bash script to kill a process if no output for 60 seconds (feat. ChatGPT)

timeout-wrapper.sh

#!/bin/bash

# This script runs a command and kills it if there is no output for a certain time

# Define the command to run and the output file
COMMAND="lmp_mpi -in input.lmp"
OUTPUT_FILE="lammps.log"

# Define the timeout value in seconds
TIMEOUT=60

# Run the command and redirect the output to the output file
$COMMAND > $OUTPUT_FILE &

# Get the process ID of the command
PID=$!

# Loop until the process is killed or exits normally
while kill -0 $PID 2>/dev/null; do

  # Wait for the output file to be modified or timeout
  inotifywait -e modify -t $TIMEOUT $OUTPUT_FILE >/dev/null 2>&1

  # Check the exit status of inotifywait
  STATUS=$?

  # If the status is 2, it means no change occurred within the timeout
  if [ $STATUS -eq 2 ]; then

    # Kill the process with SIGTERM
    kill -TERM $PID

    # Print a message to stderr
    echo "Process killed due to no output for $TIMEOUT seconds" >&2

    # Break the loop
    break
  fi
done

# Wait for the process to terminate and get its exit code
wait $PID
EXIT_CODE=$?

# Print a message to stderr if the process exited abnormally
if [ $EXIT_CODE -ne 0 ]; then
  echo "Process exited with code $EXIT_CODE" >&2
fi