ifs

View the current $IFS value

$ echo "$IFS"

$ IFS="[:]"

$ IFS=$' \t\n'

$ (IFS="[:]"; echo "[one:two:three]")

No standard syntax; use IFS=chars before shell commands

IFS
    Environment variable; set to characters like '<space><tab>\n' for default splitting

The term ifs does not correspond to any standard executable command in Linux distributions or core utilities. It is commonly confused with IFS, the Internal Field Separator environment variable used in POSIX-compliant shells like Bash, Zsh, and others.

IFS controls the delimiter characters for word splitting during command substitution, read builtins, and expansions. By default, IFS is set to space, tab, and newline (" "). Changing it affects how the shell parses strings into words.

For example:
IFS=',' read -r a b <<< '1,2,3'
sets a='1', b='2', leaving 3 in the reply variable.

To view: echo "$IFS" | cat -v
To reset: unset IFS or IFS=$' '.

If ifs refers to a custom script, package-specific tool (e.g., in embedded systems or third-party software), check local man pages or which ifs. No coreutils, util-linux, or busybox equivalent exists.

Modifying IFS globally affects all subsequent parsing; use local scope (e.g., (IFS=','; ...)) to avoid side effects.
Empty IFS treats entire string as one field.

Loop over CSV: IFS=','; for f in $(cat file.csv); do ...; done
Avoid with while IFS=',' read -r ...; do ...; done < file.

Visualize: printf '%q ' "$IFS" or pipe to cat -A.

Originated in original UNIX Bourne shell (1977); standardized in POSIX.1-2008. Evolved with shell enhancements for better quoting and arrays.

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