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"

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#Originally made by Isaac Cook https://gist.github.com/icook/5400173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

#
# Austin Leath
# checks for /Desktop symlink. Creates the symlink if it doesnt already exist
#

#Fetch the target user if desired, otherwise use the currently logged in user.
if [ "$4" != "" ]; then
    TARGET_USER=$4
else
    TARGET_USER=$3
fi

if [ "$5" != "" ]; then
    DIRECTORY_NAME=$5
else
    TARGET_USER="$3 Desktop"
fi

# Functions

CHECK_SYMLINK() {
    if test -f "/Desktop"; then
        echo "/Desktop exists"
    else
        echo "/Desktop does not exist"
    fi
}


CHECK_SYNTHETIC_CONF() {
    if test -f "/etc/synthetic.conf"; then
        echo "/etc/synthetic.conf exists"
    else
        echo "/etc/synthetic.conf does not exist"
    fi
}

CREATE_SYMLINK() {
    if [[ $(CHECK_SYNTHETIC_CONF) != "/etc/synthetic.conf exists" ]]; then
        echo "/etc/synthetic.conf does not exist. creating.."
        touch /etc/synthetic.conf
        chown -R root:wheel /etc/synthetic.conf
    fi

    if grep -q "$DIRECTORY_NAME" /etc/synthetic.conf; then
        echo "$DIRECTORY_NAME already exists"
        exit 1
    else
        echo "$DIRECTORY_NAME\t/Users/$TARGET_USER/Desktop" >> /etc/synthetic.conf
    fi
    
    echo "/Desktop symbolic link created"
}

if [[ $(CHECK_SYMLINK) != "/Desktop exists" ]]; then
    CREATE_SYMLINK
fi

exit 0

#!/bin/sh

BAT_LOW=15
BAT_CRITICAL=5

if [ "$1" = "--help" ]
then
    printf "
    Usage:
    \tbattery_check.sh warning%% hibernate%%

    Description:
    \tA script for notifying the user via dunst and logging when
    \tthe battery is low and the system is going to hibernate.
    \tCan be supplied arguments for the battery low warning and
    \thibernation percentage thresholds as the first and second arguments.

    \t Default behavior is to warn at 15% and hibernate at 5%."
    exit
fi

if [[ -n "$1" && -n "$2" && $1 -gt $2 ]]
then
    BAT_LOW=$1
    BAT_CRITICAL=$2
fi

acpi -b | awk -F'[,:%]' '{print $2, $3}' | {

    read -r status capacity
    echo Low threshold: $BAT_LOW, Hibernate threshold: $BAT_CRITICAL
    echo Status: $status, Capacity: $capacity

    if [ "$status" = Discharging -a "$capacity" -le $BAT_CRITICAL ]; then
        echo Battery critical threshold.
        dunstify -u critical "Critical battery threshold, hibernating..."
        logger "Critical battery threshold, hibernating..."
        sleep .5
        systemctl hibernate
        exit
    fi

    if [ "$status" = Discharging -a "$capacity" -le $BAT_LOW ]; then
        echo Battery low threshold.
        dunstify -u critical 'Battery low! System will hibernate at 5%.'
        logger 'Battery low! System will hibernate at 5%.'
        sleep .5
        light -S 15
        exit
    fi
}

CLIENT_VPN_ID="cvpn-endpoint-xxxxxxxxxxxx"

for region in $(aws ec2 describe-regions --query "Regions[].RegionName" --output text); do
    echo "Searching in region: $region"
    aws ec2 describe-client-vpn-endpoints --region $region --query "ClientVpnEndpoints[?ClientVpnEndpointId=='$CLIENT_VPN_ID']" --output table
done

# Update all npm packages under the scope defined by the PREFIX variable ("foo").
PREFIX="foo"; npm ls | grep "$PREFIX" | awk -F/ '{print $NF}' | sed 's/@.*//' | xargs -I package npm update @"$PREFIX"/package