look—Display lines beginning with a given string
look [–dfa] [–t termchar] string [file]
The look utility displays any lines in file that contain string as a prefix. As look performs a binary search, the lines in file must be sorted.
If file is not specified, the file /usr/dict/words is used, only alphanumeric characters are compared, and the case of alphabetic characters is ignored.
|–d||Dictionary character set and order; that is, only alphanumeric characters are compared.|
|–f||Ignore the case of alphabetic characters.|
|-a||Use the alternate dictionary /usr/dict/web2.|
|–t||Specify a string termination character; that is, only the characters in string up to and including the first occurrence of termchar are compared.|
The look utility exits 0 if one or more lines were found and displayed, 1 if no lines were found, and >1 if an error occurred.