% stephan@ape (/home/stephan/t0) %
% echo 'just another perl hacker' > secret.txt

% stephan@ape (/home/stephan/t0) %
% zip -P sesame safe.zip secret.txt
  adding: secret.txt (stored 0%)

% stephan@ape (/home/stephan/t0) %
% perl safe_unzip.px sesame safe.zip 
.cmd: [unzip -qoP sesame safe.zip 2>/dev/null]
.okay: got secret file! status = [0]
     1  just another perl hacker$