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

O Wise and Awesome Monks, a text file contains lines of fields seperated by some delimiter; space for example; some lines not all will have in field 2 a value like an inital (e.g., A. or B. or Jr.) for those lines with such a value in field 2, we wish to have that value removed or deleted. We also wish to do this as a one-line. Here's what we have so far. What say you?

c:\perl\bin\perl.exe -e "while (<>) { next if ($F[2] ~= /A-Za-z/\.;) print \"\"}" < text.txt > xt.txt

or

c:\perl\bin\perl.exe -e -i.bak "while (<>) { next if ($F[2] ~= /A-Za-z/\.;) print \"\"}" text.txt

Replies are listed 'Best First'.
Re: On Match Remove Field
by AnomalousMonk (Archbishop) on Mar 03, 2011 at 21:19 UTC

    I would suggest something like (untested):
        perl -ane "print unless $F[2] =~ m{ \A (?: [[:alpha:]] | Jr) \. \z }xms" in.file > out.file
    Update: or with in-place editing (which I didn't notice at first) (also untested):
        perl -i.orig -ane "print unless $F[2] =~ m{ \A (?: [[:alpha:]] | Jr) \. \z }xms" in.file

    See perlrun.

    Update: BTW: What did you say about the results you got when you tried the code in the OP? You did at least try it, didn't you?

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      Code in the OP? What's that?

      Your code prints the lines desired, omits all other lines with a A-Z. in any other field, and prints all lines without a A-Z. (both undesired). We wish to delete only the second field if it contains a period; if it doesn't contain a period, we do nothing and move to the next line.

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Re: On Match Remove Field
by TomDLux (Vicar) on Mar 03, 2011 at 21:27 UTC

    Perl already has the -pi options to edit files line by line, either editing in place or saving a backup file if you use -p -i.bak. Add -a to split each line, same as awk does. if you want to split on a different character other than a space, you can specify it with -F, but you want space splits

    perl -pia -e"splice @F, 1, 1 if  $F[1] =~ /[A-Z]\./i or $F[1] eq 'jr.'
+ "

    [download]

    As Occam said: Entia non sunt multiplicanda praeter necessitatem.

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