foozy@708: $ \textbf{cat .hg/hgrc}
foozy@708: [hooks]
foozy@708: pretxncommit.whitespace = hg export tip | (! egrep -q '^\textbackslash{}+.*[ \textbackslash{}t]$')
foozy@708: $ \textbf{echo 'a ' > a}
foozy@708: $ \textbf{hg commit -A -m 'test with trailing whitespace'}
foozy@708: adding a
foozy@708: transaction abort!
foozy@708: rollback completed
foozy@708: abort: pretxncommit.whitespace hook exited with status 1
foozy@708: $ \textbf{echo 'a' > a}
foozy@708: $ \textbf{hg commit -A -m 'drop trailing whitespace and try again'}