The "look" command is a Linux utility that is used to search for lines in a sorted text file that match a specified prefix.
help
Usage:
look [options] <string> [<file>...]
Display lines beginning with a specified string.
Options:
-a, --alternative use the alternative dictionary
-d, --alphanum compare only blanks and alphanumeric characters
-f, --ignore-case ignore case differences when comparing
-t, --terminate <char> define the string-termination character
-h, --help display this help
-V, --version display version
For more details see look(1).