// wxExecute: the real worker function
long wxExecute(char **argv, int flags, wxProcess *process,
const wxExecuteEnv *env)
{
// for the sync execution, we return -1 to indicate failure, but for async
// case we return 0 which is never a valid PID
//
// we define this as a macro, not a variable, to avoid compiler warnings
// about "ERROR_RETURN_CODE value may be clobbered by fork()"
#define ERROR_RETURN_CODE ((flags & wxEXEC_SYNC) ? -1 : 0)
wxCHECK_MSG( *argv, ERROR_RETURN_CODE, wxT("can't exec empty command") );
#if wxUSE_THREADS
// fork() doesn't mix well with POSIX threads: on many systems the program
// deadlocks or crashes for some reason. Probably our code is buggy and
// doesn't do something which must be done to allow this to work, but I
// don't know what yet, so for now just warn the user (this is the least we
// can do) about it
wxASSERT_MSG( wxThread::IsMain(),
wxT("wxExecute() can be called only from the main thread") );
#endif // wxUSE_THREADS
#if defined(__DARWIN__) && !defined(__WXOSX_IPHONE__)
// wxMacLaunch() only executes app bundles and only does it asynchronously.
// It returns false if the target is not an app bundle, thus falling
// through to the regular code for non app bundles.
if ( !(flags & wxEXEC_SYNC) && wxMacLaunch(argv) )
{
// we don't have any PID to return so just make up something non null
return -1;
}
#endif // __DARWIN__
// this struct contains all information which we use for housekeeping
wxScopedPtr<wxExecuteData> execDataPtr(new wxExecuteData);
wxExecuteData& execData = *execDataPtr;
execData.flags = flags;
execData.process = process;
// create pipes for inter process communication
wxPipe pipeIn, // stdin
pipeOut, // stdout
pipeErr; // stderr
if ( process && process->IsRedirected() )
{
if ( !pipeIn.Create() || !pipeOut.Create() || !pipeErr.Create() )
{
wxLogError( _("Failed to execute '%s'\n"), *argv );
return ERROR_RETURN_CODE;
}
}
// priority: we need to map wxWidgets priority which is in the range 0..100
// to Unix nice value which is in the range -20..19. As there is an odd
// number of elements in our range and an even number in the Unix one, we
// have to do it in this rather ugly way to guarantee that:
// 1. wxPRIORITY_{MIN,DEFAULT,MAX} map to -20, 0 and 19 respectively.
// 2. The mapping is monotonously increasing.
// 3. The mapping is onto the target range.
int prio = process ? int(process->GetPriority()) : int(wxPRIORITY_DEFAULT);
if ( prio <= 50 )
prio = (2*prio)/5 - 20;
else if ( prio < 55 )
prio = 1;
else
prio = (2*prio)/5 - 21;
// fork the process
//
// NB: do *not* use vfork() here, it completely breaks this code for some
// reason under Solaris (and maybe others, although not under Linux)
// But on OpenVMS we do not have fork so we have to use vfork and
// cross our fingers that it works.
#ifdef __VMS
pid_t pid = vfork();
#else
pid_t pid = fork();
#endif
if ( pid == -1 ) // error?
{
wxLogSysError( _("Fork failed") );
return ERROR_RETURN_CODE;
}
else if ( pid == 0 ) // we're in child
{
// NB: we used to close all the unused descriptors of the child here
// but this broke some programs which relied on e.g. FD 1 being
// always opened so don't do it any more, after all there doesn't
// seem to be any real problem with keeping them opened
#if !defined(__VMS)
if ( flags & wxEXEC_MAKE_GROUP_LEADER )
{
// Set process group to child process' pid. Then killing -pid
// of the parent will kill the process and all of its children.
setsid();
}
#endif // !__VMS
#if defined(HAVE_SETPRIORITY)
if ( prio && setpriority(PRIO_PROCESS, 0, prio) != 0 )
{
wxLogSysError(_("Failed to set process priority"));
}
#endif // HAVE_SETPRIORITY
// redirect stdin, stdout and stderr
if ( pipeIn.IsOk() )
{
if ( dup2(pipeIn[wxPipe::Read], STDIN_FILENO) == -1 ||
dup2(pipeOut[wxPipe::Write], STDOUT_FILENO) == -1 ||
dup2(pipeErr[wxPipe::Write], STDERR_FILENO) == -1 )
{
wxLogSysError(_("Failed to redirect child process input/output"));
}
pipeIn.Close();
pipeOut.Close();
pipeErr.Close();
}
// Close all (presumably accidentally) inherited file descriptors to
// avoid descriptor leaks. This means that we don't allow inheriting
// them purposefully but this seems like a lesser evil in wx code.
