linjam/JuceLibraryCode/modules/juce_core/threads/juce_ChildProcess.h

/*
  ==============================================================================

   This file is part of the juce_core module of the JUCE library.
   Copyright (c) 2013 - Raw Material Software Ltd.

   Permission to use, copy, modify, and/or distribute this software for any purpose with
   or without fee is hereby granted, provided that the above copyright notice and this
   permission notice appear in all copies.

   THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES WITH REGARD
   TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS. IN
   NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL
   DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER
   IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN
   CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.

   ------------------------------------------------------------------------------

   NOTE! This permissive ISC license applies ONLY to files within the juce_core module!
   All other JUCE modules are covered by a dual GPL/commercial license, so if you are
   using any other modules, be sure to check that you also comply with their license.

   For more details, visit www.juce.com

  ==============================================================================
*/

#ifndef JUCE_CHILDPROCESS_H_INCLUDED
#define JUCE_CHILDPROCESS_H_INCLUDED


//==============================================================================
/**
    Launches and monitors a child process.

    This class lets you launch an executable, and read its output. You can also
    use it to check whether the child process has finished.
*/
class JUCE_API  ChildProcess
{
public:
    //==============================================================================
    /** Creates a process object.
        To actually launch the process, use start().
    */
    ChildProcess();

    /** Destructor.
        Note that deleting this object won't terminate the child process.
    */
    ~ChildProcess();

    /** These flags are used by the start() methods. */
    enum StreamFlags
    {
        wantStdOut = 1,
        wantStdErr = 2
    };

    /** Attempts to launch a child process command.

        The command should be the name of the executable file, followed by any arguments
        that are required.
        If the process has already been launched, this will launch it again. If a problem
        occurs, the method will return false.
        The streamFlags is a combinations of values to indicate which of the child's output
        streams should be read and returned by readProcessOutput().
    */
    bool start (const String& command, int streamFlags = wantStdOut | wantStdErr);

    /** Attempts to launch a child process command.

        The first argument should be the name of the executable file, followed by any other
        arguments that are needed.
        If the process has already been launched, this will launch it again. If a problem
        occurs, the method will return false.
        The streamFlags is a combinations of values to indicate which of the child's output
        streams should be read and returned by readProcessOutput().
    */
    bool start (const StringArray& arguments, int streamFlags = wantStdOut | wantStdErr);

    /** Returns true if the child process is alive. */
    bool isRunning() const;

    /** Attempts to read some output from the child process.
        This will attempt to read up to the given number of bytes of data from the
        process. It returns the number of bytes that were actually read.
    */
    int readProcessOutput (void* destBuffer, int numBytesToRead);

    /** Blocks until the process has finished, and then returns its complete output
        as a string.
    */
    String readAllProcessOutput();

    /** Blocks until the process is no longer running. */
    bool waitForProcessToFinish (int timeoutMs) const;

    /** If the process has finished, this returns its exit code. */
    uint32 getExitCode() const;

    /** Attempts to kill the child process.
        Returns true if it succeeded. Trying to read from the process after calling this may
        result in undefined behaviour.
    */
    bool kill();

private:
    //==============================================================================
    class ActiveProcess;
    friend struct ContainerDeletePolicy<ActiveProcess>;
    ScopedPointer<ActiveProcess> activeProcess;

    JUCE_DECLARE_NON_COPYABLE_WITH_LEAK_DETECTOR (ChildProcess)
};


#endif   // JUCE_CHILDPROCESS_H_INCLUDED