sed or awk? space between numbers and letters and line break

I need a command that separates the numbers from the letters, add points at the end of the numbers, and insert a line break

example

input

1when an unknown printer 22took a galley of type and 3scrambled it to 99make a type specimen book. It has 89survived not only five centuries, 21but also the leap into 37electronic typesetting, remaining 8essentially unchanged. 7It was popularised in the

output

1. when an unknown printer

22. took a galley of type and

3. scrambled it to

99. make a type specimen book. It has

89. survived not only five centuries,

21. but also the leap into

37. electronic typesetting, remaining 8essentially unchanged.

7. It was popularised in the

Well, if you need it, you must have made an attempt to resolve your requirement. So, what is your solution ?.

Welcome. I'd use perl for that. You could do something with AWK by taking advantage of the fact that the Field Separator (FS) can be set to a pattern. However, it all comes down to what you have tried so far and where you are stuck. Please show what you have so far and where it is stuck so we know what approach you are working on and your approximate level.

Trivial with sed.

I was able to separate the numbers from the letters

sed -r 's/([0-9])([a-zA-Z])/\1 \2/g; s/([a-zA-Z])([0-9])/\1 \2/g' input > output

observation, I wanted to apologize for my English :P
I'm not very fluent in English
who can help
I will be really grateful

So you understand sed concepts ok. Concentrate on what you care about - just the numerics. Use of repetition operator after a bracket expression indicates multiple of the same type - so "[0-9]+" means "1 or more digits". In addition to the capture groups you used, there is also the special case of "&" for what actually matched. You can also add newline characters. So try this instead.

sed -r 's/[0-9]+/\n\n&. /g'

It's not quite what you need, but shows the sort of sed features that will work for you.

perfect! Thank you very much.