Find and replace punctuation character in first column for multiple text files

Question

Need a solution similar to this post (Find and replace a particular term in multiple files) but for a punctuation character replacement in the first column of each delimited tab text file.

Example:

file1.txt
afile2.txt
3file.txt
...

all other file names end with .txt

Format of txt files has a "tab" in between column and look like:

aaaa:bbb    second_column    third_column
w:xyz    another_second_column    another_third_column

I need to replace the : in the first column to another character such as ##.

Please help.

Does perl treat the : character as a column cutter?

Based on your comments, I get the feeling that you are asking [The Wrong Question](http://english.stackexchange.com/q/45154/13917). Why do you want to remove the colon? It is not a meta character in perl. — TLP, Oct 28 '11 at 14:10

jfs · Accepted Answer · 2011-10-28T17:20:40.620

3

Replace inplace the first colon in the first tab-delimited column in a line by ##:

perl -i.bak -pe's/^([^\t:]*):/$1##/' *.txt

It processes all .txt-files in the current directory saving backup versions to .bak-files.

Here's a variant that doesn't require the capture (suggested by @Brad Gilbert in the comments):

perl -i.bak -pe's/^[^\t:]*\K:/##/' *.txt

Both scripts produce the same result.

edited Oct 28 '11 at 17:20

answered Oct 28 '11 at 13:22

jfs

1

`s/:/##/` would be enough. However +1. – Toto Oct 28 '11 at 13:29
I get the first column chopped off whenever there is a ":" character. That's why I need the replacement. What does ":" do in perl? Yes, the ^\t will leave the 2nd and 3rd column untouched. – horkust Oct 28 '11 at 13:31
@M42: It the first column doesn't have `:` then `s/:/##/` is wrong. – jfs Oct 28 '11 at 13:35
@horkust: Construct a minimal example that demonstrates your problem (with the smallest input, your code that processes it, expected output, and what you get instead) and [post it as a question](http://stackoverflow.com/questions/ask). – jfs Oct 28 '11 at 13:38
`perl -i.bak -pe's/^[^\t:]*\K:/##/' *.txt` works on newer versions of Perl – Brad Gilbert Oct 28 '11 at 17:22

1 Answers1