Need help constructing a one-liner

nr0mx has asked for the wisdom of the Perl Monks concerning the following question:

I have the below script that splits a line on a comma, and adds two new columns in the line by copying column 3 & 4. I need to turn this into a in-place edit one-liner. A regexp seems to be the way to go, but I can't see the solution. Any help appreciated.



while(<DATA>)
{
    my @array = split(/,/);
    print join(',',@array[0..3]),",$array[3],$array[4],",join(',',@arr
+ay[4..$#array]);
}

__DATA__    
20110_1,1155,30,20110_1_3,0,0,65,0,0,99,20,20,14,0,23,2001-08-01 00:00
+,2001-09-18 00:00,0,,0,
20110_2,1155,30,20110_2_3,0,0,65,0,0,99,20,20,14,0,23,2001-08-01 00:00
+,2001-09-18 00:00,0,,0,
20110_3,1155,30,20110_3_3,0,0,65,0,0,99,20,20,14,0,23,2001-08-01 00:00
+,2001-09-18 00:00,0,,0,
[download]

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Re: Need help constructing a one-liner by jeffa (Bishop) on Dec 02, 2003 at 13:29 UTC
How about using autosplit mode? `perl -F, -lape'join(",",@F[0..3],$F[3],$F[4],@F[4..$#F])' data.txt` [download] I like to start out with something like: `perl -F, -MData::Dumper -lape'Dumper \@F' data.txt` [download] To make sure that i am populating @F correctly first, then move on. Once you feel comfortable, you can add inplace editting: `perl -F, -lapi.bak -e'$_=join(",",@F[0..3],$F[3],$F[4],@F[4..$#F])' da +ta.txt` [download] UPDATE: replaced -lane with -lape and dropped print ... silly /me ;) UPDATE2: fixed error pointed out by nr0mx and duff ... thanks guys :) jeffa L-LL-L--L-LL-L--L-LL-L-- -R--R-RR-R--R-RR-R--R-RR B--B--B--B--B--B--B--B-- H---H---H---H---H---H--- (the triplet paradiddle with high-hat)	[reply] [d/l] [select]
Re: Re: Need help constructing a one-liner by duff (Parson) on Dec 02, 2003 at 14:54 UTC
You know, you can do this too: `perl -F, -lapi.bak -e'$_=join(",",@F[0..3,3,4,4..$#F])' data.txt` [download] Not that we're golfing or anything :-) Oh, and you forgot your assignment to `$_`. Otherwise it won't print what you want PerlJam	[reply] [d/l] [select]
Re: Re: Need help constructing a one-liner by nr0mx (Scribe) on Dec 02, 2003 at 14:17 UTC
Thanks, that worked splendidly! I had to reassign the join back to $_, but ths is exactly what I had been looking for.	[reply]
Re: Need help constructing a one-liner by exussum0 (Vicar) on Dec 02, 2003 at 12:59 UTC
What you have now would work as a one liner, assuming you are going for `perl -e`. If you are playing golf, I'd suspect trying somethign like.. `$_=~s/^(([^,]+,){4})([^,]+,[^,]+)/$1"$3"/;` would work too. Nothing is wrong with what you have though. I think it's much clearer. Play that funky music white boy..	[reply] [d/l]