look looks for entries in a list which contain a given string as prefix
look [-bdf] [-t termchar] string [file...]
-b Use binary search. Requires input to be sorted.
-d Use alphanumerics only, and dictionary sorting
-f ignore case
-t stop comparisons on the given terminator character.
The command is affected by environment variables LANG, LC_ALL, and LC_CTYPE as described in the environ(7) man page.
Most (all?) Linux distributions incorporate this from the [util-linux] project