Foreach time delay

Anonymous Monk has asked for the wisdom of the Perl Monks concerning the following question:

Hi Monks

There is any (easy way) to add a delay into a foreach loop (elaborate each element of the array after x time)? The following of course doesn't work.

#!/usr/bin/perl -w

use strict;

foreach (1..20) {
    print "a";
    sleep (1);#between each element of the array there should be 1 sec
+ond interval
} 
print "\n";
[download]

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Re: Foreach time delay by Corion (Patriarch) on Mar 16, 2017 at 10:49 UTC
The above works, but you are Suffering from Buffering. Set autoflush if you want output to STDOUT to appear unbuffered: `$\| = 1;` [download] Alternatively, print newlines: `foreach (1..20) { print "a\n"; sleep (1);#between each element of the array there should be 1 sec +ond interval }` [download]	[reply] [d/l] [select]
Re^2: Foreach time delay by Anonymous Monk on Mar 16, 2017 at 10:55 UTC
Thanks Corion, you opend a new world for me. Fantastic!	[reply]
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Re^2: Foreach time delay by Anonymous Monk on Mar 16, 2017 at 15:14 UTC
Is there any good reason why we're still line-buffering stdout? It seems like a throwback to the timesharing days. This is the 21st century, people!	[reply]
Re^3: Foreach time delay by Anonymous Monk on Mar 16, 2017 at 15:41 UTC
Yes there is: "If Perl made a system call for every read operation, that would be 10,001 system calls in all (one extra to detect end-of-file), and if the file was on the disk, it would have to wait for the disk at least 10,000 times. That would be very slow." Can you write a better OS?	[reply]
Re^4: Foreach time delay by Anonymous Monk on Mar 16, 2017 at 17:39 UTC