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
53int
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}
152