libandroidfw: introduce ExecuteBinary (POSIX only)
Introduce a wrapper around fork and exec.
Test: make libandroidfw_tests
Change-Id: Iff0de5319bb6bb101a3fbef6413dfb4e77198f11
diff --git a/libs/androidfw/PosixUtils.cpp b/libs/androidfw/PosixUtils.cpp
new file mode 100644
index 0000000..df0dd7c
--- /dev/null
+++ b/libs/androidfw/PosixUtils.cpp
@@ -0,0 +1,112 @@
+/*
+ * Copyright (C) 2018 The Android Open Source Project
+ *
+ * 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
+ *
+ * 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.
+ */
+
+#ifdef _WIN32
+// nothing to see here
+#else
+#include <memory>
+#include <string>
+#include <vector>
+
+#include <sys/types.h>
+#include <sys/wait.h>
+#include <unistd.h>
+
+#include "android-base/logging.h"
+
+#include "androidfw/PosixUtils.h"
+
+namespace {
+
+std::unique_ptr<std::string> ReadFile(int fd) {
+ std::unique_ptr<std::string> str(new std::string());
+ char buf[1024];
+ ssize_t r;
+ while ((r = read(fd, buf, sizeof(buf))) > 0) {
+ str->append(buf, r);
+ }
+ if (r != 0) {
+ return nullptr;
+ }
+ return str;
+}
+
+}
+
+namespace android {
+namespace util {
+
+std::unique_ptr<ProcResult> ExecuteBinary(const std::vector<std::string>& argv) {
+ int stdout[2]; // stdout[0] read, stdout[1] write
+ if (pipe(stdout) != 0) {
+ PLOG(ERROR) << "pipe";
+ return nullptr;
+ }
+
+ int stderr[2]; // stdout[0] read, stdout[1] write
+ if (pipe(stderr) != 0) {
+ PLOG(ERROR) << "pipe";
+ close(stdout[0]);
+ close(stdout[1]);
+ return nullptr;
+ }
+
+ char const** argv0 = (char const**)malloc(sizeof(char*) * (argv.size() + 1));
+ for (size_t i = 0; i < argv.size(); i++) {
+ argv0[i] = argv[i].c_str();
+ }
+ argv0[argv.size()] = nullptr;
+ switch (fork()) {
+ case -1: // error
+ free(argv0);
+ PLOG(ERROR) << "fork";
+ return nullptr;
+ case 0: // child
+ close(stdout[0]);
+ if (dup2(stdout[1], STDOUT_FILENO) == -1) {
+ abort();
+ }
+ close(stderr[0]);
+ if (dup2(stderr[1], STDERR_FILENO) == -1) {
+ abort();
+ }
+ execvp(argv0[0], const_cast<char* const*>(argv0));
+ PLOG(ERROR) << "execv";
+ abort();
+ default: // parent
+ free(argv0);
+ close(stdout[1]);
+ close(stderr[1]);
+ int status;
+ wait(&status);
+ if (!WIFEXITED(status)) {
+ return nullptr;
+ }
+ std::unique_ptr<ProcResult> result(new ProcResult());
+ result->status = status;
+ const auto out = ReadFile(stdout[0]);
+ result->stdout = out ? *out : "";
+ close(stdout[0]);
+ const auto err = ReadFile(stderr[0]);
+ result->stderr = err ? *err : "";
+ close(stderr[0]);
+ return result;
+ }
+}
+
+} // namespace util
+} // namespace android
+#endif