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.
You can not select more than 25 topics Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.

298 lines
9.7 KiB

/** @file
$Id$
$Date$
$Author$
@copy © Marc Wäckerlin
@license LGPL, see file <a href="license.html">COPYING</a>
$Log$
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
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
*/
}
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::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);
}
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;
}
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);
21 years ago
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
21 years ago
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 && (errno!=EINTR&&errno!=EAGAIN))
throw ExecutionFailedExc("readin stdout", *_cmd);
// check and handle stderr
if (num2 && (num2=read(stdErr.istream(), buf, sizeof(buf)))>0)
_err += std::string(buf, num2);
else if (num2==-1 && (errno!=EINTR&&errno!=EAGAIN))
throw ExecutionFailedExc("readin stderr", *_cmd);
} catch (...) {
if (exc) throw;
_success = false;
return *this;
}
} else { // child
21 years ago
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 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 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 && (errno!=EINTR&&errno!=EAGAIN))
throw ExecutionFailedExc("writing stdin", *_cmd);
// check and handle stdout
if (num1 && (num1=read(stdOut.istream(), buf, sizeof(buf)))>0)
_res += std::string(buf, num1);
else if (num1==-1 && (errno!=EINTR&&errno!=EAGAIN))
throw ExecutionFailedExc("readin stdout", *_cmd);
// check and handle stderr
if (num2 && (num2=read(stdErr.istream(), buf, sizeof(buf)))>0)
_err += std::string(buf, num2);
else if (num2==-1 && (errno!=EINTR&&errno!=EAGAIN))
throw ExecutionFailedExc("readin stderr", *_cmd);
} catch (...) {
if (exc) throw;
_success = false;
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;
}