Source

hgbook / es / examples / hook.msglen

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#!/bin/sh

hg init a
cd a
echo '[hooks]' > .hg/hgrc
echo 'pretxncommit.msglen = test `hg tip --template {desc} | wc -c` -ge 10' >> .hg/hgrc

#$ name: go

cat .hg/hgrc
echo a > a
hg add a
hg commit -A -m 'too short'
hg commit -A -m 'long enough'