Linux Today: Linux News On Internet Time.

Command line made easy: five simple recipes for grep

May 06, 2009, 18:01 (0 Talkback[s])
(Other stories by Ryan Paul)

"The most common and basic scenario of grep usage is a text search. It can be used to find instances of a word or phrase in files and text streams. You can invoke it at the command line by typing the command name, the search query, and the target files in which to search. To find the word "needle" in the haystack.txt file, I use the following command:

$ grep needle haystack.txt

"This will cause grep to display any line from haystack.txt that contains the text "needle". In this example, it's important to note that grep is matching the raw characters and not the word. It will, for example, also show lines that include "needless" and other words that contain "needle". You can instruct grep to search for the query text as a word by using the -w parameter. This will limit the output to lines in which the query text is surrounded on both sides by any combination of spaces, punctuation, or line breaks."

Complete Story

Related Stories: