Hi Monks, I would like to keep track of the total time of sleep() seconds my program got (in main and across ALL modules).

So what I would like to do is to have a counter in my main which initially is set to zero. And override sleep() so that it increments the counter and then sleeps.

I thought it would be easy to copy builtin sleep() to actual_sleep() and then re-implement my own sleep() which will modify the counter AND sleep. Alas it is not ... Here is a short demo:

#!/usr/bin/env perl
use strict;
use warnings;
my $total_sleep_time = 0;
BEGIN {
*actual_sleep = *CORE::GLOBAL::sleep; # ?????
*CORE::GLOBAL::sleep = sub { $total_sleep_time+=$_[0]; actual_sleep($_
+[0]) } # << line 7
}

# use this module and the other
# ...

sleep(2);
print "total sleep is $total_sleep_time\n";

[download]

the result is:

Deep recursion on anonymous subroutine at xx line 7.

How can I make actual_sleep() point to the original sleep() builtin and not, by the looks of it, to the new sleep()?

Thanks, bliako

Update: The eventual solution provided by LanX is not to rename sleep() to actual_sleep() but to use the original sleep() code which resides untouched in CORE even after overriding its alias in CORE::GLOBAL.

a summary of provided solutions from below:

LanX's solution to 

simply call CORE::sleep()
worked (Re: Copy a builtin sub to a different name and then override) and also worked when sleep() is called from any other package.

beech provided working code based on that (Re: Copy a builtin sub to a different name and then override).

pme made the suggestion to use sleep()'s return value which is the actual seconds slept (Re^3: Copy a builtin sub to a different name and then override).

Useful links: pme suggested reading ex::override which is an easy way to override builtins, alas not "renaming", also CORE. I only had in mind Perl Cookbook's https://docstore.mik.ua/orelly/perl4/cook/ch12_14.htm which also does not mention how to "rename".

Update2:

Most importantly, the new sleep() will be seen only be those packages whose use follows the BEGIN block with the re-aliased sleep() code. See Re^3: Copy a builtin sub to a different name and then override by BillKSmith.

(in order ot timestamps)

Thanks again. Perl is great.

In reply to Copy a builtin sub to a different name and then override by bliako

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