Linux – Can bash variables be multiline?

I wrote a script to list path entries and filter them by keywords. I managed to get it to work, but I had to write the list in a temporary file because I couldn’t store it in memory while keeping line breaks. Is there a better/more suitable solution?

 #! /bin/bash
tr ':' '\n' <<< $PATH > tmp
if (( $# > 0 )); then
  for W
  do
    grep $W < tmp
  done
else
  cat tmp
fi
rm tmp

Yes, variables can contain line breaks. You need to reference the variable when you use it. Your script can be written as:

tmp=$(tr ':' '\n' <<< $PATH)
if (( $# > 0 )); then
  for W; do
    grep $W <<< "$tmp"
  done
else
  echo "$tmp"
fi