Beefy Boxes and Bandwidth Generously Provided by pair Networks
Perl Monk, Perl Meditation

Re^4: Filename change with regular expression

by Laurent_R (Abbot)
on Aug 09, 2013 at 21:51 UTC ( #1048854=note: print w/replies, xml ) Need Help??

in reply to Re^3: Filename change with regular expression
in thread Filename change with regular expression

Other than decreasing readability and maintainability of the code, I see no purpose of having it as a single regular expression.

I definitely agree. It is often much better to have several regexes is a row, for example to just get rid of all exceptions and special cases, before the regex doing the actual work, rather than trying to pack everything into a single complicated regex.

For example, suppose that you don't want to apply your substitution on file lines that start with XYZ, contain ZYX or XZY or end with YZZ. Trying to put all this in your single s/// substitution is quickly becoming a nighmare, while something like this is very clear:

while (<$IN>) { next if /^XYZ/ or /ZYX/ or /XZY/ or /YZZ$/; # removes all special + cases where substitution should not occur s/foo/bar/g; # do something with $_ }

In the case of the OP, this might be something like this:

foreach $file (@filelist) { next unless file =~ /_00001\.\w+$/; # now only start for looking for a random number to replace _0000 +1 # ... }

Log In?

What's my password?
Create A New User
Node Status?
node history
Node Type: note [id://1048854]
[MidLifeXis]: corelist Typo. Wow. Time to go, fingers are malfunctioning.
[marioroy]: Thanks MidLifeXis. Leaned another thing about Perl. Wow.
[marioroy]: Didn't know of corelist until today. Cool.
[marioroy]: Lady_Aleena Which module?

How do I use this? | Other CB clients
Other Users?
Others contemplating the Monastery: (11)
As of 2017-05-24 18:01 GMT
Find Nodes?
    Voting Booth?