Match any one character ENCLOSED within it
Brackets
Used to SURROUND subexpressions and specify how operators should be applied
Parenthesis
Matches with ONE OR MORE occurrences of a character
+
Match SPECIAL characters
\
Matches with ZERO OR ONE occurrence of a character
?
uses regular expressions
grep
locates files and supports pattern matches
find
basic statistics on text files
wc
displays the number of lines that match
grep -c | –count
takes pattern input from the SPECIFIED FILE
grep -f | –file=file
perform a case insensitive search
grep - i | -ignore
searches directory and sub directory
grep -r | -recursive
extended regular expressions
-extended-regexp | grep -E
ignores case (default is Cap letters first)
sort -f | –ignore-case
sorts by numeric value
sort -n | sort –numeric-sort
writes results to file specified
sort –output=file | sort o
sorts in descending order (default is ascending)
sort –reverse
writes STANDARD INPUT and STANDART OUTPUT to a specified file
<>
writes STANDARD OUTPUT and STANDARD ERROR to a file
&>
