I have the following data, and I need to put it all into one line.
I have this:
22791
;
14336
;
22821
;
34653
;
21491
;
25522
;
33238
;
>
Assuming you only want to keep the digits and the semicolons, the following should do the trick assuming there are no major encoding issues, though it will also remove the very last "newline":
$ tr -cd ";0-9"
You can easily modify the above to include other characters, e.g. if you want to retain decimal points, commas, etc.