The Three Musketeers of Linux

Accompanying notes:

grep filtering

SED fetch line
awk fetching columns

1. grep

grep Lookup

grep-v Filter Finder  

Syntax: grep content parameter line number file
-a displays matching rows and preceding rows
grep 30-a 1.txt Display 30 front 10 lines
-B displays matching rows and subsequent rows
grep 30-b 1.txt
-C Displays matching rows and displays the number of rows before and after matching
grep 30-c 1.txt

-I is case insensitive
-E Filter Multiple strings
-O output exact matching characters instead of the default entire line

2. Sed

SED replacement

Sed-i ' s# original character # destination character #g ' file name

Sed-i ' S#boy#girl#g ' test.txt

SED output

Sed-i '/character/p ' Find matching line output

Sed-i '/character/d ' Delete matching line output

3. awk

awk ' {print $n} ' output column n represents a column

The Three Musketeers of Linux