Beefy Boxes and Bandwidth Generously Provided by pair Networks
The stupid question is the question not asked

Is this concise enough? (code)

by deprecated (Priest)
on Jun 24, 2001 at 01:30 UTC ( #91008=perlquestion: print w/ replies, xml ) Need Help??
deprecated has asked for the wisdom of the Perl Monks concerning the following question:

Yes, I am using perl where I could just be using the shell. In this case, I am using perl because it is a little less processor intense (fewer processes forked), and a lot clearer from a readability point of view.

The application is a wrapper around a tape stacker. I want to read in six tapes from a stacker, in sequence, using the command `mtx`. I'm reading its output, here:

slot_1 Full slot_2 Full slot_3 Empty slot_4 Full slot_5 Full slot_6 Full Drive: tape 3 loaded

I can then figure out which tape is in the drive and which ones need to be done. Anyhow, the code that I have created to parse that information is here:

# status in this case is the output of mtx, above... my @fields = split m[\n|\s+], $status, 13; my $loaded = pop @fields; my %drives = @fields;
This is pretty cool, but I dont get a feeling of satisfaction from it. What would be a more concise yet still clear way to do this?

brother dep

Laziness, Impatience, Hubris, and Generosity.

Comment on Is this concise enough? (code)
Select or Download Code
Re: Is this concise enough? (code)
by particle (Vicar) on Jun 24, 2001 at 04:31 UTC
    well this looked fun so i gave it a shot:
    # using your output in var $status my (%drives, $loaded); # remove last line from $status and assign to $loaded # of course, this assumes nice, predictable output, since # it's simply looking for the word Drive: $status =~ s/\n(Drive:.+)$// && ($loaded = $1); # create your hash with the remainder of $status %drives = split( m[\n|\s+], $status, 12 );
    i think your way is clearer, but it was an interesting diversion. at least now if i see some better examples, i'll have a good idea of what they're doing.

    i tried, but i couldn't find any functions with side effects that could be put to good use here.


(tye)Re: Is this concise enough? (code)
by tye (Cardinal) on Jun 24, 2001 at 10:20 UTC
    my( $loaded, %drives )= ( split m[\s+], $status, 13 )[12,0..11];
            - tye (but my friends call me "Tye")
Re: Is this concise enough? (code)
by chipmunk (Parson) on Jun 24, 2001 at 18:08 UTC
    The regular expression you've used in the split is a bit odd. \s+ matches \n, so the regex is mostly redundant. The one difference can be seen with these two snippets:
    my @fields = split ' ', "abc\n def"; my @fields = split /\n|\s+/, "abc\n def";
    The first splits on "\n ", producing ('abc', 'def'), while the second splits on "\n" and " ", producing ('abc', '', 'def'). In other words, split /\n|\s+/ will give you null strings where there's a newline followed by whitespace (including blank lines).

    One other point; your code depends on having exactly six slots. You might consider writing it to work with any number of slots.

Log In?

What's my password?
Create A New User
Node Status?
node history
Node Type: perlquestion [id://91008]
Approved by root
and the web crawler heard nothing...

How do I use this? | Other CB clients
Other Users?
Others surveying the Monastery: (16)
As of 2015-07-06 17:07 GMT
Find Nodes?
    Voting Booth?

    The top three priorities of my open tasks are (in descending order of likelihood to be worked on) ...

    Results (77 votes), past polls