sub do_exec {
   my ($cmd, $args) = @_;
   system("$cmd $args") == 0
      or die "Command '$cmd' failed: $!";
}

sub do_chdir {
   my ($dir) = @_;
   chdir $dir or die "Couldn't change dir to '$dir': $!";
}

sub run {
   do_exec('foo', '--bar baz');
   do_chdir('foobar');
   do_exec('foo', '--bar baz2');
   do_exec('foo2', '--bar baz');
   do_chdir('..');
   do_exec('bar', '--foo baz');
}

run();
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