Table Of Contents :
What is GREP ?
The grep filter searches a file for a particular pattern of characters, and displays all lines that contain that pattern. GREP stands for Global regular expression print .
To see the help menu of GREP you have to use this command -:
grep --help 
GREP syntax
So, this is the basic syntax of grep. Firstly grep then followed by an option then pattern of the file or text to match then the file name.
grep [OPTION...] PATTERNS [FILE...] grep [OPTION...] -e PATTERNS... [FILE...] grep [OPTION...] -f PATTERN_FILE ... [FILE...]
GREP OPTIONS
Wildcards
Regular expressions
BRE, ERE & PCRE PCRE
Quantifiers
Posix
Position
