swap.sh

#!/bin/sh



# Checking if user is root otherwise throw error
if [ "$(id -u)" -ne 0 ]; then
    echo "This script must be run as root" 
    exit 1
fi


# Availbale Options
if [ ! "$#" -ge 1 ]; then
    echo "Usage: $0 {size}"
    echo "(Default path: /var/lib/swap)"
    printf '%s\n' "$@"

	echo "---------------------------------------"
	echo "Available options:"
	printf '%s\n' "$@"
	echo "size - Size of swap ( Example - 1G,2G or 1024M)"
	echo "path - Path to create a swapfile"
    exit 1
fi

SWAP_SIZE=$1

# Default swap file

SWAP_FILE=/var/lib/swap
if [ ! -z "$2" ]; then
    SWAP_FILE="$2"
fi


# Checking if swap already exists in ./etc/fstab
grep -q "swap" /etc/fstab
if ! grep -q "swap" /etc/fstab; then
	 fallocate -l "$SWAP_SIZE" "$SWAP_FILE"
	 chmod 600 "$SWAP_FILE"
	 mkswap "$SWAP_FILE"
	 swapon "$SWAP_FILE"	
	echo "$SWAP_FILE   none    swap    sw    0   0" |  tee /etc/fstab -a
else
	echo 'swapfile found. No changes made.'
fi

echo '----------------------'
echo 'Checking list of swap'
echo '----------------------'
swapon -s