Linux cli snippets

Linux command line snippets

Get website SSL certificate details using CLI

$ echo | openssl s_client -showcerts -servername sendfileto.net -connect sendfileto.net:443 2>/dev/null | openssl x509 -inform pem -noout -text

Temporary stop bash history

Turn off:

$ set +o history

Turn on:

$ set -o history

Alternative is to add HISTCONTROL="ignorespace" into .bashrc file and all things written with space in front wont be recorded in history

Check ssl expiry date on file from cli

# openssl x509 -noout -dates -in /path/to/cert.crt

Check ssl expiry date from linux cli

# echo | openssl s_client -showcerts -servername devopsnotebook.com -connect devopsnotebook.com:443 2>/dev/null | openssl x509 -inform pem -noout -text |grep 'Not After'

Start all vm's with autostart set with virsh

# for i in $(virsh list --name --autostart); do virsh start $i; done

Sort files by size with ls

# ls -l -S | sort -k 5 -n

Change different permissions to files and folders in one run recursively

# find /path/to/dir -type f -exec chmod 664 {} + -o -type d -exec chmod 775 {} +

Search and replace string in all files recursively in given folder

# find ./ -type f -exec sed -i -e 's/tomato/potato/g' {} \;

Destroy all partitions table and data on drive

# sgdisk --zap-all /dev/nvme0n1

Push dns changes to secondary

# rndc retransfer domain.com

Delete 5 lines after a pattern with sed (including the line with the pattern)

# sed -e '/pattern/,+5d' file.txt

Delete 5 lines after a pattern with sed (excluding the line with the pattern)

# sed -e '/pattern/{n;N;N;N;N;d}' file.txt