How to override exit() call in Perl eval block

Question

I need to eval some code in Perl that might some times contain an exit() call in it. A very simplified example of this would be:

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Answer 1

You can override exit, but you must do so at compile-time. So use a flag to signal whether the override is active or not.

our $override_exit = 0;
BEGIN { 
    *CORE::GLOBAL::exit = sub(;$) {
        die "EXIT_OVERRIDE\n" if $override_exit;
        CORE::exit($_[0] // 0);
    };
 }

 eval {
    local $override_exit = 1;
    some_function();
 };

 my $exit_was_called = $@ eq "EXIT_OVERRIDE\n";
 die $@ if $@ && !$exit_was_called;

 warn("Exit was called\n") if $exit_was_called;

But that creates an exception that might be caught unintentionally. So let's use last instead.

our $override_exit = 0;
BEGIN { 
    *CORE::GLOBAL::exit = sub(;$) {
        no warnings qw( exiting );
        last EXIT_OVERRIDE if $override_exit;
        CORE::exit($_[0] // 0);
    };
 }

 my $exit_was_called = 1;
 EXIT_OVERRIDE: {
    local $override_exit = 1;
    eval { some_function() };
    $exit_was_called = 0;
    die $@ if $@;
 }

 warn("Exit was called\n") if $exit_was_called;

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Note that eval BLOCK is used to catch exception. eval EXPR is used to compile code.