This article shows how to determine how much swap space is available on your host to use as memory.
You can simply use the free -m command to see the swap space. The bottom line will contain the information you need.
-bash-4.2# free -m
total used free shared buff/cache available
Mem: 1998 480 409 104 1108 1229
Swap: 1023 37 986
You can also look at the /etc/meminfo file using grep to get the information you need.
-bash-4.2# cat /proc/meminfo | grep Swap
SwapCached: 9592 kB
SwapTotal: 1048572 kB
SwapFree: 1001212 kB