You could type perldoc -f mkdir from the command prompt to get the documentation for the 'mkdir' function. And I would also check for the return status of mkdir to see if it has succeeded or not.

Another point is that file masks are octal numbers, so that

mkdir 'dir', 700;   # incorrect
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is not the samething as

mkdir 'dir', 0700;  # correct
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Having said that, you can certainly overcome this problem by a subsequent call to 'chmod' -

chmod 'dir', 0700;
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