src/kudu/util/subprocess-test.cc

// Copyright 2014 Cloudera, Inc.
//
// 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.

#include <vector>
#include <string>

#include <gtest/gtest.h>
#include "kudu/util/subprocess.h"
#include "kudu/util/test_util.h"

using std::string;
using std::vector;

namespace kudu {

class SubprocessTest : public KuduTest {};

TEST_F(SubprocessTest, TestSimplePipe) {
  vector<string> argv;
  argv.push_back("tr");
  argv.push_back("a-z");
  argv.push_back("A-Z");
  Subprocess p("/usr/bin/tr", argv);
  p.ShareParentStdout(false);
  ASSERT_OK(p.Start());

  FILE* out = fdopen(p.ReleaseChildStdinFd(), "w");
  PCHECK(out);
  FILE* in = fdopen(p.from_child_stdout_fd(), "r");
  PCHECK(in);

  fprintf(out, "hello world\n");
  // We have to close 'out' or else tr won't write any output, since
  // it enters a buffered mode if it detects that its input is a FIFO.
  fclose(out);

  char buf[1024];
  ASSERT_EQ(buf, fgets(buf, sizeof(buf), in));
  ASSERT_STREQ("HELLO WORLD\n", &buf[0]);

  int wait_status = 0;
  ASSERT_OK(p.Wait(&wait_status));
  ASSERT_TRUE(WIFEXITED(wait_status));
  ASSERT_EQ(0, WEXITSTATUS(wait_status));
}

TEST_F(SubprocessTest, TestErrPipe) {
  vector<string> argv;
  argv.push_back("tee");
  argv.push_back("/dev/stderr");
  Subprocess p("/usr/bin/tee", argv);
  p.ShareParentStderr(false);
  ASSERT_OK(p.Start());

  FILE* out = fdopen(p.ReleaseChildStdinFd(), "w");
  PCHECK(out);

  fprintf(out, "Hello, World\n");
  fclose(out); // same reasoning as above, flush to prevent tee buffering

  FILE* in = fdopen(p.from_child_stderr_fd(), "r");
  PCHECK(in);

  char buf[1024];
  ASSERT_EQ(buf, fgets(buf, sizeof(buf), in));
  ASSERT_STREQ("Hello, World\n", &buf[0]);

  int wait_status = 0;
  ASSERT_OK(p.Wait(&wait_status));
  ASSERT_TRUE(WIFEXITED(wait_status));
  ASSERT_EQ(0, WEXITSTATUS(wait_status));
}

TEST_F(SubprocessTest, TestKill) {
  vector<string> argv;
  argv.push_back("cat");
  Subprocess p("/bin/cat", argv);
  ASSERT_OK(p.Start());

  ASSERT_OK(p.Kill(SIGKILL));

  int wait_status = 0;
  ASSERT_OK(p.Wait(&wait_status));
  ASSERT_EQ(SIGKILL, WTERMSIG(wait_status));

  // Test that calling Wait() a second time returns the same
  // cached value instead of trying to wait on some other process
  // that was assigned the same pid.
  wait_status = 0;
  ASSERT_OK(p.Wait(&wait_status));
  ASSERT_EQ(SIGKILL, WTERMSIG(wait_status));
}

} // namespace kudu