IFS

IFS (Internal Field Separator) is a special environment variable that defines the delimiter used for word splitting in Unix shells. The default value of IFS is a space, tab, and newline. The three characters serve as delimiters. More information: https://www.gnu.org/software/bash/manual/html_node/Word-Splitting.html.

echo "$IFS"

IFS=":"

IFS=$' \t\n'

(IFS=":"; echo "one:two:three")