# Using WebAssembly from Bash
## Getting started and simple example
First up you'll want to start a new module:
```text
$ mkdir -p gcd-bash
$ cd gcd-bash
$ touch gcd.wat gcd.sh
```
Next, copy this example WebAssembly text module into your project. It exports a function for calculating the greatest common denominator of two numbers.
## `gcd.wat`
```wat
{{#include ../examples/gcd.wat}}
```
Create a bash script that will invoke GCD three times.
## `gcd.sh`
```bash
#!/bin/bash
function gcd() {
# Cast to number; default = 0
local x=$(($1))
local y=$(($2))
# Invoke GCD from module; suppress stderr
local result=$(wasmtime examples/gcd.wat --invoke gcd $x $y 2>/dev/null)
echo "$result"
}
# main
for num in "27 6" "6 27" "42 12"; do
set -- $num
echo "gcd($1, $2) = $(gcd "$1" "$2")"
done
```
