Greetings;
Thanks for all that tuteledge. Now if you could expand it to
handle
# processors : 3
col 1...5...10....5...20
that would be great!
Apparently on my ver of linux something is supposed to see
this as a comment and ignore it.
TIA,
Dennis
>}On Apr 29, 14:12, Michael Lamertz wrote:
>} Subject: Re: Getting contens of file into a hash
>On Mon, Apr 29, 2002 at 11:59:42AM +0100, Anders Holm wrote:
>> Hi folks!
>>
>> Could someone point me in the right direction on this one.
>>
>> I'm trying to input /proc/cpuinfo
>> on a Linux box into a hash. This file
>> contains information of the processors on the running machine, what type
>> they are, number of cpu's etc. and I want to use this info later.
>
>Ok, let's look at the data:
>
> ---------- snip ----------
> nijushiho:~$ cat /proc/cpuinfo
> processor : 0
> vendor_id : GenuineIntel
> cpu family : 6
> model : 8
> model name : Pentium III (Coppermine)
> stepping : 6
> cpu MHz : 798.266
> cache size : 256 KB
> fdiv_bug : no
> hlt_bug : no
> f00f_bug : no
> coma_bug : no
> fpu : yes
> fpu_exception : yes
> cpuid level : 2
> wp : yes
> flags : fpu vme de pse tsc msr pae mce cx8 sep mtrr pge mca cmov pat
>pse36 mmx fxsr sse
> bogomips : 1592.52
>
> nijushiho:~$
> ---------- snip ----------
>
>> Now the problem I have is that I'd like to get it into a hash, and I just
>> can't figure out how to do this. I can split it up at the : delimiter, but
>> I'm not sure how then to get in the data in a hash properly.
>
>You're right on track (with some exceptions, but read about that further
>down the page).
>
> my ($key, $value) = split /:/;
>
>will give you e.g.
> $key "cpu family"
> $value "6"
>
>You access the "cells" of a hash via their 'key', and you write the
>value into that cell by using an assignment.
>
> $hash{$key} = $value
>
>Note that most beginners consider it funny that it's written
>
> $hash{$key}
>
>and not
>
> %hash{$key}
>
>The reason for the notation is that the leftmost character describes
>what you have in hand, and not what 'hash' is. So '$hash{$key}' means
>
> The *SCALAR* inside the hash '%hash' at position '$key'
>
>
>The same goes for accessing the content of the hash when reading it out
>later.
>
> print $hash{'cpu family'}
>
>For more information about hashes read
>
> perldoc perldata
>
> perldoc perldsc
> perldoc perlreftut
> perldoc perlref
>
>Start with the first one. The other three will too soon lead you to
>'references' which will add an indirection layer to all your data. Go
>with the basics first, and once you've grokked that, go for the latter.
>
>> More than likely I'm describing this completely wrong, but hey, I'm a
>> newbie.. ;)
>
>Nope, that was pretty ok.
>
>
>Ok, now on to some discussion the use of 'split' here:
>
>*IF* you have full control over your input data, using split is just
>fine. If, however, you're relying on others to not change their output
>you're on thin ice.
>
>Of course you need to make assumptions about the data you're working
>with, but you should optimize on rubustness.
>
>So if someone decides that there's a terrible cool feature for xmyrgl
>CPUs called effectiveness that's to be displayed as a ratio
>
> xmyrgle fx : 3:2
>
>split will give you
>
> 'xmyrgle fx', 3, 2
>
>and since you only assigned that to two variables, your information will
>be broken.
>
>A much saner assumption would be that everything up to the first colon
>will be the key and all the rest will be the value
>
> my ($key, $val) = /\s* # Skip leading whitespace
> ([^\:]*?) # Start with everything not ':'
> # minimize so whitespace gets eaten by
>next statement
> \s* : \s* # Allow whitespace around ':'
> (.*?) # Slurp in all the rest,
> # minimizing again
> \s* # Catch trailing whitespace
> $/x; # x allows fancy display and commenting of
>regexp
>
>Well, that code will break too if somebody considers it cool to use a
>colon inside the name field, but in that case, you'll still have all the
>information available. Nothing is lost, nothing gets thrown away except
>for the whitespace and the colon.
>
>Proof of concept:
>
> ---------- snip ----------
> nijushiho:~$ (cat /proc/cpuinfo; echo ' xmyrgle fx : 3:2 ') |\
> > perl -MData::Dumper -lane '/\s*([^\:]*?)\s*:\s*(.*?)\s*$/ or next;
> > $hash{$1} = $2;
> > END { print Dumper(\%hash) }'
> $VAR1 = {
> 'coma_bug' => 'no',
> 'flags' => 'fpu vme de pse tsc msr pae mce cx8 sep mtrr pge mca cmov
>pat pse36 mmx fxsr sse',
> 'cpu MHz' => '798.266',
> 'wp' => 'yes',
> 'f00f_bug' => 'no',
> 'processor' => '0',
> 'xmyrgle fx' => '3:2', # <=== TADAAA
> 'bogomips' => '1592.52',
> 'vendor_id' => 'GenuineIntel',
> 'stepping' => '6',
> 'cpuid level' => '2',
> 'model name' => 'Pentium III (Coppermine)',
> 'hlt_bug' => 'no',
> 'model' => '8',
> 'fpu' => 'yes',
> 'cache size' => '256 KB',
> 'fdiv_bug' => 'no',
> 'fpu_exception' => 'yes',
> 'cpu family' => '6'
> };
>
> nijushiho:~$
> ---------- snip ----------
>
>Just some "food for thought" (tm)...
>
>PS: use '//x'!
>
>--
> If we fail, we will lose the war.
>
>Michael Lamertz | +49 221 445420 / +49 171 6900 310
>Nordstr. 49 | [EMAIL PROTECTED]
>50733 Cologne | http://www.lamertz.net
>Germany | http://www.perl-ronin.de
>
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>
>}-- End of excerpt from Michael Lamertz
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