Editing just one column in a file

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

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Re: Editing just one column in a file by BrowserUk (Patriarch) on Nov 28, 2011 at 21:54 UTC
`perl -lane '++$F[15]; print join "\t", @F' file` [download] With the rise and rise of 'Social' network sites: 'Computers are making people easier to use everyday' Examine what is said, not who speaks -- Silence betokens consent -- Love the truth but pardon error. "Science is about questioning the status quo. Questioning authority". In the absence of evidence, opinion is indistinguishable from prejudice.	[reply] [d/l]
Re^2: Editing just one column in a file by ZWcarp (Beadle) on Nov 28, 2011 at 22:14 UTC
Ahhh ok brilliant. One more question.. why does this only print one column instead of the specified array range?I'm sure I'm doing something stupid but I can't find a good website or text with detailed stuff on specific command line perl `perl -lane '$,="\t";print $F[0..6]' file.txt` Thanks so much! UPDATE Sorry, I got it, you just need to change the $ to a @ in front of F. Apologies	[reply] [d/l]
Re^2: Editing just one column in a file by vinian (Beadle) on Nov 29, 2011 at 02:04 UTC
hi, i am confused about this, need your help. `echo "Just another perl monkers " \| perl -lane 'print $F[0..3]'` [download] Output: `Just` [download] why it treat `$F[0..3]` as `$F[0]` but not `$F[1]`or `$F[2]`or `$F[3]`.	[reply] [d/l] [select]
Re^3: Editing just one column in a file by BrowserUk (Patriarch) on Nov 29, 2011 at 02:35 UTC
Because the Perl syntax for an array slice is `@a[ ... ]`. If you enable warnings, you'll see that by using `$a[1..3]`, the `1..3` is treated as a flip-flop operator comparing against `$.`, and under most circumstances will produce false, which in the numeric context gets taken as 0: `c:\test>perl -wE"@a = 0..10; say $a[1..3]; say @a[1..3]" Use of uninitialized value in range (or flip) at -e line 1. Argument "" isn't numeric in array element at -e line 1. 0 123` [download] With the rise and rise of 'Social' network sites: 'Computers are making people easier to use everyday' Examine what is said, not who speaks -- Silence betokens consent -- Love the truth but pardon error. "Science is about questioning the status quo. Questioning authority". In the absence of evidence, opinion is indistinguishable from prejudice.	[reply] [d/l] [select]
Re^4: Editing just one column in a file by ZWcarp (Beadle) on Nov 30, 2011 at 20:23 UTC
Re^5: Editing just one column in a file by BrowserUk (Patriarch) on Nov 30, 2011 at 21:12 UTC
Re^4: Editing just one column in a file by vinian (Beadle) on Nov 29, 2011 at 09:00 UTC
Re^5: Editing just one column in a file by choroba (Cardinal) on Nov 29, 2011 at 10:13 UTC
Re^5: Editing just one column in a file by Tux (Canon) on Dec 01, 2011 at 07:35 UTC
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