grep command is used to locate a pattern in a file. By default it prints the line that contains the pattern.
Syntax
grep [option] pattern [file]
grep must have a pattern.
Option for grep
-c, --count
prints a count of matching lines for each input file instead of the normal output.
-E, --extended - regexp
interprets the attern as extended regula expression
-e pattern, --regexp=pattern
uses pattern
-F, --fixed-strings
interprets the pattern as a list of fixed strings
-f file, --file=file
obtains the search pattern from file.
--help
brief help
-r, --recursive
reads all files under directory
Tags: Linux