ronvanderheijden / bash

SSH

ssh-keygen -t rsa -P "" -f /home/client/.ssh/id_rsa -q

chmod 700 /home/client/.ssh/
chmod 600 /home/client/.ssh/id_rsa
chmod 644 /home/client/.ssh/id_rsa.pub

chmod 600 /home/server/.ssh/authorized_keys # cp id_rsa.pub authorized_keys

SCRIPTING

shift

arg1=$1; shift
arg2=$1

statements

[[ -z "$1" ]] && echo 'Missing parameter' && exit 1

if [ ! -d "source" ]; then
  echo 'Directory not found'
  exit 1
fi

cases

case "$1" in
    # i rest my case
    version) echo "1.0.0" ;;
    *) echo "Command not found!" && exit 1 ;;
esac

read

read -p "Question? " answer

ask () {
    read -p "$1 ($2)? " answer
    [[ -z "$answer" ]] && answer=$2
    echo $answer
}
ask "What is your name" "Ron"

SEARCH

grep - search

# grep -e search_pattern inputfile
echo abc123 | grep -Po "([0-9]{2})"
# result: 12

sed - search / replace

# sed s/search_pattern/replace_pattern/ inputfile
echo 121 | sed s/1/8/g
# result: 828

awk - search / execute

# awk search_pattern {actions} inputfile
echo 121 | awk '{print $1*4}'
# result: 484

SNIPPETS

See https://github.com/ronvanderheijden/bash/tree/master/snippets