Functions Can Set Globals

The title says it all. Shell variables are global by default.

#!/bin/bash

fezmo=6
jo_mamma() {
 fezmo=9
}

echo before call fezmo is $fezmo
jo_mamma
echo after call fezmo is $fezmo

That means that you have to keep track of the names of every variable you set in a function. Bummer. Shell scripts aren't typically very long, so this usually isn't a big deal. Still, using local inside functions is a good habit to get into.

#!/bin/bash

fezmo=6
jo_mamma() {
 local fezmo=9
}

echo before call fezmo is $fezmo
jo_mamma
echo after call fezmo is $fezmo

(Don't just read these examples and nod your head. Use snarf-N-barf to try them.)