Hi all,

I have a selection of files that contain several commands that write to a file and are started as background processes similar to below.

command_to_run_simulator -simulator_arguments > log_file 2>&1 &
command_to_run_simulator -simulator_arguments > log_file 2>&1 &
command_to_run_simulator -simulator_arguments > log_file 2>&1 &

#!/bin/sh

while read line
do
 $line
  # command_to_run_simulator -simulator_arguments > log_file 2>&1 &
  echo $!
done < $1

I can't reproduce your error message but you need to use "eval" to execute a command you have generated after the script started running.

eval "${line}"

Thanks for that methyl, that solved my problem.

I'm still interested in the mechanics of what was going on/going wrong if anyone can explain.