Dump input stream at a given path

dump.bash

# This function dumps the input stream to the path given as parameter.
# If PATH gets unlinked by another (cooperative) process, it creates a new file at PATH and continues dump
# Provide a lockfile as the 2nd positional parameter. This is needed so that another process doesn't remove PATH
# when it is being written to.

stream_dump(){
  declare -x path="${1}"
  local lock="${2}"
  local timeout="1" # Interval for polling $path
  declare -x line
  IFS=
  while :; do
    read -r -d '' -t "${timeout}" line
    flock "${lock}" -c 'echo -n "${line}" >> "${path}"'
  done
}

# Test:
# Source this function with: . ./dump.bash
# Keep typing input stream after: stream_dump my_dump.txt write.lock
# In another terminal run: tail --quiet -F my_dump.txt 2>/dev/null