Chapter 9: Filters

Boiled down:

A few select unix commands:

Command	Description
wc	counts the lines, words and characters
wc -l filename	counts the lines
wc -w filename	counts the words
wc -c filename	counts the characters
see the example
head	outputs first ten lines
head -5 filename	outputs first 5 lines
tail -6 filename	outputs last 6 lines
see the example
head -12 filename| tail -6	outputs lines 7 - 12
see the example
cut -f2 filename	cut column 2 out of file. Default delimiter is TAB
cut -d: -f2 filename	cut column 2 out of file using : as delimiter
paste file1e file2	pastes files together via columns
see the example

A few select unix commands:

Command	Description
echo	displays text or values of variables
=	Sets a variable to a value
try=hello echo $try	Don't use spaces to access value, use $
date	displays current date and time
compress somefile	reduces the size of file Creates somefile.Z
uncompress somefile.Z	restores somefile
see the example
sort filename	alphabetically sorts
uniq filename	removes duplicate lines
see the Notes
file filename	type of the file
diff file1 file2	displays the differences in the file < indicates line is from file1 > indicates line is from file2
which command	displays directory of command that will be used (there may be different versions of the same command)
whereis command	displays all places where (the directory) the command is found
apropos command	same as man -k
see the example

All work herein is subject to copyright. Original content to Dr. Deborah Whitfield, text content (Your UNIX/Linux) to Prentice Hall publishing.