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 #ifndef _WIN32
47 #include <unistd.h>
48 #endif
49
50 #ifndef O_BINARY
51 #define O_BINARY 0
52 #endif
53
54
55 int
_zip_mkstemp(char * path)56 _zip_mkstemp(char *path)
57 {
58 #ifdef _WIN32
59 int ret;
60 ret = _creat(_mktemp(path), _S_IREAD|_S_IWRITE);
61 if (ret == -1) {
62 return 0;
63 } else {
64 return ret;
65 }
66 #else
67 int fd;
68 char *start, *trv;
69 struct stat sbuf;
70 pid_t pid;
71
72 /* To guarantee multiple calls generate unique names even if
73 the file is not created. 676 different possibilities with 7
74 or more X's, 26 with 6 or less. */
75 static char xtra[2] = "aa";
76 int xcnt = 0;
77
78 pid = getpid();
79
80 /* Move to end of path and count trailing X's. */
81 for (trv = path; *trv; ++trv)
82 if (*trv == 'X')
83 xcnt++;
84 else
85 xcnt = 0;
86
87 /* Use at least one from xtra. Use 2 if more than 6 X's. */
88 if (*(trv - 1) == 'X')
89 *--trv = xtra[0];
90 if (xcnt > 6 && *(trv - 1) == 'X')
91 *--trv = xtra[1];
92
93 /* Set remaining X's to pid digits with 0's to the left. */
94 while (*--trv == 'X') {
95 *trv = (pid % 10) + '0';
96 pid /= 10;
97 }
98
99 /* update xtra for next call. */
100 if (xtra[0] != 'z')
101 xtra[0]++;
102 else {
103 xtra[0] = 'a';
104 if (xtra[1] != 'z')
105 xtra[1]++;
106 else
107 xtra[1] = 'a';
108 }
109
110 /*
111 * check the target directory; if you have six X's and it
112 * doesn't exist this runs for a *very* long time.
113 */
114 for (start = trv + 1;; --trv) {
115 if (trv <= path)
116 break;
117 if (*trv == '/') {
118 *trv = '\0';
119 if (stat(path, &sbuf))
120 return (0);
121 if (!S_ISDIR(sbuf.st_mode)) {
122 errno = ENOTDIR;
123 return (0);
124 }
125 *trv = '/';
126 break;
127 }
128 }
129
130 for (;;) {
131 if ((fd=open(path, O_CREAT|O_EXCL|O_RDWR|O_BINARY, 0600)) >= 0)
132 return (fd);
133 if (errno != EEXIST)
134 return (0);
135
136 /* tricky little algorithm for backward compatibility */
137 for (trv = start;;) {
138 if (!*trv)
139 return (0);
140 if (*trv == 'z')
141 *trv++ = 'a';
142 else {
143 if (isdigit((unsigned char)*trv))
144 *trv = 'a';
145 else
146 ++*trv;
147 break;
148 }
149 }
150 }
151 /*NOTREACHED*/
152 #endif
153 }
154
