• 1. 关键词
• 2. sysutil.h
• 3. sysutil.cpp
  • 3.1. system_util_unix.cpp
  • 3.2. system_util_win.cpp
• 4. 测试代码
• 5. 运行结果
• 6. 源码地址

1. 关键词

关键词：

C++ 系统调用 system popen 跨平台

应用场景：

希望直接调用操作系统的某些命令，并获取命令的返回值。

2. sysutil.h

#pragma once

#include <cstdint>

#include <string>

namespace cutl

{

/**

* @brief Execute a system command.

*

* @param cmd the command to be executed.

* @return true if the command is executed successfully, false otherwise.

*/

bool system(const std::string &cmd);

/**

* @brief Execute a system command and get the output.

*

* @param cmd the command to be executed.

* @param result the output of the command.

* @return true if the command is executed successfully, false otherwise.

*/

bool callcmd(const std::string &cmd, std::string &result);

} // namespace cutl

不需要返回值时，可以直接使用system， 需要获取返回值时，可以调用callcmd。

3. sysutil.cpp

#include <map>

#include <iostream>

#include <strutil.h>

#include <cstdlib>

#include "sysutil.h"

#include "inner/logger.h"

#include "inner/system_util.h"

#include "inner/filesystem.h"

namespace cutl

{

bool system(const std::string &cmd)

{

return call_system(cmd);

}

bool callcmd(const std::string &cmd, std::string &result)

{

// 读取命令执行结果的最大Buffer长度

constexpr int MAX_CMD_BUF_LEN = 1024;

FILE *fp = pipline_open(cmd);

if (fp == NULL)

{

CUTL_ERROR("pipline_open error for cmd:" + cmd);

return false;

}

// 读取命令执行结果

char buffer[MAX_CMD_BUF_LEN] = {0};

char *res = fgets(buffer, sizeof(buffer), fp);

if (res == NULL)

{

CUTL_ERROR("read result error for cmd:" + cmd);

if (pipline_close(fp) != 0)

{

CUTL_ERROR("pipline_close error for cmd:" + cmd);

}

return false;

}

if (pipline_close(fp) != 0)

{

CUTL_ERROR("pipline_close error for cmd:" + cmd);

}

result = strip(std::string(buffer));

return true;

}

} // namespace cutl

3.1. system_util_unix.cpp

#if defined(_WIN32) || defined(__WIN32__)

// do nothing

#else

#include "system_util.h"

#include "inner/logger.h"

namespace cutl

{

bool call_system(const std::string &cmd)

{

if (cmd.empty())

{

CUTL_ERROR("cmd is empty!");

return false;

}

pid_t status;

status = std::system(cmd.c_str());

if (-1 == status)

{

CUTL_ERROR("system error!");

return false;

}

if (!WIFEXITED(status))

{

CUTL_ERROR("exit status:" + std::to_string(WEXITSTATUS(status)));

return false;

}

if (0 != WEXITSTATUS(status))

{

CUTL_ERROR("run shell script fail, script exit code:" + std::to_string(WEXITSTATUS(status)));

return false;

}

return true;

}

FILE *pipline_open(const std::string &cmd)

{

return popen(cmd.c_str(), "r");

}

int pipline_close(FILE *stream)

{

return pclose(stream);

}

} // namespace cutl

#endif // defined(_WIN32) || defined(__WIN32__)

3.2. system_util_win.cpp

#if defined(_WIN32) || defined(__WIN32__)

#include <cstdlib>

#include "system_util.h"

#include "inner/logger.h"

namespace cutl

{

// https://learn.microsoft.com/zh-cn/cpp/c-runtime-library/reference/system-wsystem?view=msvc-170

bool call_system(const std::string &cmd)

{

if (cmd.empty())

{

CUTL_ERROR("cmd is empty!");

return false;

}

int ret = system(cmd.c_str());

if (ret != 0)

{

CUTL_ERROR(std::string("system failure, error") + strerror(errno));

return false;

}

return true;

}

// https://learn.microsoft.com/zh-cn/cpp/c-runtime-library/reference/popen-wpopen?view=msvc-170

FILE *pipline_open(const std::string &cmd)

{

return _popen(cmd.c_str(), "r");

}

// https://learn.microsoft.com/zh-cn/cpp/c-runtime-library/reference/pclose?view=msvc-170

int pipline_close(FILE *stream)

{

return _pclose(stream);

}

} // namespace cutl

#endif // defined(_WIN32) || defined(__WIN32__)

4. 测试代码

#include "common.hpp"

#include "sysutil.h"

void TestSystemCall()

{

PrintSubTitle("TestSystemCall");

bool ret = cutl::system("echo hello");

std::cout << "system call 'echo hello', return: " << ret << std::endl;

auto cmd = "cmake --version";

std::string result_text;

ret = cutl::callcmd(cmd, result_text);

std::cout << "callcmd " << cmd << ", return: " << ret << std::endl;

std::cout << "callcmd " << cmd << ", result text: " << result_text << std::endl;

}

5. 运行结果

-------------------------------------------TestSystemCall-------------------------------------------

hello

system call 'echo hello', return: 1

callcmd cmake --version, return: 1

callcmd cmake --version, result text: cmake version 3.28.3

6. 源码地址

更多详细代码，请查看本人写的C++ 通用工具库: common_util, 本项目已开源，代码简洁，且有详细的文档和Demo。

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