NAME
look - find lines in a sorted list

SYNOPSIS
look [ -df ] string [ file ]

DESCRIPTION
Look consults a sorted file and prints all lines that begin with
string. It uses binary search.

The options d and f affect comparisons as in sort(1):

d ‘Dictionary’ order: only letters, digits, tabs and blanks
participate in comparisons.

f Fold. Upper case letters compare equal to lower case.

Return codes: 0 -> success, 1 -> failure, 2 -> bad file

If no file is specified, /usr/dict/words is assumed with collating
sequence -df.

FILES
/usr/dict/words