#!/bin/sh
var=345
func_a ()
{
local var=123
echo "local: $var"
echo 'invoke func_b from func_a: ' `func_b`
}
func_b ()
{
echo "global: $var"
}


func_a	
func_b

local: 123
invoke func_b from func_a:  global: 123
global: 345

cat test 
#!/bin/bash

function a () {
local z=1;
echo "\"z\" in function = $z"
}

function b () {
a
echo "${z}"
}

a
b
echo "\"z\" outside function = $z"

# и результаты:
$ sh test 
"z" in function = 1
"z" in function = 1

"z" outside function =