// Ideally we'd provide some flag to indicate that none (or some?) of
// the descriptors do not need to be closed but for now this is better
// than never closing them at all as wx code never used FD_CLOEXEC.
// TODO: Iterating up to FD_SETSIZE is both inefficient (because it may
// be quite big) and incorrect (because in principle we could
// have more opened descriptions than this number). Unfortunately
// there is no good portable solution for closing all descriptors
// above a certain threshold but non-portable solutions exist for
// most platforms, see [http://stackoverflow.com/questions/899038/
// getting-the-highest-allocated-file-descriptor]
for ( int fd = 0; fd < (int)FD_SETSIZE; ++fd )
{
if ( fd != STDIN_FILENO &&
fd != STDOUT_FILENO &&
fd != STDERR_FILENO )
{
close(fd);
}
}
// Process additional options if we have any
if ( env )
{
// Change working directory if it is specified
if ( !env->cwd.empty() )
wxSetWorkingDirectory(env->cwd);
// Change environment if needed.
//
// NB: We can't use execve() currently because we allow using
// non full paths to wxExecute(), i.e. we want to search for
// the program in PATH. However it just might be simpler/better
// to do the search manually and use execve() envp parameter to
// set up the environment of the child process explicitly
// instead of doing what we do below.
if ( !env->env.empty() )
{
wxEnvVariableHashMap oldenv;
wxGetEnvMap(&oldenv);
// Remove unwanted variables
wxEnvVariableHashMap::const_iterator it;
for ( it = oldenv.begin(); it != oldenv.end(); ++it )
{
if ( env->env.find(it->first) == env->env.end() )
wxUnsetEnv(it->first);
}
// And add the new ones (possibly replacing the old values)
for ( it = env->env.begin(); it != env->env.end(); ++it )
wxSetEnv(it->first, it->second);
}
}
execvp(*argv, argv);
fprintf(stderr, "execvp(");
for ( char **a = argv; *a; a++ )
fprintf(stderr, "%s%s", a == argv ? "" : ", ", *a);
fprintf(stderr, ") failed with error %d!\n", errno);
// there is no return after successful exec()
_exit(-1);
// some compilers complain about missing return - of course, they
// should know that exit() doesn't return but what else can we do if
// they don't?
//
// and, sure enough, other compilers complain about unreachable code
// after exit() call, so we can just always have return here...
#if defined(__VMS) || defined(__INTEL_COMPILER)
return 0;
#endif
}
else // we're in parent
{
// prepare for IO redirection
#if HAS_PIPE_STREAMS
if ( process && process->IsRedirected() )
{
// Avoid deadlocks which could result from trying to write to the
// child input pipe end while the child itself is writing to its
// output end and waiting for us to read from it.
if ( !pipeIn.MakeNonBlocking(wxPipe::Write) )
{
// This message is not terrible useful for the user but what
// else can we do? Also, should we fail here or take the risk
// to continue and deadlock? Currently we choose the latter but
// it might not be the best idea.
wxLogSysError(_("Failed to set up non-blocking pipe, "
"the program might hang."));
#if wxUSE_LOG
wxLog::FlushActive();
#endif
}
wxOutputStream *inStream =
new wxPipeOutputStream(pipeIn.Detach(wxPipe::Write));
const int fdOut = pipeOut.Detach(wxPipe::Read);
wxPipeInputStream *outStream = new wxPipeInputStream(fdOut);
const int fdErr = pipeErr.Detach(wxPipe::Read);
wxPipeInputStream *errStream = new wxPipeInputStream(fdErr);
process->SetPipeStreams(outStream, inStream, errStream);
if ( flags & wxEXEC_SYNC )
{
execData.bufOut.Init(outStream);
execData.bufErr.Init(errStream);
execData.fdOut = fdOut;
execData.fdErr = fdErr;
}
}
#endif // HAS_PIPE_STREAMS
if ( pipeIn.IsOk() )
{
pipeIn.Close();
pipeOut.Close();
pipeErr.Close();
}
if ( !(flags & wxEXEC_SYNC) )
{
// Ensure that the housekeeping data is kept alive, it will be
// destroyed only when the child terminates.
execDataPtr.release();
}
// Put the housekeeping data into the child process lookup table.
