summaryrefslogtreecommitdiff
path: root/absl/base/internal/scoped_set_env.cc
diff options
context:
space:
mode:
Diffstat (limited to 'absl/base/internal/scoped_set_env.cc')
-rw-r--r--absl/base/internal/scoped_set_env.cc79
1 files changed, 79 insertions, 0 deletions
diff --git a/absl/base/internal/scoped_set_env.cc b/absl/base/internal/scoped_set_env.cc
new file mode 100644
index 00000000..9b164124
--- /dev/null
+++ b/absl/base/internal/scoped_set_env.cc
@@ -0,0 +1,79 @@
+// Copyright 2019 The Abseil Authors.
+//
+// Licensed 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
+//
+// https://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 "absl/base/internal/scoped_set_env.h"
+
+#ifdef _WIN32
+#include <windows.h>
+#endif
+
+#include <cstdlib>
+
+#include "absl/base/internal/raw_logging.h"
+
+namespace absl {
+namespace base_internal {
+
+namespace {
+
+#ifdef _WIN32
+const int kMaxEnvVarValueSize = 1024;
+#endif
+
+void SetEnvVar(const char* name, const char* value) {
+#ifdef _WIN32
+ SetEnvironmentVariable(name, value);
+#else
+ if (value == nullptr) {
+ ::unsetenv(name);
+ } else {
+ ::setenv(name, value, 1);
+ }
+#endif
+}
+
+} // namespace
+
+ScopedSetEnv::ScopedSetEnv(const char* var_name, const char* new_value)
+ : var_name_(var_name), was_unset_(false) {
+#ifdef _WIN32
+ char buf[kMaxEnvVarValueSize];
+ auto get_res = GetEnvironmentVariable(var_name_.c_str(), buf, sizeof(buf));
+ ABSL_INTERNAL_CHECK(get_res < sizeof(buf), "value exceeds buffer size");
+
+ if (get_res == 0) {
+ was_unset_ = (GetLastError() == ERROR_ENVVAR_NOT_FOUND);
+ } else {
+ old_value_.assign(buf, get_res);
+ }
+
+ SetEnvironmentVariable(var_name_.c_str(), new_value);
+#else
+ const char* val = ::getenv(var_name_.c_str());
+ if (val == nullptr) {
+ was_unset_ = true;
+ } else {
+ old_value_ = val;
+ }
+#endif
+
+ SetEnvVar(var_name_.c_str(), new_value);
+}
+
+ScopedSetEnv::~ScopedSetEnv() {
+ SetEnvVar(var_name_.c_str(), was_unset_ ? nullptr : old_value_.c_str());
+}
+
+} // namespace base_internal
+} // namespace absl