Beefy Boxes and Bandwidth Generously Provided by pair Networks
Syntactic Confectionery Delight
 
PerlMonks  

Re: sorting a file by a date:"YYYY-MM-DD" field with cmp

by ikegami (Patriarch)
on Jun 16, 2015 at 17:45 UTC ( [id://1130653]=note: print w/replies, xml ) Need Help??


in reply to sorting a file by a date:"YYYY-MM-DD" field with cmp

In scalar context, the match operator and thus the bind operator returns whether a match was found or not. You want to evaluate the match in list context to get it to return the list of matches.

Fix:

my ($aDate) = $a =~ /\bdate:\s*"(\d{4}-\d{2}-\d{2})"/; my ($bDate) = $b =~ /\bdate:\s*"(\d{4}-\d{2}-\d{2})"/;

Also:

  • Added \b to avoid catching enddate.
  • Added \s* in case the JSON encoder decides to start adding whitespace.
  • Removed some superfluous backslashes.

Note: Will break if you get

  • { date:"\u0032015-05-01", content:"erwa" }
  • { foo:{date:"2014-05-01"}, date:"2015-05-01", content:"erwa" }
  • etc

For a reliable but slower solution, you can use

use JSON::XS qw( decode_json ); my @sorted = map { substr($_, 10) } sort map { decode_json($_)->{date} . $_ } @events;

As for the blank lines, just remove them first using

@events = grep /\S/, @events;

Update: Added to my answer.

Log In?
Username:
Password:

What's my password?
Create A New User
Domain Nodelet?
Node Status?
node history
Node Type: note [id://1130653]
help
Chatterbox?
and the web crawler heard nothing...

How do I use this?Last hourOther CB clients
Other Users?
Others goofing around in the Monastery: (6)
As of 2024-03-28 22:54 GMT
Sections?
Information?
Find Nodes?
Leftovers?
    Voting Booth?

    No recent polls found