1 /*
2 * Copyright (C) 2015 The Android Open Source Project
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
7 *
8 * http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 */
16
17 #include "android-base/test_utils.h"
18
19 #include <fcntl.h>
20 #include <stdio.h>
21 #include <stdlib.h>
22 #include <sys/stat.h>
23 #include <unistd.h>
24
25 #include <string>
26
27 #include <android-base/file.h>
28 #include <android-base/logging.h>
29
CapturedStdFd(int std_fd)30 CapturedStdFd::CapturedStdFd(int std_fd) : std_fd_(std_fd), old_fd_(-1) {
31 Start();
32 }
33
~CapturedStdFd()34 CapturedStdFd::~CapturedStdFd() {
35 if (old_fd_ != -1) {
36 Stop();
37 }
38 }
39
fd() const40 int CapturedStdFd::fd() const {
41 return temp_file_.fd;
42 }
43
str()44 std::string CapturedStdFd::str() {
45 std::string result;
46 CHECK_EQ(0, TEMP_FAILURE_RETRY(lseek(fd(), 0, SEEK_SET)));
47 android::base::ReadFdToString(fd(), &result);
48 return result;
49 }
50
Reset()51 void CapturedStdFd::Reset() {
52 // Do not reset while capturing.
53 CHECK_EQ(-1, old_fd_);
54 CHECK_EQ(0, TEMP_FAILURE_RETRY(lseek(fd(), 0, SEEK_SET)));
55 CHECK_EQ(0, ftruncate(fd(), 0));
56 }
57
Start()58 void CapturedStdFd::Start() {
59 #if defined(_WIN32)
60 // On Windows, stderr is often buffered, so make sure it is unbuffered so
61 // that we can immediately read back what was written to stderr.
62 if (std_fd_ == STDERR_FILENO) CHECK_EQ(0, setvbuf(stderr, nullptr, _IONBF, 0));
63 #endif
64 old_fd_ = dup(std_fd_);
65 CHECK_NE(-1, old_fd_);
66 CHECK_NE(-1, dup2(fd(), std_fd_));
67 }
68
Stop()69 void CapturedStdFd::Stop() {
70 CHECK_NE(-1, old_fd_);
71 CHECK_NE(-1, dup2(old_fd_, std_fd_));
72 close(old_fd_);
73 old_fd_ = -1;
74 // Note: cannot restore prior setvbuf() setting.
75 }
76