// Note that when running asynchronously, if the child has already
// finished this call will delete the execData and call any
// wxProcess's OnTerminate() handler immediately.
execData.OnStart(pid);
// For the asynchronous case we don't have to do anything else, just
// let the process run (if not already finished).
if ( !(flags & wxEXEC_SYNC) )
return pid;
// If we don't need to dispatch any events, things are relatively
// simple and we don't need to delegate to wxAppTraits.
if ( flags & wxEXEC_NOEVENTS )
{
return BlockUntilChildExit(execData);
}
// If we do need to dispatch events, enter a local event loop waiting
// until the child exits. As the exact kind of event loop depends on
// the sort of application we're in (console or GUI), we delegate this
// to wxAppTraits which virtualizes all the differences between the
// console and the GUI programs.
return wxApp::GetValidTraits().WaitForChild(execData);
}
#if !defined(__VMS) && !defined(__INTEL_COMPILER)
return ERROR_RETURN_CODE;
#endif
}
// wxExecute: the real worker function
long wxExecute(char **argv, int flags, wxProcess *process)
{
// for the sync execution, we return -1 to indicate failure, but for async
// case we return 0 which is never a valid PID
//
// we define this as a macro, not a variable, to avoid compiler warnings
// about "ERROR_RETURN_CODE value may be clobbered by fork()"
#define ERROR_RETURN_CODE ((flags & wxEXEC_SYNC) ? -1 : 0)
wxCHECK_MSG( *argv, ERROR_RETURN_CODE, wxT("can't exec empty command") );
#if wxUSE_THREADS
// fork() doesn't mix well with POSIX threads: on many systems the program
// deadlocks or crashes for some reason. Probably our code is buggy and
// doesn't do something which must be done to allow this to work, but I
// don't know what yet, so for now just warn the user (this is the least we
// can do) about it
wxASSERT_MSG( wxThread::IsMain(),
wxT("wxExecute() can be called only from the main thread") );
#endif // wxUSE_THREADS
#if defined(__WXCOCOA__) || ( defined(__WXOSX_MAC__) && wxOSX_USE_COCOA_OR_CARBON )
// wxMacLaunch() only executes app bundles and only does it asynchronously.
// It returns false if the target is not an app bundle, thus falling
// through to the regular code for non app bundles.
if ( !(flags & wxEXEC_SYNC) && wxMacLaunch(argv) )
{
// we don't have any PID to return so just make up something non null
return -1;
}
#endif // __DARWIN__
// this struct contains all information which we use for housekeeping
wxExecuteData execData;
execData.flags = flags;
execData.process = process;
// create pipes
if ( !execData.pipeEndProcDetect.Create() )
{
wxLogError( _("Failed to execute '%s'\n"), *argv );
return ERROR_RETURN_CODE;
}
// pipes for inter process communication
wxPipe pipeIn, // stdin
pipeOut, // stdout
pipeErr; // stderr
if ( process && process->IsRedirected() )
{
if ( !pipeIn.Create() || !pipeOut.Create() || !pipeErr.Create() )
{
wxLogError( _("Failed to execute '%s'\n"), *argv );
return ERROR_RETURN_CODE;
}
}
// fork the process
//
// NB: do *not* use vfork() here, it completely breaks this code for some
// reason under Solaris (and maybe others, although not under Linux)
// But on OpenVMS we do not have fork so we have to use vfork and
// cross our fingers that it works.
#ifdef __VMS
pid_t pid = vfork();
#else
pid_t pid = fork();
#endif
if ( pid == -1 ) // error?
