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[20050729]
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Reversing a file line-by-line (Update #2)
I've been searching for a tool to reverse the contents of a file
line-by line (i.e. print last line first, etc.) for some time, and
found by accident that NetBSD's "tail -r" can do that.
Whee! (Pity that's non in SUSv3)
Update: Julien Gabel pointed me at an article
"Eight Ways to Reverse a File". I knew GNU's 'tac' was there, and all the other
options use some other tools (perl, vi, sed, etc.). Now I find it
funny that the solution I used before I knew "tail -r" isn't listed there:
cat -n file | sort -rn | some sed stuff to get rid off the line numbers.
Update #2:
Martin Neitzel pointed me at another, imho very cute way to solve
the problem with an ed/ex command, following the basic idea of
marking every line, and then moving it to the beginning. Here's
how to do it in vi (load any file first):
g/./m0 or
g/^/m0. Simple, hu? And doesn't need another tool installed. :)
[Tags: compsci]
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