Beefy Boxes and Bandwidth Generously Provided by pair Networks
Think about Loose Coupling
 
PerlMonks  

Re: When exactly do Perl regex's require a full match on a string?

by jethro (Monsignor)
on Feb 08, 2009 at 14:34 UTC ( #742259=note: print w/replies, xml ) Need Help??


in reply to When exactly do Perl regex's require a full match on a string?

Without any modifiers $ matches the end of the string. But for practical reasons it sort of ignores a newline there. The practical reason is that you often read in lines from files and want to match without first having to chomp the line. A convenience for very small scripts and one liners. Here is a relevant citation from the perlre man page:

By default, the "^" character is guaranteed to match only the beginning of the string, the "$" character only the end (or before the newline at the end), and Perl does certain optimizations with the assumption that the string contains only one line. Embedded newlines will not be matched by "^" or "$". You may, however, wish to treat a string as a multi-line buffer, such that the "^" will match after any newline within the string (except if the newline is the last character in the string), and "$" will match before any newline. At the cost of a little more overhead, you can do this by using the /m modifier on the pattern match operator. (Older programs did this by setting $*, but this practice has been removed in perl 5.9.)

  • Comment on Re: When exactly do Perl regex's require a full match on a string?

Log In?
Username:
Password:

What's my password?
Create A New User
Node Status?
node history
Node Type: note [id://742259]
help
Chatterbox?
[ambrus]: t squished between two other people?
holli is about to take the first hit since a month and this weed is strong shit. Should my head explode, someone call 911.
[ambrus]: And even when I traveled on a big plane for a long flight, it had 3 seats, then corridor, then 4 seats, then corridor, then 3 seats, so less than half of the people sit between two other dudes.
[1nickt]: you are missing an entire element, which is that your base ticket price only gets you a middle seat. If you want to be window or aisle you must pay, or gamble that you'll be assigned there at ...
[1nickt]: ... flihght time (hoping that not enough others have paid and there are some "good" seats to be allotted.
[1nickt]: And this is in addition to paying extra if you want to be in the first 12 rows, or in the emergency exit row.
choroba was once seeted besides a guy that was so fat he was almost squished between the guy

How do I use this? | Other CB clients
Other Users?
Others musing on the Monastery: (12)
As of 2017-12-18 13:42 GMT
Sections?
Information?
Find Nodes?
Leftovers?
    Voting Booth?
    What programming language do you hate the most?




















    Results (486 votes). Check out past polls.

    Notices?