{
wxLogSysError( _("Fork failed") );
return ERROR_RETURN_CODE;
}
else if ( pid == 0 ) // we're in child
{
// NB: we used to close all the unused descriptors of the child here
// but this broke some programs which relied on e.g. FD 1 being
// always opened so don't do it any more, after all there doesn't
// seem to be any real problem with keeping them opened
#if !defined(__VMS) && !defined(__EMX__)
if ( flags & wxEXEC_MAKE_GROUP_LEADER )
{
// Set process group to child process' pid. Then killing -pid
// of the parent will kill the process and all of its children.
setsid();
}
#endif // !__VMS
// reading side can be safely closed but we should keep the write one
// opened, it will be only closed when the process terminates resulting
// in a read notification to the parent
execData.pipeEndProcDetect.Detach(wxPipe::Write);
execData.pipeEndProcDetect.Close();
// redirect stdin, stdout and stderr
if ( pipeIn.IsOk() )
{
if ( dup2(pipeIn[wxPipe::Read], STDIN_FILENO) == -1 ||
dup2(pipeOut[wxPipe::Write], STDOUT_FILENO) == -1 ||
dup2(pipeErr[wxPipe::Write], STDERR_FILENO) == -1 )
{
wxLogSysError(_("Failed to redirect child process input/output"));
}
pipeIn.Close();
pipeOut.Close();
pipeErr.Close();
}
execvp(*argv, argv);
fprintf(stderr, "execvp(");
for ( char **a = argv; *a; a++ )
fprintf(stderr, "%s%s", a == argv ? "" : ", ", *a);
fprintf(stderr, ") failed with error %d!\n", errno);
// there is no return after successful exec()
_exit(-1);
// some compilers complain about missing return - of course, they
// should know that exit() doesn't return but what else can we do if
// they don't?
//
// and, sure enough, other compilers complain about unreachable code
// after exit() call, so we can just always have return here...
#if defined(__VMS) || defined(__INTEL_COMPILER)
return 0;
#endif
}
else // we're in parent
{
// save it for WaitForChild() use
execData.pid = pid;
if (execData.process)
execData.process->SetPid(pid); // and also in the wxProcess
// prepare for IO redirection
#if HAS_PIPE_INPUT_STREAM
// the input buffer bufOut is connected to stdout, this is why it is
// called bufOut and not bufIn
wxStreamTempInputBuffer bufOut,
bufErr;
if ( process && process->IsRedirected() )
{
wxOutputStream *inStream =
new wxFileOutputStream(pipeIn.Detach(wxPipe::Write));
const int fdOut = pipeOut.Detach(wxPipe::Read);
wxPipeInputStream *outStream = new wxPipeInputStream(fdOut);
const int fdErr = pipeErr.Detach(wxPipe::Read);
wxPipeInputStream *errStream = new wxPipeInputStream(fdErr);
process->SetPipeStreams(outStream, inStream, errStream);
bufOut.Init(outStream);
bufErr.Init(errStream);
execData.bufOut = &bufOut;
execData.bufErr = &bufErr;
execData.fdOut = fdOut;
execData.fdErr = fdErr;
}
#endif // HAS_PIPE_INPUT_STREAM
if ( pipeIn.IsOk() )
{
pipeIn.Close();
pipeOut.Close();
pipeErr.Close();
}
// we want this function to work even if there is no wxApp so ensure
// that we have a valid traits pointer
wxConsoleAppTraits traitsConsole;
wxAppTraits *traits = wxTheApp ? wxTheApp->GetTraits() : NULL;
if ( !traits )
traits = &traitsConsole;
return traits->WaitForChild(execData);
}
#if !defined(__VMS) && !defined(__INTEL_COMPILER)
return ERROR_RETURN_CODE;
#endif
}
// wxExecute: the real worker function
long wxExecute(char **argv, int flags, wxProcess *process,
const wxExecuteEnv *env)
{
// for the sync execution, we return -1 to indicate failure, but for async
// case we return 0 which is never a valid PID
//
// we define this as a macro, not a variable, to avoid compiler warnings
// about "ERROR_RETURN_CODE value may be clobbered by fork()"
#define ERROR_RETURN_CODE ((flags & wxEXEC_SYNC) ? -1 : 0)
wxCHECK_MSG( *argv, ERROR_RETURN_CODE, wxT("can't exec empty command") );
#if wxUSE_THREADS
// fork() doesn't mix well with POSIX threads: on many systems the program
// deadlocks or crashes for some reason. Probably our code is buggy and
// doesn't do something which must be done to allow this to work, but I
// don't know what yet, so for now just warn the user (this is the least we
// can do) about it
wxASSERT_MSG( wxThread::IsMain(),
wxT("wxExecute() can be called only from the main thread") );
#endif // wxUSE_THREADS
#if defined(__WXCOCOA__) || ( defined(__WXOSX_MAC__) && wxOSX_USE_COCOA_OR_CARBON )
// wxMacLaunch() only executes app bundles and only does it asynchronously.
