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C++ Library containing a lot of needful things: Stack Trace, Command Line Parser, Resource Handling, Configuration Files, Unix Command Execution, Directories, Regular Expressions, Tokenizer, Function Trace, Standard Extensions.
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mrw-cxx/mrw/exec.cpp

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/** @file
$Id$
$Date$
$Author$
@copy © Marc Wäckerlin
@license LGPL, see file <a href="license.html">COPYING</a>
$Log$
Revision 1.14 2005/11/29 12:39:42 marc
make it compilable with gcc 4.0.2 and newer doxygen
Revision 1.13 2005/04/20 18:32:14 marc
*** empty log message ***
Revision 1.12 2005/04/20 18:12:55 marc
added kill() for PartialExec
Revision 1.11 2005/04/19 18:48:00 marc
new feature PartialExec
Revision 1.10 2005/03/14 16:26:34 marc
bugs have been fixed a long time ago, now no more in buglist
Revision 1.9 2004/12/20 07:40:35 marc
documentation improved, new grouping
Revision 1.8 2004/12/18 21:00:09 marc
everything is ok, when pipes are non blocking on parent's side and blocking on client's side, and select is not used (not necessary for non blocking IO)
Revision 1.7 2004/12/17 17:38:57 marc
it works perfectly with blocking pipes and buffer size of 1
Revision 1.6 2004/12/17 16:28:51 marc
stable implementation with select for both executes
Revision 1.5 2004/12/14 20:30:09 marc
added possibility to pass string to stdin of child process
Revision 1.4 2004/08/28 16:21:25 marc
mrw-c++-0.92 (mrw)
- new file: version.cpp
- new file header for all sources
- work around warning in mrw::auto<T>
- possibility to compile without log4cxx
- work around bugs in demangle.h and libiberty.h
- corrections in documentation
- added simple tracing mechanism
- more warnings
- small corrections in Auto<>::Free and a new test for it
- possibility to compile without stack trace
*/
#include <mrw/exec.hpp>
#include <mrw/unistd.hpp>
#include <mrw/exception.hpp>
#include <sys/wait.h> // waitpid
#include <unistd.h> // fork, exec
#include <string.h> // memcpy
#include <assert.h> // assert
#include <sys/types.h> // kill
#include <signal.h> // kill
//=========================================================== ExecutionFailedExc
//------------------------------------------------------------------------------
mrw::ExecutionFailedExc::ExecutionFailedExc(const std::string& w,
const std::string& c)
throw(std::bad_exception):
_what(std::string("mrw::Exec: command execution failed\n")+
std::string(" failed command was: \""+c+"\"\n")+
std::string(" error was: \"")+w+'"') {
/**
@c what looks like:
@verbatim
mrw::Exec: command execution failed
failed command was: "/bin/OOOOPS -v -q --crash"
error was: "execution failed"
@endverbatim
*/
}
//========================================================================== Cmd
//------------------------------------------------------------------------------
mrw::Cmd::Cmd(const std::string& c) throw(std::bad_exception) {
_cmd.push_back(c);
}
//------------------------------------------------------------------------------
mrw::Cmd& mrw::Cmd::operator,(const std::string& arg)
throw(std::bad_exception) {
_cmd.push_back(arg);
return *this;
}
//------------------------------------------------------------------------------
mrw::Cmd& mrw::Cmd::operator<<(const std::string& arg)
throw(std::bad_exception) {
_cmd.push_back(arg);
return *this;
}
//------------------------------------------------------------------------------
mrw::Cmd::operator std::string() const throw(std::bad_exception) {
ArgList::const_iterator it(_cmd.begin());
std::string c(*it);
while (++it!=_cmd.end()) c+=' '+*it;
return c;
}
//------------------------------------------------------------------------------
mrw::Cmd::operator mrw::Exec() const throw(std::bad_exception) {
return mrw::Exec(*this);
}
//------------------------------------------------------------------------------
mrw::Cmd::operator mrw::PartialExec() const throw(std::bad_exception) {
return mrw::PartialExec(*this);
}
//------------------------------------------------------------------------------
mrw::Exec mrw::Cmd::execute(bool exc) const throw(std::exception) {
return mrw::Exec(*this).execute(exc);
}
