shell replace cr\lf by comma

Question

I have input.txt

1
2
3
4
5

I need to get such output.txt

1,2,3,4,5

How to do it?

Answer 1

tr and sed used be very good but when it comes to file parsing and regex you can't beat perl (Not sure why people think that sed and tr are closer to shell than perl... )

perl -pe 's/\n/$1,/' your_file

if you want pure shell to do it then look at string matching

${string/#substring/replacement}

Answer 2

Try this:

tr '\n' ',' < input.txt > output.txt