// It returns false if the target is not an app bundle, thus falling
// through to the regular code for non app bundles.
if ( !(flags & wxEXEC_SYNC) && wxMacLaunch(argv) )
{
// we don't have any PID to return so just make up something non null
return -1;
}
#endif // __DARWIN__
// this struct contains all information which we use for housekeeping
wxExecuteData execData;
execData.flags = flags;
execData.process = process;
// create pipes
if ( !execData.pipeEndProcDetect.Create() )
{
wxLogError( _("Failed to execute '%s'\n"), *argv );
return ERROR_RETURN_CODE;
}
// pipes for inter process communication
wxPipe pipeIn, // stdin
pipeOut, // stdout
pipeErr; // stderr
if ( process && process->IsRedirected() )
{
if ( !pipeIn.Create() || !pipeOut.Create() || !pipeErr.Create() )
{
wxLogError( _("Failed to execute '%s'\n"), *argv );
return ERROR_RETURN_CODE;
}
}
// fork the process
//
// NB: do *not* use vfork() here, it completely breaks this code for some
// reason under Solaris (and maybe others, although not under Linux)
// But on OpenVMS we do not have fork so we have to use vfork and
// cross our fingers that it works.
#ifdef __VMS
pid_t pid = vfork();
#else
pid_t pid = fork();
#endif
if ( pid == -1 ) // error?
{
wxLogSysError( _("Fork failed") );
return ERROR_RETURN_CODE;
}
else if ( pid == 0 ) // we're in child
{
// NB: we used to close all the unused descriptors of the child here
// but this broke some programs which relied on e.g. FD 1 being
// always opened so don't do it any more, after all there doesn't
// seem to be any real problem with keeping them opened
#if !defined(__VMS) && !defined(__EMX__)
if ( flags & wxEXEC_MAKE_GROUP_LEADER )
{
// Set process group to child process' pid. Then killing -pid
// of the parent will kill the process and all of its children.
setsid();
}
#endif // !__VMS
// redirect stdin, stdout and stderr
if ( pipeIn.IsOk() )
{
if ( dup2(pipeIn[wxPipe::Read], STDIN_FILENO) == -1 ||
dup2(pipeOut[wxPipe::Write], STDOUT_FILENO) == -1 ||
dup2(pipeErr[wxPipe::Write], STDERR_FILENO) == -1 )
{
wxLogSysError(_("Failed to redirect child process input/output"));
}
pipeIn.Close();
pipeOut.Close();
pipeErr.Close();
}
// Close all (presumably accidentally) inherited file descriptors to
// avoid descriptor leaks. This means that we don't allow inheriting
// them purposefully but this seems like a lesser evil in wx code.
// Ideally we'd provide some flag to indicate that none (or some?) of
// the descriptors do not need to be closed but for now this is better
// than never closing them at all as wx code never used FD_CLOEXEC.
// Note that while the reading side of the end process detection pipe
// can be safely closed, we should keep the write one opened, it will
// be only closed when the process terminates resulting in a read
// notification to the parent
const int fdEndProc = execData.pipeEndProcDetect.Detach(wxPipe::Write);
execData.pipeEndProcDetect.Close();
// TODO: Iterating up to FD_SETSIZE is both inefficient (because it may
// be quite big) and incorrect (because in principle we could
// have more opened descriptions than this number). Unfortunately
// there is no good portable solution for closing all descriptors
// above a certain threshold but non-portable solutions exist for
// most platforms, see [http://stackoverflow.com/questions/899038/
// getting-the-highest-allocated-file-descriptor]
for ( int fd = 0; fd < (int)FD_SETSIZE; ++fd )
{
if ( fd != STDIN_FILENO &&
fd != STDOUT_FILENO &&
fd != STDERR_FILENO &&
fd != fdEndProc )
{
close(fd);
}
}
// Process additional options if we have any
if ( env )
{
// Change working directory if it is specified
if ( !env->cwd.empty() )
wxSetWorkingDirectory(env->cwd);
// Change environment if needed.
