Linux: Add support for loading environment variables at plugin start-up from ...

plugin/linux/envvars.cc

+/*
+ * Copyright 2009, Google Inc.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are
+ * met:
+ *
+ *     * Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ *     * 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.
+ *     * Neither the name of Google Inc. nor the names of its
+ * contributors may be used to endorse or promote products derived from
+ * this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS 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 COPYRIGHT
+ * OWNER OR 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.
+ */
+
+#include <stdio.h>
+#include <string.h>
+
+#include "plugin/linux/envvars.h"
+
+#include "base/logging.h"
+
+namespace o3d {
+
+static const unsigned int kMaxEnvVarLength = 1024;
+
+void LoadEnvironmentVariablesFile(const char *path) {
+  FILE *env_vars_file = fopen(path, "r");
+  // It is not an error if the file is missing. We treat it the same as if it
+  // were empty.
+  if (env_vars_file) {
+    char buffer[kMaxEnvVarLength];
+    while (!feof(env_vars_file) ) {
+      if (fgets(buffer, sizeof(buffer), env_vars_file)) {
+        char *equals = strchr(buffer, '=');
+        if (!equals) {
+          LOG(ERROR) << "Malformed environment variables file";
+          continue;
+        }
+        char *value = equals + 1;
+        *equals = '\0';
+        int length = strlen(value);
+        if (value[length - 1] == '\n') {
+          value[length - 1] = '\0';
+        }
+        if (setenv(buffer, value, 1) != 0) {
+          LOG(ERROR) << "Couldn't add " << buffer << "=" << value
+              << " to environment";
+        } else {
+          // Custom environment variables could be relevant for debugging
+          // problem reports, so log this too.
+          LOG(INFO) << "Defined " << buffer << "=" << value;
+        }
+      } else if (ferror(env_vars_file)) {
+        PLOG(ERROR) << "Error reading from environment variables file";
+        break;
+      } else {
+        break;
+      }
+    }
+    if (fclose(env_vars_file) != 0) {
+      PLOG(ERROR) << "Unable to close environment variables file";
+    }
+  }
+}
+
+}  // namespace o3d