FileLock.cpp

Example program for advisory POSIX and BSD file locking. Should be installed as ui-utilcpp-filelock along with the library.

// Local
#include "config.h"
// STDC++
#include <iostream>
#include <string>
// POSIX C
// C++ Libraries
#include <ui-utilcpp/File.hpp>
#include <ui-utilcpp/Misc.hpp>
#include <ui-utilcpp/Thread.hpp>
using UI::Util::MutexLock;
using UI::Util::FileDescriptor;
using UI::Util::PosixFileMutex;
using UI::Util::BSDFileMutex;
template <typename M>
int lock(const std::string & fileName)
{
int exitCode(0);
try
{
M m(fileName);
MutexLock<M> l(m, false);
std::cout << "Locked (do some input to finish): " << fileName << std::flush;
std::string dummy;
std::cin >> dummy;
}
catch(typename MutexLock<M>::Exception const & ex)
{
std::cerr << "MutexLock exception: " << ex.getCode() << ": " << ex.what() << std::endl;
exitCode = 1;
}
catch(typename M::Exception const & ex)
{
std::cerr << "FileLock exception: " << ex.getCode() << ": " << ex.what() << std::endl;
exitCode = 2;
}
catch(std::exception const & ex)
{
std::cerr << "std::exception: " << ex.what() << std::endl;
exitCode = 3;
}
catch(...)
{
std::cerr << "ERROR: Unknown exception!" << std::endl;
exitCode = 4;
}
return(exitCode);
}
int main(int argc, char *argv[])
{
if (argc != 3)
{
std::cerr << "Lock a file via POSIX or BSD advisory locking." << std::endl << std::endl;
std::cerr << "Usage: " << argv[0] << " posix|bsd <file>" << std::endl << std::endl;
std::cerr << "Exit Codes: 0 for success, 1 if file was locked, 2 if creat(2) failed, 3 for unknown error." << std::endl;
std::cerr << "Exit Codes: 42 for some other error." << std::endl;
return(42);
}
if ((std::string) argv[1] == "posix")
{
return(lock<PosixFileMutex>(argv[2]));
}
else if ((std::string) argv[1] == "bsd")
{
return(lock<BSDFileMutex>(argv[2]));
}
else
{
std::cerr << "Argument 1 must be either \"posix\" or \"bsd\"." << std::endl;
return(42);
}
}
File.hpp
File, descriptors and sockets.
Misc.hpp
Thread.hpp
Thread, descriptors and sockets.
UI::Util::BSDFileMutex
Mutex For BSD Advisory File Locking.
Definition File.hpp:268
UI::Util::FileDescriptor
File Descriptor Holder Class.
Definition File.hpp:104
UI::Util::MutexLock
Mutex Lock class; an object of this class will guard a scope.
Definition Misc.hpp:182
UI::Util::PosixFileMutex
Mutex For Posix Advisory File Locking.
Definition File.hpp:233