Basics

Brace expansion

echo {1..10} # 1 2 3 4 5 6 7 8 9 10
echo {1..10..3} # 1 4 7 10
touch {file1, file2, file3}; ls # file1 file2 file3

touch file_{1..10}; ls # file1 file2 file3 ... file10

Padding with zero

touch file_{01..100}; ls # file01 file02 .. file100

ls -l | wc -l  # wordcount all the files

more is cat with pagination.

ls -l | more

Redirect

use >:

• 1 is stdout
• 2 is sterr
• & is stdout and sterr

Search

grep

Enable color

grep --color=auto jorge auth.log

To enable it all the time use: export GREP_OPTIONS='--color=auto'

Exclude directory

grep -R --exclude-dir=node_modules 'some pattern' /path/to/search

Include lines after the find

grep -A2 textToSearch jsx/

-A2 will return the two lines after. -B2 will return the two previous lines. -C2 will return two lines before and after.

awk Command

This will print only the 12th word on every sentence:

grep -i break-in auth.log | awk {'print $12'}

Another useful command: sed