Linux Cheat Sheet

Sheel and Bash

Replace all file in a folder with another file. Works recursively and source and target both follow regex

find <folder where you want to fiind> -name "*.pem" -exec cp file.pem '{}' \;

Delete all files in a folder with an extension / pattern

find . -name "*.tf-e" -type f #find all file

Use with precaution

find . -name "*.txt-e" -type f -delete

Find and replace a word in all files in a folder

Only on MacOS if find command doesn't work

export LC_CTYPE=C 
export LANG=C

find ./ -type f -exec sed -i '' -e 's/Hello/Linux/g' {} \;

Find a folder and copy a folder inside the folder

find . -type d -name "04-*" -exec cp -r <folder path> '{}' \;

For loop with String Numbers

for ((i = "1"; i <= "6"; i++)); do 
   echo "$i"
done

For loop with Numbers

for ((i = 1; i <= 6; i++)); do 
   echo "$i"
done

Generate SHA512 Password and set password using HASH

PASSWORD='password'
LINUX_USER='root'
HASH=$(openssl passwd -1 $PASSWORD)
echo $HASH
usermod -p "$HASH" $LINUX_USER

Get list of larget files in a folder recursively

find . -type f -exec du -h {} + | sort -rh | head -n 10