| .TH LOOK 1 |
| .SH NAME |
| look \- find lines in a sorted list |
| .SH SYNOPSIS |
| .B look |
| [ |
| .BI -dfnixt c |
| ] |
| [ |
| .I string |
| ] |
| [ |
| .I file |
| ] |
| .SH DESCRIPTION |
| .I Look |
| consults a sorted |
| .I file |
| and prints all lines that begin with |
| .IR string . |
| It uses binary search. |
| .PP |
| The following options are recognized. |
| Options |
| .B dfnt |
| affect comparisons as in |
| .IR sort (1). |
| .TP |
| .B -i |
| Interactive. |
| There is no |
| .I string |
| argument; instead |
| .I look |
| takes lines from the standard input as strings to be looked up. |
| .TP |
| .B -x |
| Exact. |
| Print only lines of the file whose key matches |
| .I string |
| exactly. |
| .TP |
| .B -d |
| `Directory' order: |
| only letters, digits, |
| tabs and blanks participate in comparisons. |
| .TP |
| .B -f |
| Fold. |
| Upper case letters compare equal to lower case. |
| .TP |
| .B -n |
| Numeric comparison with initial string of digits, optional minus sign, |
| and optional decimal point. |
| .TP |
| .BR -t [ \f2c\f1 ] |
| Character |
| .I c |
| terminates the sort key in the |
| .IR file . |
| By default, tab terminates the key. If |
| .I c |
| is missing the entire line comprises the key. |
| .PP |
| If no |
| .I file |
| is specified, |
| .B /lib/words |
| is assumed, with collating sequence |
| .BR df . |
| .SH FILES |
| .B /lib/words |
| .SH SOURCE |
| .B \*9/src/cmd/look.c |
| .SH "SEE ALSO" |
| .IR sort (1), |
| .IR grep (1) |
| .SH DIAGNOSTICS |
| The exit status is |
| .RB `` "not found" '' |
| if no match is found, and |
| .RB `` "no dictionary" '' |
| if |
| .I file |
| or the default dictionary cannot be opened. |
