When I work on code that makes expensive calls to external programs, I mock the dynamic data with cat. I make a static copy of real output (e.g. $ du / > du.txt ) and then I change $binary in my script. 

my $du = '/bin/du';
defined $DEBUG and $du = '/bin/cat ./du.txt';

[download]

Perhaps something like that could work for you.

In reply to Re: mocking or trapping system calls by rowdog
in thread mocking or trapping system calls by wu-lee

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