//------------------------------------------------------------------------------
mrw::Exec mrw::Cmd::execute(const std::string& input, bool exc) const
throw(std::exception) {
return mrw::Exec(*this).execute(input, exc);
}
//------------------------------------------------------------------------------
mrw::PartialExec mrw::Cmd::start(bool useInput) const throw(std::exception) {
return mrw::PartialExec(*this).start(useInput);
}
//------------------------------------------------------------------------------
const char* mrw::Cmd::path() const throw(std::bad_exception) {
return _cmd.front().c_str();
}
//------------------------------------------------------------------------------
char** mrw::Cmd::args() const throw(std::bad_exception) {
if (_cmd.size()==0) return 0;
char** array = new char*[_cmd.size()+1];
int i(0);
for (ArgList::const_iterator it(_cmd.begin()); it!=_cmd.end(); ++it)
memcpy(array[i++]=new char[it->size()+1], it->c_str(), it->size()+1);
array[i] = 0;
return array;
}
//========================================================================= Exec
//------------------------------------------------------------------------------
mrw::Exec::Exec(const mrw::Cmd& c) throw(std::bad_exception):
_cmd(new mrw::Cmd(c)), _success(false) {
}
//------------------------------------------------------------------------------
mrw::Exec::Exec(const mrw::Exec& e) throw(std::bad_exception):
_cmd(new mrw::Cmd(*e._cmd)),
_res(e._res), _err(e._err), _success(e._success) {
}
//------------------------------------------------------------------------------
mrw::Exec::~Exec() throw() {
delete _cmd;
}
//------------------------------------------------------------------------------
mrw::Exec& mrw::Exec::operator=(const mrw::Exec& e) throw(std::bad_exception) {
if (this==&e) return *this;
*_cmd=*e._cmd; _res=e._res; _err=e._err; _success=e._success;
return *this;
}
//------------------------------------------------------------------------------
mrw::Exec& mrw::Exec::execute(bool exc) throw(std::exception) {
/** This method calls @c fork, sets up a pipe connection to pass @c
stdout and @c stderr from the child process to the parent
process using mrw::Pipe and calls @c execvp to execute the
program. */
_success = false;
_res = _err = "";
mrw::Pipe stdOut(mrw::Pipe::block_output), stdErr(mrw::Pipe::block_output);
if (!stdOut || !stdErr)
throw mrw::ExecutionFailedExc("cannot create pipe", *_cmd);
pid_t pid(fork());
if (pid<0)
throw ExecutionFailedExc("cannot fork", *_cmd);
if (pid) { // parent
stdOut.close_out();
stdErr.close_out();
if (!stdOut || !stdErr)
throw ExecutionFailedExc("cannot close pipe", *_cmd);
ssize_t num1(1), num2(1);
char buf[4096];
int res(0), s(0);
/* It sometimes did not get the whole input since I changed to non
blocking pipes. Now I have found the solution to the problems:
Non blocking IO does not work in conjunction with select!
Also the pipe must not be nonblocking on both ends, but only on
one. */
while (num1||num2||!res) try { // not end of files or child terminated
if (!res && (res=waitpid(pid, &s, WNOHANG)))
if (res!=pid || WIFEXITED(s)!=0 && WEXITSTATUS(s)!=0)
throw ExecutionFailedExc("execution failed", *_cmd);
if (num1<=0&&num2<=0) usleep(10000); // nothing to read last time
// check and handle stdout
if (num1 && (num1=read(stdOut.istream(), buf, sizeof(buf)))>0)
_res += std::string(buf, num1);
else if (num1==-1)
if (errno!=EINTR&&errno!=EAGAIN)
throw ExecutionFailedExc("readin stdout", *_cmd);
else
num1 = 1;
// check and handle stderr
if (num2 && (num2=read(stdErr.istream(), buf, sizeof(buf)))>0)
_err += std::string(buf, num2);
else if (num2==-1)
if (errno!=EINTR&&errno!=EAGAIN)
throw ExecutionFailedExc("readin stderr", *_cmd);
else
num2 = 1;
} catch (...) {
_success = false;
if (exc) throw;
return *this;
}
} else { // child
stdOut.close_in();
stdErr.close_in();
stdOut.connect_cout();
stdErr.connect_cerr();
execvp(_cmd->path(), _cmd->args());
exit(1); // execute failed
}
_success = true;
return *this;
}
//------------------------------------------------------------------------------
mrw::Exec& mrw::Exec::execute(const std::string& input, bool exc)
throw(std::exception) {
/// @c input length must be smaller than @c SSIZE_MAX.
