Add apr_temp_dir_get(), a function to get the most suitable directory to place

temp files based on environment variables and other factors.

Obtained from: C Mike Pilato <cmpilato@collab.net>
Reviewed by: Thom May


git-svn-id: https://svn.apache.org/repos/asf/apr/apr/trunk@64591 13f79535-47bb-0310-9956-ffa450edef68

6 files changed, 193 insertions, 1 deletions

diff --git a/NWGNUmakefile b/NWGNUmakefile
index d70976ba6..3f1083a03 100644
--- a/NWGNUmakefile
+++ b/NWGNUmakefile
@@ -286,6 +286,7 @@ FILES_lib_objs = \
 	$(OBJDIR)/sockets.o \
 	$(OBJDIR)/sockopt.o \
 	$(OBJDIR)/start.o \
+	$(OBJDIR)/tempdir.o \
 	$(OBJDIR)/thread.o \
 	$(OBJDIR)/thread_cond.o \
 	$(OBJDIR)/thread_mutex.o \
diff --git a/apr.dsp b/apr.dsp
index 285694be8..b58c6f1b3 100644
--- a/apr.dsp
+++ b/apr.dsp
@@ -155,6 +155,10 @@ SOURCE=.\file_io\win32\readwrite.c
 
 SOURCE=.\file_io\win32\seek.c
 # End Source File
+# Begin Source File
+
+SOURCE=.\file_io\unix\tempdir.c
+# End Source File
 # End Group
 # Begin Group "locks"
 
diff --git a/file_io/unix/Makefile.in b/file_io/unix/Makefile.in
index 01473a801..fbc93b1c7 100644
--- a/file_io/unix/Makefile.in
+++ b/file_io/unix/Makefile.in
@@ -15,7 +15,8 @@ TARGETS = \
 	pipe.lo \
 	readwrite.lo \
 	seek.lo \
-	mktemp.lo
+	mktemp.lo \
+	tempdir.lo
 
 # bring in rules.mk for standard functionality
 @INCLUDE_RULES@
diff --git a/file_io/unix/tempdir.c b/file_io/unix/tempdir.c
new file mode 100644
index 000000000..b9bc80a8b
--- /dev/null
+++ b/file_io/unix/tempdir.c
@@ -0,0 +1,166 @@
+/* ====================================================================
+ * The Apache Software License, Version 1.1
+ *
+ * Copyright (c) 2000-2003 The Apache Software Foundation.  All rights
+ * reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ *
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in
+ *    the documentation and/or other materials provided with the
+ *    distribution.
+ *
+ * 3. The end-user documentation included with the redistribution,
+ *    if any, must include the following acknowledgment:
+ *       "This product includes software developed by the
+ *        Apache Software Foundation (http://www.apache.org/)."
+ *    Alternately, this acknowledgment may appear in the software itself,
+ *    if and wherever such third-party acknowledgments normally appear.
+ *
+ * 4. The names "Apache" and "Apache Software Foundation" must
+ *    not be used to endorse or promote products derived from this
+ *    software without prior written permission. For written
+ *    permission, please contact apache@apache.org.
+ *
+ * 5. Products derived from this software may not be called "Apache",
+ *    nor may "Apache" appear in their name, without prior written
+ *    permission of the Apache Software Foundation.
+ *
+ * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED
+ * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
+ * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+ * DISCLAIMED.  IN NO EVENT SHALL THE APACHE SOFTWARE FOUNDATION OR
+ * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
+ * USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
+ * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
+ * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
+ * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ * ====================================================================
+ *
+ * This software consists of voluntary contributions made by many
+ * individuals on behalf of the Apache Software Foundation.  For more
+ * information on the Apache Software Foundation, please see
+ * <http://www.apache.org/>.
+ */
+#include "apr_private.h"
+#include "apr_file_io.h"
+#include "apr_strings.h"
+#include "apr_env.h"
+
+/*
+ * FIXME
+ * Currently, this variable is a bit of misnomer.
+ * The intention is to have this in APR's global pool so that we don't have 
+ * to go through this every time.
+ */
+static char global_temp_dir[APR_PATH_MAX+1] = { 0 };
+
+/* 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;
+    const char *path = apr_pstrcat(p, temp_dir, "/apr-tmp", NULL);
+
+    if (apr_file_mktemp(&dummy_file, (char *)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[] = { "TMP", "TEMP", "TMPDIR" };
+    char *cwd;
+    int i;
+
+    /* Our goal is to find a temporary directory suitable for writing
+       into.  We'll only pay the price once if we're successful -- we
+       cache our successful find.  Here's the order in which we'll try
+       various paths:
+
+          $TMP
+          $TEMP
+          $TMPDIR
+          "C:\TEMP"     (windows 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)) {
+                memcpy(global_temp_dir, value, len + 1);
+                goto end;
+            }
+        }
+    }
+
+#ifdef WIN32
+    /* Next, on Win32, try the C:\TEMP directory. */
+    if (test_tempdir("C:\\TEMP", p)) {
+        memcpy(global_temp_dir, "C:\\TEMP", 7 + 1);
+        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)) {
+            memcpy(global_temp_dir, try_dirs[i], strlen(try_dirs[i]) + 1);
+            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)) {
+        memcpy(global_temp_dir, P_tmpdir, strlen(P_tmpdir) +1);
+        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)) {
+            memcpy(global_temp_dir, cwd, strlen(cwd) + 1);
+            goto end;
+        }
+    }
+
+end:
+    if (global_temp_dir[0]) {
+        *temp_dir = apr_pstrdup(p, global_temp_dir);
+        return APR_SUCCESS;
+    }
+    return APR_EGENERAL;
+}
diff --git a/include/apr_file_io.h b/include/apr_file_io.h
index 68ad4b1c4..dbc8d422d 100644
--- a/include/apr_file_io.h
+++ b/include/apr_file_io.h
@@ -764,6 +764,22 @@ APR_DECLARE(void) apr_file_unset_inherit(apr_file_t *file);
 APR_DECLARE(apr_status_t) apr_file_mktemp(apr_file_t **fp, char *templ,
                                           apr_int32_t flags, apr_pool_t *p);
 
+
+/**
+ * Find an existing directory suitable as a temporary storage location.
+ * @param temp_dir The temp directory.
+ * @param p The pool to use for any necessary allocations.
+ * @remark   
+ * This function uses an algorithm to search for a directory that an
+ * an application can use for temporary storage.  Once such a
+ * directory is found, that location is cached by the library.  Thus,
+ * callers only pay the cost of this algorithm once if that one time
+ * is successful.
+ *
+ */
+APR_DECLARE(apr_status_t) apr_temp_dir_get(const char **temp_dir, 
+                                           apr_pool_t *p);
+
 /** @} */
 
 #ifdef __cplusplus
diff --git a/libapr.dsp b/libapr.dsp
index 95191f378..070f5ed5f 100644
--- a/libapr.dsp
+++ b/libapr.dsp
@@ -161,6 +161,10 @@ SOURCE=.\file_io\win32\readwrite.c
 
 SOURCE=.\file_io\win32\seek.c
 # End Source File
+# Begin Source File
+
+SOURCE=.\file_io\unix\tempdir.c
+# End Source File
 # End Group
 # Begin Group "locks"