Class: Runfile::ExecHandler

Inherits:
Object
  • Object
show all
Includes:
Singleton
Defined in:
lib/runfile/exec.rb

Overview

This class provides methods for easily and politely run shell commands through a Runfile action. It is mainly a convenient wrapper around ‘system` and `exec` and it also adds functions for running background tasks with ease.

Instance Method Summary collapse

Instance Method Details

#after_run(&block) ⇒ Object

Set a block to be called after each run



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# File 'lib/runfile/exec.rb', line 61

def after_run(&block)
  @after_run_block = block
end

#before_run(&block) ⇒ Object

Set a block to be called before each run



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# File 'lib/runfile/exec.rb', line 56

def before_run(&block)
  @before_run_block = block
end

#run(cmd) ⇒ Object

Run a command, wait until it is done and continue



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# File 'lib/runfile/exec.rb', line 13

def run(cmd)
  cmd = @before_run_block.call(cmd) if @before_run_block
  return false unless cmd
  say "!txtgrn!> #{cmd}" unless Runfile.quiet
  system cmd
  @after_run_block.call(cmd) if @after_run_block
end

#run!(cmd) ⇒ Object

Run a command, wait until it is done, then exit



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# File 'lib/runfile/exec.rb', line 22

def run!(cmd)
  cmd = @before_run_block.call(cmd) if @before_run_block
  return false unless cmd
  say "!txtgrn!> #{cmd}" unless Runfile.quiet
  exec cmd
end

#run_bg(cmd, pid: nil, log: '/dev/null') ⇒ Object

Run a command in the background, optionally log to a log file and save the process ID in a pid file



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# File 'lib/runfile/exec.rb', line 31

def run_bg(cmd, pid: nil, log: '/dev/null')
  cmd = @before_run_block.call(cmd) if @before_run_block
  return false unless cmd
  full_cmd = "exec #{cmd} >#{log} 2>&1"
  say "!txtgrn!> #{full_cmd}" unless Runfile.quiet
  process = IO.popen "exec #{cmd} >#{log} 2>&1"
  File.write pidfile(pid), process.pid if pid
  @after_run_block.call(cmd) if @after_run_block
  return process.pid
end

#stop_bg(pid) ⇒ Object

Stop a command started with ‘run_bg’. Provide the name of he pid file you used in ‘run_bg’



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# File 'lib/runfile/exec.rb', line 44

def stop_bg(pid)
  file = pidfile(pid)
  if File.exist? file
    pid = File.read file
    File.delete file
    run "kill -s TERM #{pid}"
  else
    say "!txtred!PID file not found." unless Runfile.quiet
  end
end