git-hooks/commit-msg

#!/bin/sh
#
# An example hook script to check the commit log message.
# Called by git-commit with one argument, the name of the file
# that has the commit message.  The hook should exit with non-zero
# status after issuing an appropriate message if it wants to stop the
# commit.  The hook is allowed to edit the commit message file.
#
# To enable this hook, make this file executable.

# Uncomment the below to add a Signed-off-by line to the message.
# SOB=$(git var GIT_AUTHOR_IDENT | sed -n 's/^\(.*>\).*$/Signed-off-by: \1/p')
# grep -qs "^$SOB" "$1" || echo "$SOB" >> "$1"

# This example catches duplicate Signed-off-by lines.

abort() {
    cp $1 $1.save
    cat >&2 <<EOF
Commit aborted, your commit message was saved as '$1.save'.

Reason: $2

EOF
    exit 1
}

test "" = "$(grep '^Signed-off-by: ' "$1" |
	 sort | uniq -c | sed -e '/^[ 	]*1[ 	]/d')" || {
	abort "$1" "Duplicate Signed-off-by lines."
}

# Check that the first line exists, and is not an asterisk

if [ -z "`head -n 1 $1 | grep -v '^[ \t]*\*$'`" ] ; then
    abort "$1" "Please provide the general description on the first line."
fi

# ...and that it is not too long

if [ "`head -n 1 $1 | wc -c`" -gt 79 ] ; then
    abort "$1" "The first line is too long, please try to fit into 79 characters."
fi

# ...and that it does not continue on the second line
if [ "`wc -l < $1`" -gt 1 -a -n "`head -n 2 $1 | tail -n 1 | sed 's/^#.*//'`" ] ; then
    abort "$1" "The second line is not empty - maybe the first line continues there?"
fi

# Check that the message is not a ChangeLog-like one

if [ -n "`head -n 1 $1 | grep '^[0-9]\{4\}-[0-9]\{2\}-[0-9]\{2\}.*<.*@.*>'`" ] ; then
    abort "$1" "The commit message looks like ChangeLog, please use the git form."
fi

# Check for whitespace in front of *'s

if [ -n "`grep '^[[:space:]]\+\*.*:' $1`" -a -z "`grep '^\*' $1`" ] ; then
    abort "$1" "Please don't use whitespace in front of '* file: Description.' entries."
fi

exit 0