Re^2: One liner to S & R by column

If $. is 0 (first line of the file), skip to the next iteration. … On all subsequent iterations $. will no longer be zero…

The number of the first line of the input file is 1, not 0. So you need to use an explicit comparison operation.

    perl -pli.bak -e 'substr($_, 18, 1) =~ tr/Y/H/ if $. > 1' filename
[download]

Here's the same thing using a regular expression.

    perl -pli.bak -e 's/^.{18}\KY/H/ if $. > 1' filename
[download]

Jim

Comment on Re^2: One liner to S & R by column Select or Download Code

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Re^3: One liner to S & R by column by davido (Cardinal) on Dec 23, 2013 at 18:01 UTC
Updated (and documented the change). :) Thanks. Dave	[reply]
Re^4: One liner to S & R by column by Laurent_R (Canon) on Dec 23, 2013 at 18:51 UTC
Hi, you still have this sentence in your original post: "On all subsequent iterations $. will no longer be zero." You will probably want to fix it.	[reply]