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// -*- c++ -*-
// Distributed under the BSD 2-Clause License.
// See accompanying file LICENSE for details.
#include "execute.h"
#include <unistd.h>
#include <cstring>
#include <sys/types.h>
#include <sys/wait.h>
#include <spawn.h>
#include <iostream>
/*
https://blog.famzah.net/2009/11/20/a-much-faster-popen-and-system-implementation-for-linux/
https://github.com/famzah/popen-noshell/commit/1f9eaf4eeef348d1efe0f3c7fe8ab670653cfbb1
https://blog.famzah.net/2018/12/19/posix_spawn-performance-benchmarks-and-usage-examples/
https://stackoverflow.com/questions/4259629/what-is-the-difference-between-fork-and-vfork/5207945#5207945
*/
namespace
{
int parent_waitpid(pid_t pid)
{
int status;
if(waitpid(pid, &status, 0) != pid)
{
return 1;
}
return WEXITSTATUS(status);
}
} // namespace ::
int execute(const std::string& command,
const std::vector<std::string>& args,
bool verbose)
{
std::vector<const char*> argv;
argv.push_back(command.data());
for(const auto& arg : args)
{
argv.push_back(arg.data());
}
argv.push_back(nullptr);
if(verbose)
{
std::string cmd;
for(const auto& arg : argv)
{
if(arg == nullptr)
{
break;
}
if(!cmd.empty())
{
cmd += " ";
}
cmd += arg;
}
std::cout << cmd << "\n";
}
#if 1
auto pid = vfork();
if(pid == 0)
{
execv(command.data(), (char**)argv.data());
std::cout << "Could not execute " << command << ": " <<
strerror(errno) << "\n";
_exit(1); // execv only returns if an error occurred
}
auto ret = parent_waitpid(pid);
#elif 0
pid_t pid;
if(posix_spawn(&pid, command.data(), nullptr, nullptr,
(char**)argv.data(), nullptr))
{
return 1;
}
auto ret = parent_waitpid(pid);
#else
auto ret = system(cmd.data());
#endif
return ret;
}
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