/// I'll only add support for longer strings upon request.
assert(input.size()<=SSIZE_MAX &&
"sdin input exeeds C library limit in mrw::Exec "
"please contact the author of the library");
/** This method calls @c fork, sets up a pipe connection to pass @c
stdin, @c stdout and @c stderr between the child process and the
parent process using mrw::Pipe and calls @c execvp to execute
the program. */
_success = false;
_res = _err = "";
mrw::Pipe stdIn(mrw::Pipe::block_input),
stdOut(mrw::Pipe::block_output), stdErr(mrw::Pipe::block_output);
if (!stdIn || !stdOut || !stdErr)
throw mrw::ExecutionFailedExc("cannot create pipe", *_cmd);
pid_t pid(fork());
if (pid<0) throw ExecutionFailedExc("cannot fork", *_cmd);
if (pid) { // parent
stdIn.close_in();
stdOut.close_out();
stdErr.close_out();
if (!stdIn || !stdOut || !stdErr)
throw ExecutionFailedExc("cannot close pipes", *_cmd);
ssize_t num0(1), num1(1), num2(1);
std::string in(input);
char buf[4096];
int res(0), s(0);
/* It sometimes did not get the whole input since I changed to non
blocking pipes. Now I have found the solution to the problems:
Non blocking IO does not work in conjunction with select! Also
the pipe must not be nonblocking on both ends, but only on
one. */
while (num0||num1||num2||!res) try { // not end of files or child terminated
if (!res && (res=waitpid(pid, &s, WNOHANG)))
if (res!=pid || WIFEXITED(s)!=0 && WEXITSTATUS(s)!=0)
throw ExecutionFailedExc("execution failed", *_cmd);
if (num0<=0&&num1<=0&&num2<=0) usleep(10000); // no activity last time
// check and handle stdin
if (num0 && (num0=write(stdIn.ostream(), in.c_str(), in.size()))>0) {
if ((unsigned int)num0<in.size())
in = in.substr(num0);
else if ((unsigned int)num0==in.size())
num0=0, stdIn.close_out();
} else if (num0==-1)
if (errno!=EINTR&&errno!=EAGAIN)
throw ExecutionFailedExc("writing stdin", *_cmd);
else
num0 = 1;
// check and handle stdout
if (num1 && (num1=read(stdOut.istream(), buf, sizeof(buf)))>0)
_res += std::string(buf, num1);
else if (num1==-1)
if (errno!=EINTR&&errno!=EAGAIN)
throw ExecutionFailedExc("readin stdout", *_cmd);
else
num1 = 1;
// check and handle stderr
if (num2 && (num2=read(stdErr.istream(), buf, sizeof(buf)))>0)
_err += std::string(buf, num2);
else if (num2==-1)
if (errno!=EINTR&&errno!=EAGAIN)
throw ExecutionFailedExc("readin stderr", *_cmd);
else
num2 = 1;
} catch (...) {
_success = false;
if (exc) throw;
return *this;
}
} else { // child
stdIn.close_out();
stdOut.close_in();
stdErr.close_in();
stdIn.connect_cin();
stdOut.connect_cout();
stdErr.connect_cerr();
execvp(_cmd->path(), _cmd->args());
exit(1); // execute failed
}
_success = true;
return *this;
}
//------------------------------------------------------------------------------
mrw::Exec& mrw::Exec::operator>>(std::string& res) throw(std::exception) {
execute();
res += _res;
return *this;
}
//------------------------------------------------------------------------------
mrw::Exec::operator std::string&() throw(std::exception) {
if (!_success) execute();
return _res;
}
//------------------------------------------------------------------------------
mrw::Exec::operator bool() throw(std::bad_exception) {
return _success;
}
//------------------------------------------------------------------------------
std::string& mrw::Exec::result() throw(std::exception) {
if (!_success) execute();
return _res;
}
//------------------------------------------------------------------------------
std::string& mrw::Exec::error() throw(std::exception) {
if (!_success) execute();
return _err;
}
//------------------------------------------------------------------------------
bool mrw::Exec::success() throw(std::bad_exception) {
return _success;
}
//================================================================== PartialExec
