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I have file with the value say which is delimited with |


I need to pick the column values which end with -, the column picked up should be a numeric value and then move the - to start of the value.

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could you add an example, it a bit unclear what you want to do – Kiwy Mar 25 '14 at 9:43


sed ':1

Or with awk in a more intuitive way:

awk -F '|' -v 'OFS=|' '{
  for (i = 1; i <= NF; i++)
    if ($i ~ /^[0-9]*(\.[0-9]+)?-$/)
      $i = "-" substr($i, 1, length($i)-1)

(that version is stricter in what it considers to be a number, the sed one would accept 1...2 as a number for instance).

On your input, that gives:

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You can do it by anchoring the match to the beginning of the line or a separator. For example with a GNU sed extended regular expression:

sed -r ':a; s/(^|\|)([0-9.]+)-(\||$)/\1-\2\3/; ta' infile


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Hi Thor, Executed with the follwing command it throws a error sed -r 's/(^|\|)([0-9.]+)-/\1-\2/g' d1.txt sed: illegal option -- r Usage: sed [-n] [-e script] [-f source_file] [file...] – Meghana Prakash Mar 25 '14 at 10:10
@MeghanaPrakash: This was tested with GNU sed. Which version of sed are you using? – Thor Mar 25 '14 at 10:11
@StephaneChazelas: good point, I added a terminal anchor as well, thanks. – Thor Mar 25 '14 at 10:15
Hi Thor, it works now thank you very much :) – Meghana Prakash Mar 25 '14 at 10:21
@StephaneChazelas: Interesting, this seems to be because of overlapping matches. It can be fixed by looping, as you have already found. – Thor Mar 25 '14 at 10:24

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