/* Licensed to the Apache Software Foundation (ASF) under one or more

 * contributor license agreements.  See the NOTICE file distributed with

 * this work for additional information regarding copyright ownership.

 * The ASF licenses this file to You under the Apache License, Version 2.0

 * (the "License"); you may not use this file except in compliance with

 * the License.  You may obtain a copy of the License at

 *

 *     http://www.apache.org/licenses/LICENSE-2.0

 *

 * Unless required by applicable law or agreed to in writing, software

 * distributed under the License is distributed on an "AS IS" BASIS,

 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.

 * See the License for the specific language governing permissions and

 * limitations under the License.

 */

#include "apr_private.h"

#include "apr_file_io.h"

#include "apr_strings.h"

#include "apr_env.h"

/* Try to open a temporary file in the temporary dir, write to it,

   and then close it. */

static int test_tempdir(const char *temp_dir, apr_pool_t *p)

{

    apr_file_t *dummy_file;

    char *path = apr_pstrcat(p, temp_dir, "/apr-tmp.XXXXXX", NULL);

    if (apr_file_mktemp(&dummy_file, path, 0, p) == APR_SUCCESS) {

        if (apr_file_putc('!', dummy_file) == APR_SUCCESS) {

            if (apr_file_close(dummy_file) == APR_SUCCESS) {

                return 1;

            }

        }

    }

    return 0;

}

APR_DECLARE(apr_status_t) apr_temp_dir_get(const char **temp_dir,

                                           apr_pool_t *p)

{

    apr_status_t apr_err;

    const char *try_dirs[] = { "/tmp", "/usr/tmp", "/var/tmp" };

    const char *try_envs[] = { "TMPDIR", "TMP", "TEMP"};

    const char *dir;

    char *cwd;

    int i;

    /* Our goal is to find a temporary directory suitable for writing

       into.

       Here's the order in which we'll try various paths:

          $TMPDIR

          $TMP

          $TEMP

          "C:\TEMP"     (windows only)

          "SYS:\TMP"    (netware only)

          "/tmp"

          "/var/tmp"

          "/usr/tmp"

          P_tmpdir      (POSIX define)

          `pwd`

       NOTE: This algorithm is basically the same one used by Python

       2.2's tempfile.py module.  */

    /* Try the environment first. */

    for (i = 0; i < (sizeof(try_envs) / sizeof(const char *)); i++) {

        char *value;

        apr_err = apr_env_get(&value, try_envs[i], p);

        if ((apr_err == APR_SUCCESS) && value) {

            apr_size_t len = strlen(value);

            if (len && (len < APR_PATH_MAX) && test_tempdir(value, p)) {

                dir = value;

                goto end;

            }

        }

    }

#ifdef WIN32

    /* Next, on Win32, try the C:\TEMP directory. */

    if (test_tempdir("C:\\TEMP", p)) {

        dir = "C:\\TEMP";

        goto end;

    }

#endif

#ifdef NETWARE

    /* Next, on NetWare, try the SYS:/TMP directory. */

    if (test_tempdir("SYS:/TMP", p)) {

        dir = "SYS:/TMP";

        goto end;

    }

#endif

    /* Next, try a set of hard-coded paths. */

    for (i = 0; i < (sizeof(try_dirs) / sizeof(const char *)); i++) {

        if (test_tempdir(try_dirs[i], p)) {

            dir = try_dirs[i];

            goto end;

        }

    }

#ifdef P_tmpdir

    /*

     * If we have it, use the POSIX definition of where

     * the tmpdir should be

     */

    if (test_tempdir(P_tmpdir, p)) {

        dir = P_tmpdir;

        goto end;

    }

#endif

    /* Finally, try the current working directory. */

    if (APR_SUCCESS == apr_filepath_get(&cwd, APR_FILEPATH_NATIVE, p)) {

        if (test_tempdir(cwd, p)) {

            dir = cwd;

      goto end;

        }

    }

    /* We didn't find a suitable temp dir anywhere */

    return APR_EGENERAL;

end:

    *temp_dir = apr_pstrdup(p, dir);

    return APR_SUCCESS;

}