used to endorse or promote products derived from this software
19 * without specific prior written permission.
20 *
21 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
22 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
23 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
24 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
25 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
26 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
27 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
28 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
29 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
30 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
31 * SUCH DAMAGE.
32 */
33
34 #include <sys/types.h>
35 #include <sys/stat.h>
36
37 #include <assert.h>
38 #include <ctype.h>
39 #include <errno.h>
40 #include <fcntl.h>
41 #ifdef _WIN32
42 #include <io.h>
43 #endif
44 #include <stdio.h>
45 #include <stdlib.h>
46
47 #ifndef O_BINARY
48 #define O_BINARY 0
49 #endif
50
51
52 int
53 _zip_mkstemp(char *path)
54 {
55 #ifdef _WIN32
56 int ret;
57 ret = _creat(_mktemp(path), _S_IREAD|_S_IWRITE);
58 if (ret == -1) {
59 return 0;
60 } else {
61 return ret;
62 }
63 #else
64 int fd;
65 char *start, *trv;
66 struct stat sbuf;
67 pid_t pid;
68
69 /* To guarantee multiple calls generate unique names even if
70 the file is not created. 676 different possibilities with 7
71 or more X's, 26 with 6 or less. */
72 static char xtra[2] = "aa";
73 int xcnt = 0;
74
75 pid = getpid();
76
77 /* Move to end of path and count trailing X's. */
78 for (trv = path; *trv; ++trv)
79 if (*trv == 'X')
80 xcnt++;
81 else
82 xcnt = 0;
83
84 /* Use at least one from xtra. Use 2 if more than 6 X's. */
85 if (*(trv - 1) == 'X')
86 *--trv = xtra[0];
87 if (xcnt > 6 && *(trv - 1) == 'X')
88 *--trv = xtra[1];
89
90 /* Set remaining X's to pid digits with 0's to the left. */
91 while (*--trv == 'X') {
92 *trv = (pid % 10) + '0';
93 pid /= 10;
94 }
95
96 /* update xtra for next call. */
97 if (xtra[0] != 'z')
98 xtra[0]++;
99 else {
100 xtra[0] = 'a';
101 if (xtra[1] != 'z')
102 xtra[1]++;
103 else
104 xtra[1] = 'a';
105 }
106
107 /*
108 * check the target directory; if you have six X's and it
109 * doesn't exist this runs for a *very* long time.
110 */
111 for (start = trv + 1;; --trv) {
112 if (trv <= path)
113 break;
114 if (*trv == '/') {
115 *trv = '\0';
116 if (stat(path, &sbuf))
117 return (0);
118 if (!S_ISDIR(sbuf.st_mode)) {
119 errno = ENOTDIR;
120 return (0);
121 }
122 *trv = '/';
123 break;
124 }
125 }
126
127 for (;;) {
128 if ((fd=open(path, O_CREAT|O_EXCL|O_RDWR|O_BINARY, 0600)) >= 0)
129 return (fd);
130 if (errno != EEXIST)
131 return (0);
132
133 /* tricky little algorithm for backward compatibility */
134 for (trv = start;;) {
135 if (!*trv)
136 return (0);
137 if (*trv == 'z')
138 *trv++ = 'a';
139 else {
140 if (isdigit((unsigned char)*trv))
141 *trv = 'a';
142 else
143 ++*trv;
144 break;
145 }
146 }
147 }
148 /*NOTREACHED*/
149 #endif
150 }