Why use external commands when everything and more is already available?

$ perl -V:ptrsize
ptrsize='8';
$ perl -MConfig -wE'say $Config{ptrsize}'
8
$ perl -MData::Peek -MConfig::Perl::V -we'DDumper (Config::Perl::V::my
+config ()->{config})'
[download]

Tux,

Very Nice!

but... something to keep in mind:

• You may not be able in install CPAN modules in a production system.

I tested the performance on a test system:

# *Your method* after installing 2 CPAN modules
 real   0m0.84s
 user   0m0.76s
 sys    0m0.008s

# *My method* calling Perl from the command line
 real   0m0.028s
 user   0m0.032s       # Note: I did this 3 times and 'user' > 'real' 
+was every time???
 sys    0m0.004s
[download]

Granted your routines providing a lot of information, but doing a 'system' call to get some specific information may not be that bad of a hit.

I'm still going to add this to my bag of tricks. Good job!

Regards...Ed

"Well done is better than well said." - Benjamin Franklin

The first two are CORE capabilities since perl5.003_07. Sorry to sound harsh, but whining that you cannot install from CPAN is bullshit, that is repeated over and over and over again with all possible workarounds here on PM.

Nagging about startup time might be true for Config::Perl::V, which does quite a bit more than we'd love to just to be able to get the info (not true anymore on perl-5.18, where that info is available directly from CORE, as is Config::Perl::V). The extra time you see is the dumper time, which was just used to show you the content. Try again with just accessing the data required and you will see a considerable speedup. IMHO all those speeds are just noise in the complete picture, but I do not want to compare apples and pears.

Nagging about Config is just trying to find sand to throw into the engine. You have no idea how many modules use Config, so it will be loaded anyway sooner or later.

$ find 5.18.0 -name \*.pm | xargs grep -wl 'use Config' | wc -l
57
$ find site_perl/5.18.0 -name \*.pm | xargs grep -wl 'use Config' | wc
+ -l
107
$ corelist Config Config::Perl::V

Data for 2013-08-20
Config was first released with perl 5.00307

Data for 2013-08-20
Config::Perl::V was first released with perl v5.17.9
$ time perl -V:ptrsize
ptrsize='4';
0.005u 0.003s 0:00.00 0.0%      0+0k 0+0io 0pf+0w
$ time perl -MConfig -wE'say $Config{ptrsize}'
4
0.001u 0.005s 0:00.00 0.0%      0+0k 0+0io 0pf+0w
$ time perl -MConfig::Perl::V -wE'say Config::Perl::V::myconfig ()->{c
+onfig}{ptrsize}'
4
0.007u 0.002s 0:00.00 0.0%      0+0k 0+0io 0pf+0w
[download]


Enjoy, Have FUN! H.Merijn