//------------------------------------------------------------------------------
mrw::PartialExec::PartialExec(const mrw::Cmd& c) throw(std::bad_exception):
Exec(c), _finished(true), _finish(false) {
}
//------------------------------------------------------------------------------
mrw::PartialExec::PartialExec(mrw::PartialExec& e)
throw(std::bad_exception):
Exec(e), _finished(e._finished), _finish(e._finish),
_stdIn(e._stdIn), _stdOut(e._stdOut), _stdErr(e._stdErr), _input(e._input),
_num0(e._num0), _num1(e._num1), _num2(e._num2),
_lastPid(e._lastPid), _pid(e._pid) {
e._finished = true;
}
//------------------------------------------------------------------------------
mrw::PartialExec::PartialExec(const mrw::PartialExec& e)
throw(std::bad_exception):
Exec(e), _finished(e._finished), _finish(e._finish),
_input(e._input),
_num0(e._num0), _num1(e._num1), _num2(e._num2),
_lastPid(e._lastPid), _pid(e._pid) {
/** @warning @c const is casted away */
mrw::PartialExec& nonConstE(const_cast<mrw::PartialExec&>(e));
_stdIn = nonConstE._stdIn;
_stdOut = nonConstE._stdOut;
_stdErr = nonConstE._stdErr;
nonConstE._finished = true;
nonConstE._finish = false;
}
//------------------------------------------------------------------------------
mrw::PartialExec& mrw::PartialExec::operator=(mrw::PartialExec& e)
throw(std::bad_exception) {
if (this==&e) return *this;
*_cmd=*e._cmd; _res=e._res; _err=e._err; _success=e._success;
_finished = e._finished;
_finish = e._finish;
_stdIn = e._stdIn; _stdOut = e._stdOut; _stdErr = e._stdErr;
_input = e._input; _num0 = e._num0; _num1 = e._num1; _num2 = e._num2;
_lastPid = e._lastPid;
_pid = e._pid;
e._finished = true;
e._finish = false;
return *this;
}
//------------------------------------------------------------------------------
mrw::PartialExec& mrw::PartialExec::finish() throw() {
_finish = true;
return *this;
}
//------------------------------------------------------------------------------
bool mrw::PartialExec::finished() throw() {
return _finished;
}
//------------------------------------------------------------------------------
mrw::PartialExec& mrw::PartialExec::start(bool useInput)
throw(std::exception) {
if (!_finished) throw mrw::runtime_error("running process not yet finished");
/** This method calls @c fork, sets up a pipe connection to pass @c
stdin, @c stdout and @c stderr between the child process and the
parent process using mrw::Pipe and calls @c execvp to execute
the program. */
_success = false;
_finish = !useInput;
_input = "";
_res = _err = "";
_stdIn = std::auto_ptr<mrw::Pipe>(new mrw::Pipe(mrw::Pipe::block_input));
_stdOut = std::auto_ptr<mrw::Pipe>(new mrw::Pipe(mrw::Pipe::block_output));
_stdErr = std::auto_ptr<mrw::Pipe>(new mrw::Pipe(mrw::Pipe::block_output));
if (!*_stdIn || !*_stdOut || !*_stdErr)
throw mrw::ExecutionFailedExc("cannot create pipe", *_cmd);
_lastPid = 0;
_pid = fork();
if (_pid<0) throw ExecutionFailedExc("cannot fork", *_cmd);
if (_pid) { // parent
_stdIn->close_in();
_stdOut->close_out();
_stdErr->close_out();
if (!*_stdIn || !*_stdOut || !*_stdErr)
throw ExecutionFailedExc("cannot close pipes", *_cmd);
_num0 = _num1 = _num2 = 1;
_finished = false;
} else { // child
_stdIn->close_out();
_stdOut->close_in();
_stdErr->close_in();
_stdIn->connect_cin();
_stdOut->connect_cout();
_stdErr->connect_cerr();
execvp(_cmd->path(), _cmd->args());
exit(1); // execute failed
}
_success = true;
return *this;
}
//------------------------------------------------------------------------------
std::pair<std::string, std::string>
mrw::PartialExec::read(const std::string& input, bool exc)
throw(std::exception) {
std::pair<std::string, std::string> output;
/** @note @c input length must be smaller than @c SSIZE_MAX.
