How do I split a string on a delimiter in Bash?

Question

I have this string stored in a variable:

IN=\"bla@some.com;john@home.com\"

Now I would like to split the strings by ; delimite

Answer 1

Two bourne-ish alternatives where neither require bash arrays:

Case 1: Keep it nice and simple: Use a NewLine as the Record-Separator... eg.

IN="bla@some.com
john@home.com"

while read i; do
  # process "$i" ... eg.
    echo "[email:$i]"
done <<< "$IN"

Note: in this first case no sub-process is forked to assist with list manipulation.

Idea: Maybe it is worth using NL extensively internally, and only converting to a different RS when generating the final result externally.

Case 2: Using a ";" as a record separator... eg.

NL="
" IRS=";" ORS=";"

conv_IRS() {
  exec tr "$1" "$NL"
}

conv_ORS() {
  exec tr "$NL" "$1"
}

IN="bla@some.com;john@home.com"
IN="$(conv_IRS ";" <<< "$IN")"

while read i; do
  # process "$i" ... eg.
    echo -n "[email:$i]$ORS"
done <<< "$IN"

In both cases a sub-list can be composed within the loop is persistent after the loop has completed. This is useful when manipulating lists in memory, instead storing lists in files. {p.s. keep calm and carry on B-) }