Adam Kennedy > Process > Process::Launcher

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NAME ^

Process::Launcher - Execute Process objects from the command line

SYNOPSIS ^

  # Create from passed params and run
  perl -MProcess::Launcher -e run MyProcessClass param value
  
  # Create from STDIN params and run
  perl -MProcess::Launcher -e run3 MyProcessClass
  
  # Thaw via Storable from STDIN, and freeze back after to STDOUT
  perl -MProcess::Launcher -e storable MyProcessClass
  
  # Requires Process::YAML to be installed:
  # Thaw via YAML::Syck from STDIN, and freeze back after to STDOUT
  perl -MProcess::Launcher -e yaml MyProcessClass

DESCRIPTION ^

The Process::Launcher module provides a mechanism for launching and running a Process-compatible object from the command line, and returning the results.

Example Use Cases

Most use cases involve isolation. By having a Process object run inside its own interpreter, it is then free do things such as loading in vast amounts of data and modules without bloating out the main process.

It could provide a novel way of giving Out Of Memory (OOM) protection to your Perl process, because when the operating system's OOM-killer takes out the large (or runaway) process, the main program is left intact.

It provides a way to run some piece of code in a different Perl environment than your own. This could mean a different Perl version, or running something with tainting on without needing the main process to have tainting.

FUNCTIONS ^

All functions are imported into the callers by default.

run

The run function creates an object based on the arguments passed to the program on the command line.

The first param is take as the Process class and loaded, and the rest of the params are passed directly to the constructor.

Note that this does mean you can't pass anything more complex than simple string pairs. If you need something more complex, try the storable function below.

Prints one line of output at the end of the process run.

  # Prints the following if the process completed correctly
  OK
  
  # Prints the following if the process does not complete
  FAIL - reason

run3

The run3 function is similar to the run function but assumes you are launching the process via something that makes it easy to pass in params via STDIN, such as IPC::Run3 (recommended)

It takes a single param of the Process class.

It then readsa series of key-value pairs from STDIN in the form

  param1=value
  param2=value

At the end of the input, the key/value pairs are passed to the constructor, and from there the function behaves identically to run above, including output.

serialized

The serialized function is more robust and thorough again.

It takes the name of a Process::Serializable subclass as its parameter, reads data in from STDIN, then calls the deserialize method for the class to get the Process object.

This object has prepare and then run called on it.

The same OK or FAIL line will be written as above, but after that first line, the completed object will be frozen back out via serialize and written to STDOUT as well.

The intent is that you create your object of the Process::Serializable subcless in your main interpreter thread, then hand it off to another Perl instance for execution, and then optionally return it to handle the results.

SUPPORT ^

Bugs should be reported via the CPAN bug tracker at

http://rt.cpan.org/NoAuth/ReportBug.html?Queue=Process

For other issues, contact the author.

AUTHOR ^

Adam Kennedy <adamk@cpan.org>

SEE ALSO ^

http://ali.as/

COPYRIGHT ^

Copyright 2006 - 2011 Adam Kennedy.

This program is free software; you can redistribute it and/or modify it under the same terms as Perl itself.

The full text of the license can be found in the LICENSE file included with this module.

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