About

mruby-kernel-process provides an object-oriented interface around processes on FreeBSD systems. Unlike shelling out to ps(1), this library reads process information through FreeBSD's native libutil(3) interfaces – in particular kinfo_getproc(3) and kinfo_getallproc(3).

Why "Kernel" ?

The two functions that we use are implemented as easy-to-use wrappers around sysctl(3) – which is used to query kernel state, including information about active processes, hence the name "Kernel Process". It also avoids confusion and conflict with mruby-process.

Quick start

Kernel::Process

The Kernel::Process singleton class is enumerable. It provides access to all processes that are visible to a user. We can use the each method to iterate over processes, we can use the select method to filter, and we can use the map method to trasform:

##
# Iterate all
Kernel::Process.each do |process|
  print "pid=#{process.pid}",
        "ppid=#{process.ppid}",
        "uid=#{process.uid}",
        "\n\n"
end

##
# Select root processes
Kernel::Process.select do |process|
  process.uid == 0
end

##
# Transform processes
parents = Kernel::Process.map(&:ppid)

Kernel::Process.self

The Kernel::Process.self method returns an instance of Kernel::Process that represents the current process:

this = Process.self
print "pid = ", this.pid, "\n"

Kernel::Process.find

The Kernel::Process.find method can find a process by ID, and returns an instance of Kernel::Process or raises an error when a process by the given ID cannot be found:

process = Kernel::Process.find(12345)
print "pid " , "\t", process.pid  , "\n"  # => process ID
print "ppid ", "\t", process.ppid , "\n"  # => parent process ID
print "uid " , "\t", process.uid  , "\n"  # => effective user id
print "ruid ", "\t", process.ruid , "\n"  # => real user id
print "svuid", "\t", process.svuid, "\n"  # => saved user id

Build

MRuby::Build.new("app") do |conf|
  conf.toolchain
  conf.gembox "default"
  conf.gem github: "0x1eef/mruby-kernel-process", branch: "main"
end

License

BSD Zero Clause
See LICENSE