The always amazing Peteris Krumins is starting a series of blog postings on cool plugins for vim, starting with this post about surround.vim.
Just reading the article about the "old way" to do what surround.vim does was informative, showing me vim tricks I didn't know.
Seriously, anyone who reads Mechanix should have Peteris' blog in her syndication reader.
Too often I see web graphics that have been saved as JPEGs, not PNGs, and I cringe. How can I tell? This comic shows the difference.
By Selena Deckelmann
Last night, an incredible number of people showed up to Code-N-Splode to hear about Git.
I was not at all prepared for that number of people, but grateful that a couple experts were on hand to help - Sarah Sharp, Audrey Eschright and Michael Schwern (and others) all contributed to the discussion. Thanks for all the great questions! I'm looking forward to Sarah’s advanced tutorial next month.
Selena Deckelmann leads the Portland PostgreSQL Users Group and regularly contributes to Code-N-Splode, a group dedicated to getting more women involved in open source. She likes Perl. She'll be running a code sprint and giving a lightning talk on having more fun with open source at PostgreSQL Conference West, on October 17-19, 2008.
Peteris Krumins, the prolific blogger and programmer, decided to explore TCP/IP networking in GNU Awk, and came up with this, a YouTube video downloader.
Subscribe to Peteris' blog. It's well worth reading.
Linux Journal has an article on creating Excel files using Spreadsheet::WriteExcel. It has its quirks, like creating corrupted spreadsheets if you try to populate a cell more than once, but when you need it, there's nothing else to do what it does.
I'm in the middle of a game of Scrabulous with Christoper Humphries on Facebook, and I get "tolkien" handed to me in my tray. Good letters, and I ought to be able to make a bingo out of them. Alas, the best I could get to play on the board was "knot", but what else could I have made? Perl to the rescue!
All I need to do is match across the contents of /usr/share/dict/words in a Perl one-liner. The -n flag means "loop over the input file, but don't print $_". My little program goes in -e, and it looks like this:
$ perl -lne'print if /t/ && /o/ && /l/ && /k/ && /i/ &&
/e/ && /n/' /usr/share/dict/words
allokinetic
ankylopoietic
anticlockwise
automatonlike
bibliokleptomania
....
Lots of good words, but they're awfully long. Let's limit it to seven-letter bingos. We have to use the -l flag to drop the linefeed from the input lines, so the length call is accurate.
$ perl -lne'print if /t/ && /o/ && /l/ && /k/ && /i/ &&
/e/ && /n/ && length($_)==7' /usr/share/dict/words
$
Shoot, nothing there. Let's try eight.
perl -lne'print if /t/ && /o/ && /l/ && /k/ && /i/ &&
/e/ && /n/ && length($_)==8' /usr/share/dict/words
knotlike
townlike
"knotlike"! That would have been beautiful. Oh well. :-(
Thread over on perlmonks talks about Tom Christiansen's assertion that you should use it, by default, even when you only have one command-line argument to parse:
What seems to happen is that at first we just want to add--oh say for example JUST ONE, SINGLE LITTLE -v flag. Well, that's so easy enough to hand-hack, that of course we do so... But just like any other piece of software, these things all seem to have a way of overgrowing their original expectations... Getopt::Long is just *wonderful*, up--I believe--to any job you can come up with for it. Too often its absence means that I've in the long run made more work for myself--or others--by not having used it originally. [Emphasis mine -- Andy]
I can't agree more. I don't care if you use Getopt::Long or Getopt::Declare or Getopt::Lucid or any of the other variants out there. You know know know that you're going to add more arguments down the road, so why not start out right?
Yes, it can be tricky to get through all of its magic if you're unfamiliar with it, but it's pretty obvious when you see enough examples. Take a look at prove or ack for examples. mech-dump is pretty decent as an example as well:
GetOptions(
'user=s' => \$user,
'password=s' => \$pass,
forms => sub { push( @actions, \&dump_forms ); },
links => sub { push( @actions, \&dump_links ); },
images => sub { push( @actions, \&dump_images ); },
all => sub { push( @actions, \&dump_forms, \&dump_links, \&dump_images ); },
absolute => \$absolute,
'agent=s' => \$agent,
'agent-alias=s' => \$agent_alias,
help => sub { pod2usage(1); },
) or pod2usage(2);
Where the value in the hashref is a variable reference, the value gets stored in there. Where it's a sub, that sub gets executed with the arguments passed in. That's the basics, and you don't have to worry about anything else. Your user can pass --abs instead of --absolute if it's unambiguous. You can have mandatory flags, as in agent=s, where --agent must take a string. On and on, it's probably got the functionality you need.
One crucial reminder: You must check the return code of GetOptions. Otherwise, your program will carry on. If someone gives your program an invalid argument on the command-line, then you know that the program cannot possibly be running in the way the user intended. Your program must stop immediately.
Not checking the return of GetOptions is as bad as not checking the return of open. In fact, I think I smell a new Perl Critic policy....
From The Pragmatic Programmer:
What's the value of pi? If you're wondering how much edging to put around a circular flower bed, then "3" is probably good enough. If you're in school, then maybe "22/7" is a good approximation. If you're in NASA, then maybe 12 decimal places will do.
Alfie John over at rental-property.co.nz wrote to tell that the source code for the entire site, written using Mason and Class::DBI, is available for download.
For someone wanting to see an overview of how either Mason or Class::DBI work with real-world examples, not just samples from documentation, this is a great place to start.
Adam Kennedy posted an excellent article about huge performance hits he found with File::Find::Rule. From the docs, there's this sample to find all the *.pm files in @INC:
# Find all the .pm files in @INC my @files = File::Find::Rule->file ->name( '*.pm' ) ->in( @INC );What this search REALLY says is "Find every single file in all these trees, then do an slow IO stat call to the operating system on every single one to work out which ones are files, and only then do a quick regex match on the file names to keep the 5% that have the ending we want and throw away the 95% that don't".
Now I'm worried about if I'm doing the right order of checking in File::Next, a lightweight file finder that ack relies on.
