1/* Licensed to the Apache Software Foundation (ASF) under one or more
2 * contributor license agreements.  See the NOTICE file distributed with
3 * this work for additional information regarding copyright ownership.
4 * The ASF licenses this file to You under the Apache License, Version 2.0
5 * (the "License"); you may not use this file except in compliance with
6 * the License.  You may obtain a copy of the License at
7 *
8 *     http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 */
16#include "apr_private.h"
17#include "apr_file_io.h"
18#include "apr_strings.h"
19#include "apr_env.h"
20
21
22/* Try to open a temporary file in the temporary dir, write to it,
23   and then close it. */
24static int test_tempdir(const char *temp_dir, apr_pool_t *p)
25{
26    apr_file_t *dummy_file;
27    char *path = apr_pstrcat(p, temp_dir, "/apr-tmp.XXXXXX", NULL);
28
29    if (apr_file_mktemp(&dummy_file, path, 0, p) == APR_SUCCESS) {
30        if (apr_file_putc('!', dummy_file) == APR_SUCCESS) {
31            if (apr_file_close(dummy_file) == APR_SUCCESS) {
32                return 1;
33            }
34        }
35    }
36    return 0;
37}
38
39
40APR_DECLARE(apr_status_t) apr_temp_dir_get(const char **temp_dir,
41                                           apr_pool_t *p)
42{
43    apr_status_t apr_err;
44    const char *try_dirs[] = { "/tmp", "/usr/tmp", "/var/tmp" };
45    const char *try_envs[] = { "TMPDIR", "TMP", "TEMP"};
46    const char *dir;
47    char *cwd;
48    int i;
49
50    /* Our goal is to find a temporary directory suitable for writing
51       into.
52       Here's the order in which we'll try various paths:
53
54          $TMPDIR
55          $TMP
56          $TEMP
57          "C:\TEMP"     (windows only)
58          "SYS:\TMP"    (netware only)
59          "/tmp"
60          "/var/tmp"
61          "/usr/tmp"
62          P_tmpdir      (POSIX define)
63          `pwd`
64
65       NOTE: This algorithm is basically the same one used by Python
66       2.2's tempfile.py module.  */
67
68    /* Try the environment first. */
69    for (i = 0; i < (sizeof(try_envs) / sizeof(const char *)); i++) {
70        char *value;
71        apr_err = apr_env_get(&value, try_envs[i], p);
72        if ((apr_err == APR_SUCCESS) && value) {
73            apr_size_t len = strlen(value);
74            if (len && (len < APR_PATH_MAX) && test_tempdir(value, p)) {
75                dir = value;
76                goto end;
77            }
78        }
79    }
80
81#ifdef WIN32
82    /* Next, on Win32, try the C:\TEMP directory. */
83    if (test_tempdir("C:\\TEMP", p)) {
84        dir = "C:\\TEMP";
85        goto end;
86    }
87#endif
88#ifdef NETWARE
89    /* Next, on NetWare, try the SYS:/TMP directory. */
90    if (test_tempdir("SYS:/TMP", p)) {
91        dir = "SYS:/TMP";
92        goto end;
93    }
94#endif
95
96    /* Next, try a set of hard-coded paths. */
97    for (i = 0; i < (sizeof(try_dirs) / sizeof(const char *)); i++) {
98        if (test_tempdir(try_dirs[i], p)) {
99            dir = try_dirs[i];
100            goto end;
101        }
102    }
103
104#ifdef P_tmpdir
105    /*
106     * If we have it, use the POSIX definition of where
107     * the tmpdir should be
108     */
109    if (test_tempdir(P_tmpdir, p)) {
110        dir = P_tmpdir;
111        goto end;
112    }
113#endif
114
115    /* Finally, try the current working directory. */
116    if (APR_SUCCESS == apr_filepath_get(&cwd, APR_FILEPATH_NATIVE, p)) {
117        if (test_tempdir(cwd, p)) {
118            dir = cwd;
119	    goto end;
120        }
121    }
122
123    /* We didn't find a suitable temp dir anywhere */
124    return APR_EGENERAL;
125
126end:
127    *temp_dir = apr_pstrdup(p, dir);
128    return APR_SUCCESS;
129}
130