Is there an elegant way to store and evaluate return values in bash scripts?

Question

I have a rather complex series of commands in bash that ends up returning a meaningful exit code. Various places later in the script need to branch conditionally on whether

Answer 1

The simple solution:

output=$(complex_command)
status=$?

if (( status == 0 )); then
    : stuff with "$output"
fi

: more code

if (( status == 0 )); then
    : stuff with "$output"
fi

Or more eleganter-ish

do_complex_command () { 
    # side effects: global variables
    # store the output in $g_output and the status in $g_status
    g_output=$(
        command -args | commands | grep -q trigger_word
    )
    g_status=$?
}
complex_command_succeeded () {
    test $g_status -eq 0
}
complex_command_output () {
    echo "$g_output"
}

do_complex_command

if complex_command_succeeded; then
    : stuff with "$(complex_command_output)"
fi

: more code

if complex_command_succeeded; then
    : stuff with "$(complex_command_output)"
fi

Or

do_complex_command () { 
    # side effects: global variables
    # store the output in $g_output and the status in $g_status
    g_output=$(
        command -args | commands
    )
    g_status=$?
}
complex_command_output () {
    echo "$g_output"
}
complex_command_contains_keyword () {
    complex_command_output | grep -q "$1"
}

if complex_command_contains_keyword "trigger_word"; then
    : stuff with "$(complex_command_output)"
fi