for region in `aws ec2 describe-regions --output text | cut -f4`
do
     echo -e "\nListing Instances in region:'$region'..."
     aws ec2 describe-instances --query 'Reservations[*].Instances[*].{Instance:InstanceId,Subnet:SubnetId}' --region $region
done
#This script is to be used with any AWS CLI configured environment, it will list any EC2 instances and their associated subnet network ID's in JSON format

touch /tmp/login1.txt /tmp/login2.txt
while [ true ]
do
	who | gawk '{ print $1 }' > /tmp/login2.txt
	comm -13 /tmp/login1.txt /tmp/login2.txt

	#Just a bit easier to read

	#diff /tmp/login1.txt /tmp/login2.txt
	cat /tmp/login2.txt > /tmp/login1.txt
	sleep 1
done

#!/bin/bash

#Takes all the c and h files in the current directory and prints them

#Yup, it's that easy
for file in *.h *.hpp *.c *.cpp; do

	#If it exists
	if [ -f "$file" ]; then
	echo "//===============$file==============="
	cat $file
	fi
done

#!/bin/bash

#getDependencies.sh by Leif Messinger
	grep -Po '#include\s*"\K.+(?=")' | while read -r line ; do
	echo -n " $line"
	./getDependencies.sh < $line
done

#!/bin/bash

#Originally made by Isaac Cook https://gist.github.com/icook/5400173

#Modified by Leif Messinger

#upload_key.sh [server_ip [server2_ip [...]]]

#To be run locally on a linux computer

if [ -e ~/.ssh/id_rsa.pub ];
then
    echo "SSH Key already exists on local machine"
else
    echo "Generating SSH key on local machine"
    ssh-keygen -t rsa   #generates id_rsa and id_rsa.pub
    chmod -R 700 ~/.ssh #Sets permissions of ssh folder
    ssh-add     #Adds keys (and passwords?) to ssh_agent. (hopefully doesn't require password)
fi

echo "Loading client public key into memory"
pubKey=$(<~/.ssh/id_rsa.pub)

for server
do
    echo "Adding client public key to $server remote server authorized keys"
    #Idiot Isaac Cook didn't know about ssh-copy-id
    #ssh-copy-id even checks if your key already exists
    #In fairness, I didn't either until researching ssh-add
    ssh-copy-id -i ~/.ssh/id_rsa.pub $server        #In theory, this should prompt for a username

    #ssh $server "mkdir -p ~/.ssh;  #Make the folder if not already made
    #       echo \"$pubKey\" >> ~/.ssh/authorized_keys;     #Append your public key to the server's authorized_keys
    #       chmod 700 ~/.ssh && chmod 600 ~/.ssh/authorized_keys"   #Set the correct permissions of those files

    #echo "Adding server public key to local authorized keys"
    #ssh $server "ssh-copy-id -i ~/.ssh/id_rsa.pub \$SSH_CLIENT" #this might need some awk, as $SSH_CLIENT spits out clientip portnumber

    echo "Displaying server public key"
    ssh $server "cat ~/.ssh/id_rsa.pub"

    #Though, he did give me a good idea
    echo "Displaying keys authorized on $server (you can paste them in your authorized_keys file)"
    ssh $server "cat ~/.ssh/authorized_keys"

    #echo "Appending keys authorized on $server to your local authorized_keys"
    #ssh $server "cat ~/.ssh/authorized_keys" >> ~/.ssh/authorized_keys
done
echo "SSH keys schronized successfully!"

name="John"
echo ${name}
echo ${name/J/j}    #=> "john" (substitution)
echo ${name:0:2}    #=> "Jo" (slicing)
echo ${name::2}     #=> "Jo" (slicing)
echo ${name::-1}    #=> "Joh" (slicing)
echo ${name:(-1)}   #=> "n" (slicing from right)
echo ${name:(-2):1} #=> "h" (slicing from right)
echo ${food:-Cake}  #=> $food or "Cake"