How to reverse lines of a text file?

Question

I\'m writing a small shell script that needs to reverse the lines of a text file. Is there a standard filter command to do this sort of thing?

My specific applicatio

Answer 1

rev <name of your text file.txt>

You can even do this:

echo <whatever you want to type>|rev

Answer 2

There is a standard command for your purpose:

tail -r file.txt

prints the lines of file.txt in reverse order!

Answer 3

In GNU coreutils, there's tac(1)

Answer 4

Similar to the sed example above, using perl - maybe more memorable (depending on how your brain is wired):

perl -e 'print reverse <>'

Answer 5

Answer is not 42 but tac.

Edit: Slower but more memory consuming using sed

sed 'x;1!H;$!d;x'

and even longer

perl -e'print reverse<>'

Answer 6

cat -b only numbers nonblank lines"

If that's the only issue you want to avoid, then why not use "cat -n" to number all the lines?