oct-process.cc

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////////////////////////////////////////////////////////////////////////
//
// Copyright (C) 2019-2021 The Octave Project Developers
//
// See the file COPYRIGHT.md in the top-level directory of this
// distribution or <https://octave.org/copyright/>.
//
// This file is part of Octave.
//
// Octave is free software: you can redistribute it and/or modify it
// under the terms of the GNU General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
//
// Octave is distributed in the hope that it will be useful, but
// WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
// GNU General Public License for more details.
//
// You should have received a copy of the GNU General Public License
// along with Octave; see the file COPYING.  If not, see
// <https://www.gnu.org/licenses/>.
//
////////////////////////////////////////////////////////////////////////
 
#include <iostream>
#include <sstream>
 
#include "oct-process.h"
#include "procstream.h"
#include "sysdep.h"
#include "oct-syscalls.h"
 
namespace octave
{
  OCTINTERP_API
  process_execution_result
  process_execution_result::of_success (int exit_status,
                                        const std::string& stdout_output)
  {
    return process_execution_result (0, exit_status, stdout_output, "");
  }
 
  OCTINTERP_API
  process_execution_result
  process_execution_result::of_error (int status, const std::string& err_msg)
  {
    return process_execution_result (status, -1, "", err_msg);
  }
 
  // Execute a shell command, returning results as a C++ object
  OCTINTERP_API
  process_execution_result
  run_command_and_return_output (const std::string& cmd_str)
  {
    iprocstream cmd (cmd_str.c_str ());
 
    if (! cmd)
      {
        std::string msg = "unable to start subprocess for '" + cmd_str + "'";
 
        return process_execution_result::of_error (-1, msg);
      }
 
    std::ostringstream output_buf;
 
    char ch;
 
    for (;;)
      {
        if (cmd.get (ch))
          output_buf.put (ch);
        else
          {
            if (! cmd.eof () && errno == EAGAIN)
              cmd.clear ();
            else
              break;
          }
      }
 
    int cmd_status = cmd.close ();
 
    if (sys::wifexited (cmd_status))
      cmd_status = sys::wexitstatus (cmd_status);
    else
      cmd_status = 127;
 
    return process_execution_result::of_success (cmd_status, output_buf.str ());
  }
}