ACE_OS：execlp获取结果-标准输出

Question

After several hours of googling I'm still failing to understand how to obtain result from ACE_OS::execlp command. Here I need to obtain not the status itself but the output result. For instance if I call some bash script and it produces its stdout/stderr.

Can anybody help me how to obtain it?

Thank you!

Answer 1

I am afraid this function seems not implemented: according to the github ( https://github.com/DOCGroup/ACE_TAO/blob/master/ACE/ace/OS_NS_unistd.cpp )

and the code :

int
ACE_OS::execlp (const char * /* file */, const char * /* arg0 */, ...)
{
  ACE_OS_TRACE ("ACE_OS::execlp");
  ACE_NOTSUP_RETURN (-1);
  // Need to write this code.
  //  ACE_OSCALL_RETURN (::execvp (file, argv), int, -1);
}

Alternatively you could use the <cstdlib> (if supported by your compiler chain) and a code like :

#include <cstdlib>
#include <fstream>
#include <iostream>

int main()
{
    std::system("ls -l >test.txt"); // execute the UNIX command "ls -l >test.txt"
    std::cout << std::ifstream("test.txt").rdbuf();
}

as seen at http://en.cppreference.com/w/cpp/utility/program/system