Function to disown and redirect output for a stopped or background process

fo.sh

fo() {
  # Generate a random file name if no output file is provided
  if [ "$#" -lt 1 ]; then
    OUTPUT_FILE=$(mktemp /tmp/output_XXXXXX.log)
  else
    OUTPUT_FILE="$1"
  fi

  echo "Redirecting output to $OUTPUT_FILE"

  JOB_ID=${2:-1}  # Default job ID to 1 if not provided

  # Check if the job exists
  if ! jobs %$JOB_ID &> /dev/null; then
    echo "Job ID %$JOB_ID does not exist."
    return 1
  fi

  # Move the stopped job to the background
  if ! bg %$JOB_ID &> /dev/null; then
    echo "Failed to move job %$JOB_ID to the background."
    return 1
  fi

  # Disown the job
  if ! disown %$JOB_ID &> /dev/null; then
    echo "Failed to disown job %$JOB_ID."
    return 1
  fi

  # Get the PID of the job
  PID=$(jobs -l %$JOB_ID | awk '{print $2}')

  if [ -z "$PID" ]; then
    echo "Failed to get PID for job ID %$JOB_ID."
    return 1
  fi

  # Build the gdb commands as a string
  GDB_COMMANDS=$(cat <<EOF
p (int)close(1)
p (int)open("$OUTPUT_FILE", 0101, 0666)
p (int)close(2)
p (int)dup(1)
detach
quit
EOF
  )

  # Check if gdb is available
  if ! command -v gdb &> /dev/null; then
    echo "gdb could not be found. Please install gdb to use this function."
    return 1
  fi

  # Run gdb with process substitution
  if ! echo "$GDB_COMMANDS" | gdb -p "$PID" &> /dev/null; then
    echo "Failed to redirect output."
    return 1
  fi

  echo "Output successfully redirected to $OUTPUT_FILE"
}