ladybird/Userland/Libraries/LibCore/Command.cpp
2021-08-01 08:10:16 +02:00

104 lines
2.8 KiB
C++

/*
* Copyright (c) 2020, Itamar S. <itamar8910@gmail.com>
*
* SPDX-License-Identifier: BSD-2-Clause
*/
#include "Command.h"
#include <AK/Format.h>
#include <AK/ScopeGuard.h>
#include <LibCore/File.h>
#include <fcntl.h>
#include <stdio.h>
#include <sys/wait.h>
#include <unistd.h>
namespace Core {
// Only supported in serenity mode because we use `posix_spawn_file_actions_addchdir`
#ifdef __serenity__
String command(const String& command_string, Optional<LexicalPath> chdir)
{
auto parts = command_string.split(' ');
if (parts.is_empty())
return {};
auto program = parts[0];
parts.remove(0);
return command(program, parts, chdir);
}
String command(const String& program, const Vector<String>& arguments, Optional<LexicalPath> chdir)
{
int stdout_pipe[2] = {};
int stderr_pipe[2] = {};
if (pipe2(stdout_pipe, O_CLOEXEC)) {
perror("pipe2");
VERIFY_NOT_REACHED();
}
if (pipe2(stderr_pipe, O_CLOEXEC)) {
perror("pipe2");
VERIFY_NOT_REACHED();
}
auto close_pipes = ScopeGuard([stderr_pipe, stdout_pipe] {
// The write-ends of these pipes are closed manually
close(stdout_pipe[0]);
close(stderr_pipe[0]);
});
Vector<const char*> parts = { program.characters() };
for (const auto& part : arguments) {
parts.append(part.characters());
}
parts.append(nullptr);
const char** argv = parts.data();
posix_spawn_file_actions_t action;
posix_spawn_file_actions_init(&action);
if (chdir.has_value()) {
posix_spawn_file_actions_addchdir(&action, chdir.value().string().characters());
}
posix_spawn_file_actions_adddup2(&action, stdout_pipe[1], STDOUT_FILENO);
posix_spawn_file_actions_adddup2(&action, stderr_pipe[1], STDERR_FILENO);
pid_t pid;
if ((errno = posix_spawnp(&pid, program.characters(), &action, nullptr, const_cast<char**>(argv), environ))) {
perror("posix_spawn");
VERIFY_NOT_REACHED();
}
int wstatus;
waitpid(pid, &wstatus, 0);
posix_spawn_file_actions_destroy(&action);
// close the write-ends so reading wouldn't block
close(stdout_pipe[1]);
close(stderr_pipe[1]);
auto read_all_from_pipe = [](int pipe[2]) {
auto result_file = Core::File::construct();
if (!result_file->open(pipe[0], Core::OpenMode::ReadOnly, Core::File::ShouldCloseFileDescriptor::Yes)) {
perror("open");
VERIFY_NOT_REACHED();
}
return String::copy(result_file->read_all());
};
if (WEXITSTATUS(wstatus) != 0) {
# ifdef DBG_FAILED_COMMANDS
dbgln("command failed. stderr: {}", read_all_from_pipe(stderr_pipe));
# endif
return {};
}
auto result = read_all_from_pipe(stdout_pipe);
if (result.is_null())
return "";
return result;
}
#endif
}