cqueues subprocess management

xcq.subprocess is a library to manage subprocesses from a cqueues controller.

Like all other I/O operations in cqueues, reading from, writing to or waiting for a subprocess is asynchronous.

• Can spawn multiple processes and use async I/O to communicate with them
• Lua file handles, cqueues socket, or pipes can be used for stdin/stdout/stderr
• Signals

This library aims to be a simple, just works solution to run and interact with subprocesses. Advanced use cases are not (yet) supported. The priority is to keep a simple to use and clear interface while make it very hard to shoot yourself in the foot.

Status

Alpha: might contain bugs, API not frozen, some features are unfinished:

• Environment is not cleared for now
• Spawning a process as another user still has rough edges, and probably security issues (e.g. no supplementary group management)
• Opened files are not cleared. This shouldn't be a problem with cqueues file descriptors as they are CLOEXEC by default, but this is not the case for raw Lua ones.
• luaposix is big, investigate on lunix for a possible replacement
• Use posix_spawn instead of fork/exec?

Installation

Dependencies

• cqueues
• luaposix for low level system calls

LuaRocks (no stable release yet)

luarocks install https://github.com/jdesgats/xcq.subprocess/raw/master/rockspecs/xcq-subprocess-scm-1.rockspec

Manually

Either put the xcq project somewhere in your Lua path after installing the above dependencies.

API

The API is loosely based on Python's subprocess library but differs when it is possible to take advantage of Lua/cqueues specificities.

See the detailed documentation for details, and the examples directory for more concrete use cases.