A running bash script is hung somewhere. Can I find out what line it is on?

Question

E.g. does the bash debugger support attaching to existing processes and examining the current state?

Or can I easily find out by looking at the bash process entries in /

Answer 1

No real solution. But in most cases a script is waiting for a child process to terminate:

ps --ppid  $(pidof yourscript)

You could also setup signal handlers in you shell skript do toggle the printing of commands:

#!/bin/bash

trap "set -x" SIGUSR1
trap "set +x" SIGUSR2

while true; do
    sleep 1
done

Then use

kill -USR1 $(pidof yourscript)
kill -USR2 $(pidof yourscript)