//
// NB: We can't use execve() currently because we allow using
// non full paths to wxExecute(), i.e. we want to search for
// the program in PATH. However it just might be simpler/better
// to do the search manually and use execve() envp parameter to
// set up the environment of the child process explicitly
// instead of doing what we do below.
if ( !env->env.empty() )
{
wxEnvVariableHashMap oldenv;
wxGetEnvMap(&oldenv);
// Remove unwanted variables
wxEnvVariableHashMap::const_iterator it;
for ( it = oldenv.begin(); it != oldenv.end(); ++it )
{
if ( env->env.find(it->first) == env->env.end() )
wxUnsetEnv(it->first);
}
// And add the new ones (possibly replacing the old values)
for ( it = env->env.begin(); it != env->env.end(); ++it )
wxSetEnv(it->first, it->second);
}
}
execvp(*argv, argv);
fprintf(stderr, "execvp(");
for ( char **a = argv; *a; a++ )
fprintf(stderr, "%s%s", a == argv ? "" : ", ", *a);
fprintf(stderr, ") failed with error %d!\n", errno);
// there is no return after successful exec()
_exit(-1);
// some compilers complain about missing return - of course, they
// should know that exit() doesn't return but what else can we do if
// they don't?
//
// and, sure enough, other compilers complain about unreachable code
// after exit() call, so we can just always have return here...
#if defined(__VMS) || defined(__INTEL_COMPILER)
return 0;
#endif
}
else // we're in parent
{
// save it for WaitForChild() use
execData.pid = pid;
if (execData.process)
execData.process->SetPid(pid); // and also in the wxProcess
// prepare for IO redirection
#if HAS_PIPE_STREAMS
// the input buffer bufOut is connected to stdout, this is why it is
// called bufOut and not bufIn
wxStreamTempInputBuffer bufOut,
bufErr;
if ( process && process->IsRedirected() )
{
// Avoid deadlocks which could result from trying to write to the
// child input pipe end while the child itself is writing to its
// output end and waiting for us to read from it.
if ( !pipeIn.MakeNonBlocking(wxPipe::Write) )
{
// This message is not terrible useful for the user but what
// else can we do? Also, should we fail here or take the risk
// to continue and deadlock? Currently we choose the latter but
// it might not be the best idea.
wxLogSysError(_("Failed to set up non-blocking pipe, "
"the program might hang."));
#if wxUSE_LOG
wxLog::FlushActive();
#endif
}
wxOutputStream *inStream =
new wxPipeOutputStream(pipeIn.Detach(wxPipe::Write));
const int fdOut = pipeOut.Detach(wxPipe::Read);
wxPipeInputStream *outStream = new wxPipeInputStream(fdOut);
const int fdErr = pipeErr.Detach(wxPipe::Read);
wxPipeInputStream *errStream = new wxPipeInputStream(fdErr);
process->SetPipeStreams(outStream, inStream, errStream);
bufOut.Init(outStream);
bufErr.Init(errStream);
execData.bufOut = &bufOut;
execData.bufErr = &bufErr;
execData.fdOut = fdOut;
execData.fdErr = fdErr;
}
#endif // HAS_PIPE_STREAMS
if ( pipeIn.IsOk() )
{
pipeIn.Close();
pipeOut.Close();
pipeErr.Close();
}
// we want this function to work even if there is no wxApp so ensure
// that we have a valid traits pointer
wxConsoleAppTraits traitsConsole;
wxAppTraits *traits = wxTheApp ? wxTheApp->GetTraits() : NULL;
if ( !traits )
traits = &traitsConsole;
return traits->WaitForChild(execData);
}
#if !defined(__VMS) && !defined(__INTEL_COMPILER)
return ERROR_RETURN_CODE;
#endif
}
