#!/usr/bin/env bash
# dynamic_scope_demo_fixed.sh
 
############################
# global variables (all start at 0)
############################
a=0; b=0; c=0; d=0
 
############################
# g1, g2, g3
############################
g1 () {                 # g1(int b ; int c)
    local b=$1 c=$2
    printf '%d %d %d %d\n' "$a" "$b" "$c" "${d:-0}"
}
 
g2 () {                 # g2(int a ; int c)
    local a=$1 c=$2
    g1 "$a" "$c"
}
 
g3 () {                 # g3(int c ; int a)
    local c=$1 a=$2
    local b=3
    g1 "$a" "$b"        # line 1
 
    (                   # --- begin inner block in a *sub-shell*
        local c=8
        local d=4
        g2 "$a" "$b"    # line 2   (d == 4 is visible here)
    )                   # --- end inner block (d & c disappear)
 
    g1 "$a" "$b"        # line 3   (d fell back to global 0)
    printf '%d\n' "$b"  # “return” value
}
 
############################
# main
############################
main () {
    local a=4
    local b=5
    a=$(g3 "$b" "$c")   # c == 0 (global)
    g3 "$b" "$a"
}
 
main
 

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