look - find lines in a sorted list look [ -dfnix ] [ -r " endkey" ] [ -t c ] [ string ] [ file ] Look consults a sorted file and prints all lines that begin with string . It uses binary search.

The following options are recognised:

-i Interactive. There is no string argument; instead look takes lines from the standard input as strings to be looked up.

-x Exact. Print only lines of the file whose key matches string exactly.

-d `Directory' order: only letters, digits, tabs and blanks participate in comparisons.

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

-n Numeric comparison with initial string of digits, optional minus sign, and optional decimal point.

-r " endkey" Limit the range of matching values, to include the word endkey but no larger values.

-t [ \f2c\f1 ] Character c terminates the sort key in the file . By default, tab terminates the key. If c is missing the entire line comprises the key.

If no file is specified, /lib/words is assumed, with collating sequence df .

/lib/words /appl/cmd/look.b sort (1), grep (1) The exit status is "not found" if no match is found, and "no dictionary" if file or the default dictionary cannot be opened.