1 # diffstat
2 
3 Show diff statistics.
4 
5 	#!/usr/bin/awk -f
6 
7 maybe not 100% correct, but it's one case where being simple yet
8 slightly wrong is way easier than correct.  It's not a catastrophe to
9 count some extra lines, while parsing the diff (possibly enclosed in a
10 mail) is hard.
11 
12 	/^\+/ { a++ }
13 	/^\-/ { m++ }
14 
15 Don't be a sink!  Continue the pipeline so we can further save or apply
16 the diff.
17 
18 	// { print $0 }
19 
20 At the end, print the stats to standard error to avoid mangling the
21 input.  Unfortunately, there doesn't seem to be a "built-in" way of
22 printing to stderr other than using the pseudo-device.
23 
24 	END {
25 		print "+", a > "/dev/stderr"
26 		print "-", m  > "/dev/stderr"
27 	}
28 
29 some example usages:
30 
31 * cvs -q di | diffstat | tee /tmp/diff | less
32 * git diff | diffstat > /tmp/diff
33 * got di | diffstat | ssh foo 'cd xyz && got patch'