I'll only add support for longer strings upon request. */
assert(input.size()<=SSIZE_MAX &&
"sdin input exeeds C library limit in mrw::Exec "
"please contact the author of the library");
/** @warning After calling finish(), it is forbidden to pass
any @c input string, it must then always be empty,
because the pipe is already closed! */
assert(!(_finish && input.size()) &&
"after calling PartialExec::finish(), it is forbidden "
"to pass new input text, because the pipe is already "
"closed! this is a programming but that must be solved!");
_input += input;
/* It sometimes did not get the whole input since I changed to non
blocking pipes. Now I have found the solution to the problems:
Non blocking IO does not work in conjunction with select! Also
the pipe must not be nonblocking on both ends, but only on
one. */
if (!_finished) try { // not finished
char buf[4096];
int s(0);
if (!_lastPid && (_lastPid=waitpid(_pid, &s, WNOHANG))) {
if (_lastPid!=_pid || WIFEXITED(s)!=0 && WEXITSTATUS(s)!=0)
throw ExecutionFailedExc("execution failed", *_cmd);
}
// check and handle stdin
if (_input.size() && _num0!=-1 &&
(_num0=write(_stdIn->ostream(), _input.c_str(), _input.size()))>0) {
if ((unsigned int)_num0<_input.size())
_input = _input.substr(_num0);
else if ((unsigned int)_num0==_input.size())
_input.clear();
} else if (_num0==-1)
if (errno!=EINTR&&errno!=EAGAIN)
throw ExecutionFailedExc("writing stdin", *_cmd);
else
_num0 = 1;
// check and handle stdout
if (_num1 && (_num1=::read(_stdOut->istream(), buf, sizeof(buf)))>0)
_res += output.first=std::string(buf, _num1);
else if (_num1==-1)
if (errno!=EINTR&&errno!=EAGAIN)
throw ExecutionFailedExc("readin stdout", *_cmd);
else
_num1 = 1;
// check and handle stderr
if (_num2 && (_num2=::read(_stdErr->istream(), buf, sizeof(buf)))>0)
_err += output.second=std::string(buf, _num2);
else if (_num2==-1)
if (errno!=EINTR&&errno!=EAGAIN)
throw ExecutionFailedExc("readin stderr", *_cmd);
else
_num2 = 1;
if (_finish && !_input.size()) {
_stdIn->close_out();
_num0 = 0;
}
_finished = _finish && !_input.size() && !_num1 && !_num2 && _lastPid;
} catch (mrw::exception& x) {
_finished = true;
_success = false;
if (exc) throw;
return output;
}
if (_finished) _success = true;
return output;
}
//------------------------------------------------------------------------------
mrw::PartialExec& mrw::PartialExec::terminate() throw() {
::kill(_pid, SIGTERM);
return *this;
}
//------------------------------------------------------------------------------
mrw::PartialExec& mrw::PartialExec::kill() throw() {
::kill(_pid, SIGKILL);
return *this;
}