I have potentially large files that need to be sorted by 1-n keys. Some of these keys might be numeric and some of them might not be. This is a fixed-width columnar file so there are no delimiters.
Is there a good way to do this with Unix sort? With one key it is as simple as using '-n'. I have read the man page and searched Google briefly, but didn't find a good example. How would I go about accomplishing this?
Note: I have ruled out Perl because of the file size potential. It would be a last resort.
Take care though:
If you want to sort the file primarily by field 3, and secondarily by field 2 you want this:
sort -k 3,3 -k 2,2 < inputfile
Not this: sort -k 3 -k 2 < inputfile
which sorts the file by the string from the beginning of field 3 to the end of line (which is potentially unique).
-k, --key=POS1[,POS2] start a key at POS1 (origin 1), end it at POS2
(default end of line)