Re: Your favorite objects NOT of the hashref phylum

[codeacrobat]

A stopwatch for example.

package Stopwatch;
sub new{bless \$_[1], $_[0]} 
sub diff{`date +%s` - ${$_[0]}}
$a=new Stopwatch(`date +%s`);
sleep rand()*10; 
print "I slept for ", $a->diff, " seconds\n";

[xdg]

How about just using the builtin Perl function time instead of backticks and the unix date function?

[codeacrobat]

Thanx, sometimes I forget the simplest things. I just needed a quick example illustrating the Stopwatch. I guess the reason I forgot about time is that there are so many similar functions (time, times, gmtime, localtime, asctime, mktime, andwhatnottime).
It's good to have the backticks if you got lost but know a non-perl alternative.

[xdg]

Thanx, sometimes I forget the simplest things

Me, too. Sometimes, I find there's nothing for it but a good skim through perlfunc, which has a nicely categorized list of all the built-in functions (and has all the long descriptions that perldoc -f gives you).

[Anonymous Monk]

I remember using date in a log function once as a Perl junior. I finally noticed it because my code was taking a while to run, so I did my first ever profiling run on it. The backtick date was consuming 60% of the CPU time for the entire process.

[codeacrobat]

It looks like it is more than 60% (cygwin, samsung x25). It does not matter whether you use backticks or a regular open to the date program, both are equally slow.


$ time perl -e 'do {open PROGRAM, "date +%s|" or die "can not open dat
+e $!";$time = <PROGRAM>;close PROGRAM} for 0 .. 1000'

real    0m14.733s
user    0m32.927s
sys     0m9.109s

$ time perl -e 'do { $time = `date +%s`} for 0 .. 1000'

real    0m14.717s
user    0m32.929s
sys     0m9.138s

$ time perl -e 'do { $time = time} for 0 .. 1000'

real    0m0.084s
user    0m0.061s
sys     0m0.046s