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// *****************************************************************************
// * This file is part of the FreeFileSync project. It is distributed under *
// * GNU General Public License: https://www.gnu.org/licenses/gpl-3.0 *
// * Copyright (C) Zenju (zenju AT freefilesync DOT org) - All Rights Reserved *
// *****************************************************************************
#ifndef SHELL_EXECUTE_H_23482134578134134
#define SHELL_EXECUTE_H_23482134578134134
#include "file_error.h"
#include <unistd.h> //fork()
#include <stdlib.h> //::system()
namespace zen
{
//launch commandline and report errors via popup dialog
//Windows: COM needs to be initialized before calling this function!
enum class ExecutionType
{
sync,
async
};
namespace
{
int shellExecute(const Zstring& command, ExecutionType type, bool hideConsole) //throw FileError
{
/*
we cannot use wxExecute due to various issues:
- screws up encoding on OS X for non-ASCII characters
- does not provide any reasonable error information
- uses a zero-sized dummy window as a hack to keep focus which leaves a useless empty icon in ALT-TAB list in Windows
*/
if (type == ExecutionType::sync)
{
//Posix ::system() - execute a shell command
const int rv = ::system(command.c_str()); //do NOT use std::system as its documentation says nothing about "WEXITSTATUS(rv)", etc...
if (rv == -1 || WEXITSTATUS(rv) == 127)
throw FileError(_("Incorrect command line:") + L' ' + utfTo<std::wstring>(command));
//https://linux.die.net/man/3/system "In case /bin/sh could not be executed, the exit status will be that of a command that does exit(127)"
//Bonus: For an incorrect command line /bin/sh also returns with 127!
return /*int exitCode = */ WEXITSTATUS(rv);
}
else
{
//follow implemenation of ::system() except for waitpid():
const pid_t pid = ::fork();
if (pid < 0) //pids are never negative, empiric proof: https://linux.die.net/man/2/wait
THROW_LAST_FILE_ERROR(_("Incorrect command line:") + L' ' + utfTo<std::wstring>(command), L"fork");
if (pid == 0) //child process
{
const char* argv[] = { "sh", "-c", command.c_str(), nullptr };
/*int rv =*/::execv("/bin/sh", const_cast<char**>(argv));
//safe to cast away const: http://pubs.opengroup.org/onlinepubs/9699919799/functions/exec.html
// "The statement about argv[] and envp[] being constants is included to make explicit to future
// writers of language bindings that these objects are completely constant. Due to a limitation of
// the ISO C standard, it is not possible to state that idea in standard C."
//"execv() only returns if an error has occurred. The return value is -1, and errno is set to indicate the error."
::_exit(127); //[!] avoid flushing I/O buffers or doing other clean up from child process like with "exit(127)"!
}
//else //parent process
return 0;
}
}
std::string getCommandOutput(const Zstring& command) //throw SysError
{
//https://developer.apple.com/library/archive/documentation/System/Conceptual/ManPages_iPhoneOS/man3/popen.3.html
FILE* pipe = ::popen(command.c_str(), "r");
if (!pipe)
THROW_LAST_SYS_ERROR(L"popen");
ZEN_ON_SCOPE_EXIT(::pclose(pipe));
std::string output;
const size_t blockSize = 64 * 1024;
do
{
output.resize(output.size() + blockSize);
//caveat: SIGCHLD is NOT ignored under macOS debugger => EINTR inside fread() => call ::siginterrupt(SIGCHLD, false) during startup
const size_t bytesRead = ::fread(&*(output.end() - blockSize), 1, blockSize, pipe);
if (::ferror(pipe))
THROW_LAST_SYS_ERROR(L"fread");
if (bytesRead > blockSize)
throw SysError(L"fread: buffer overflow");
if (bytesRead < blockSize)
output.resize(output.size() - (blockSize - bytesRead)); //caveat: unsigned arithmetics
}
while (!::feof(pipe));
return output;
}
}
inline
void openWithDefaultApplication(const Zstring& itemPath) //throw FileError
{
shellExecute("xdg-open \"" + itemPath + '"', ExecutionType::async, false /*hideConsole*/); //throw FileError
}
}
#endif //SHELL_EXECUTE_H_23482134578134134
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