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
53 int
54 _zip_mkstemp(char *path)
55 {
56 #ifdef _WIN32
57 int ret;
58 ret = _creat(_mktemp(path), _S_IREAD|_S_IWRITE);
59 if (ret == -1) {
60 return 0;
61 } else {
62 return ret;
63 }
64 #else
65 int fd;
66 char *start, *trv;
67 struct stat sbuf;
68 pid_t pid;
69
70 /* To guarantee multiple calls generate unique names even if
71 the file is not created. 676 different possibilities with 7
72 or more X's, 26 with 6 or less. */
73 static char xtra[2] = "aa";
74 int xcnt = 0;
75
76 pid = getpid();
77
78 /* Move to end of path and count trailing X's. */
79 for (trv = path; *trv; ++trv)
80 if (*trv == 'X')
81 xcnt++;
82 else
83 xcnt = 0;
84
85 /* Use at least one from xtra. Use 2 if more than 6 X's. */
86 if (*(trv - 1) == 'X')
87 *--trv = xtra[0];
88 if (xcnt > 6 && *(trv - 1) == 'X')
89 *--trv = xtra[1];
90
91 /* Set remaining X's to pid digits with 0's to the left. */
92 while (*--trv == 'X') {
93 *trv = (pid % 10) + '0';
94 pid /= 10;
95 }
96
97 /* update xtra for next call. */
98 if (xtra[0] != 'z')
99 xtra[0]++;
100 else {
101 xtra[0] = 'a';
102 if (xtra[1] != 'z')
103 xtra[1]++;
104 else
105 xtra[1] = 'a';
106 }
107
108 /*
109 * check the target directory; if you have six X's and it
110 * doesn't exist this runs for a *very* long time.
111 */
112 for (start = trv + 1;; --trv) {
113 if (trv <= path)
114 break;
115 if (*trv == '/') {
116 *trv = '\0';
117 if (stat(path, &sbuf))
118 return (0);
119 if (!S_ISDIR(sbuf.st_mode)) {
120 errno = ENOTDIR;
121 return (0);
122 }
123 *trv = '/';
124 break;
125 }
126 }
127
128 for (;;) {
129 if ((fd=open(path, O_CREAT|O_EXCL|O_RDWR|O_BINARY, 0600)) >= 0)
130 return (fd);
131 if (errno != EEXIST)
132 return (0);
133
134 /* tricky little algorithm for backward compatibility */
135 for (trv = start;;) {
136 if (!*trv)
137 return (0);
138 if (*trv == 'z')
139 *trv++ = 'a';
140 else {
141 if (isdigit((unsigned char)*trv))
142 *trv = 'a';
143 else
144 ++*trv;
145 break;
146 }
147 }
148 }
149 /*NOTREACHED*/
150 #endif
151 }