Cheat Sheet

Bash:

echo $? - exit status of last command (0 no error)

' - Single quote removes meaning special meaning of special character.

find /qwe -type f -iname *.js -exec cp --parents -t /tmp/ {} + -- find all js files and copy with parent directory

ystemctl set-default graphical.target (ls -l /lib/systemd/system/runlevel*) -- set runlevel

echo <password> | sudo -S

for i in t@01 st@02 ba@sta03;do ssh -o RequestTTY=true $i "sudo -l";done -- allow tty present

VIM:

:r! sed -n '16,812 p' < input_file.txt -- copy line range from input_file

:1,10d -- delete line from 1 to 10

:se nu -- show line numbers

Apache:

Redirection in Apache (By default, the Redirect directive establishes a 302, or temporary, redirect.):

URL:https://www.digitalocean.com/community/tutorials/how-to-create-temporary-and-permanent-redirects-with-apache-and-nginx

<VirtualHost *:80>

ServerName www.domain1.com

Redirect 301 /oldlocation http://www.domain2.com/newlocation

</VirtualHost>

ServerTokens Prod -- hides Apache version

Logrotate:

vi /etc/logrotate.d/

IPTABLES:

iptables -A INPUT -p tcp -m tcp --dport 5000 -j DROP -- discard incoming traffic

iptables -A INPUT -p tcp -m tcp --dport 8094 -j ACCEPT -- allow incoming traffic

iptables -D INPUT -p tcp -m tcp --dport 5000 -j DROP -- Delete rule

iptables -I INPUT -p tcp ! -s yourIPaddress --dport 22 -j DROP -- discard incoming traffic for posrt 22 except yourIPaddress

iptables-save >/etc/sysconfig/iptables -- save rules

GIT:

git init -- creates .git folder

Files are untracked when first created

git add -- to start tracking (stage all files and changes in the current folder)

git diff --staged show changes on added files