grep: extend functionality, add man page entry, add unit test. walkchangerevs now returns a two-tuple. Its behaviour is also extensively commented. The annotate command's getname function has been factored out to a new function, trimname, so it can be shared between annotate and grep. The behaviour of grep has been beefed up, so that it now performs a number of useful functions.

#!/bin/sh -e

umask 027
mkdir test1
cd test1

hg init
touch a b
hg add a b
hg ci -m "added a b" -d "0 0"

cd ..
mkdir test2
cd test2

hg init
hg pull ../test1
hg co
chmod +x a
hg ci -m "chmod +x a" -d "0 0"

cd ../test1
echo 123 >>a
hg ci -m "a updated" -d "0 0"

hg pull ../test2
hg heads
hg history

hg -v co -m

ls -l ../test[12]/a > foo
cut -b 0-10 < foo