34 lines
716 B
Ruby
Executable file
34 lines
716 B
Ruby
Executable file
#!/usr/bin/env ruby
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# daemon_with_pidfile
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#
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# Daemonize, write a pidfile, and exec the remainder of the command line.
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def main(pidfile, cmd)
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if middle_pid = Process.fork
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# outer process
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# Do not exit the outer process before the middle process finishes
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Process.waitpid(middle_pid)
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exit $?.exitstatus
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end
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if final_pid = Process.fork
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# middle process
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open(pidfile, 'w') { |f| f.puts final_pid }
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exit
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end
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# Standard daemon things: become session leader, ignore SIGHUP, close stdin.
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Signal.trap("HUP", "IGNORE")
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Process.setsid
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IO.new(0).close
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exec(*cmd)
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end
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if ARGV.count < 2
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abort "Usage: #$0 pidfile command [args...]"
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end
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pidfile = ARGV.shift
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main(pidfile, ARGV)
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