arrays in posix shell is missing

[matu3ba]

Sometimes it can be extremely convenient to have them and having a simple example would help. Also it might help to show some broken behavior of IFS=\n, which can be very surprising.

# https://stackoverflow.com/a/53747300
s='A|B|C|D' # specify your "array" as a string with a sigil between elements
IFS='|'     # specify separator between elements
set -f      # disable glob expansion, so a * doesn't get replaced with a list of files

getNth()  { shift "$(( $1 + 1 ))"; printf '%s\n' "$1"; }
getLast() { getNth "$(( $(length "$@") - 1 ))" "$@"; }
length()  { echo "$#"; }

length $s   # emits 4
getNth 0 $s # emits A
getNth 1 $s # emits B
getLast $s  # emits D

s2='t1 t2 t3 t4'
set -f; IFS=' '      # IFS='\n' appears to be broken
for jar in ${s2}; do
  set +f; unset IFS
  echo "$jar"        # restore globbing and field splitting at all whitespace
done
set +f; unset IFS    # do it again in case $INPUT was empty
echo "done"