In PHP, strings are concatenated together as follows:
$foo = "Hello";
$foo .= " World";
Here, $foo
becomes "Hello World".
How is this accomplished in Bash?
foo="Hello"
foo="${foo} World"
echo "${foo}"
> Hello World
In general to concatenate two variables you can just write them one after another:
a='Hello'
b='World'
c="${a} ${b}"
echo "${c}"
> Hello World