ifs

Set field separator

$ IFS=':' read -ra arr <<< "a:b:c"

$ IFS=$'\n'

$ OLD_IFS="$IFS"; IFS=','; ...; IFS="$OLD_IFS"

$ IFS=$' \t\n'

IFS is a shell variable

IFS (Internal Field Separator) is a shell variable controlling word splitting. It defines characters used to split strings into fields.
The default IFS is space, tab, and newline. Changing IFS affects read, for loops, and word splitting behavior.

IFS

Internal Field Separator variable.

Shell variable, not command. Affects word splitting globally. Restore after use.

IFS is a standard POSIX shell variable, present in all Bourne-compatible shells.

read(1), bash(1), sh(1)