rmate as $PAGER shell variable (instead of less or whatever you use)

rmatein

#!/bin/sh

# EDITOR should be set to rmate
# Usage: git diff | rmatein
# First arg may be set to file extension to hint rmate about file type

if [ -n "${1}" ]; then
	POSTFIX=".${1}"
fi

TMP_FILE=$( mktemp "/tmp/rmateXXXXXXXX${POSTFIX}" )

cat /dev/stdin | ansifilter > $TMP_FILE

$EDITOR $TMP_FILE

rm $TMP_FILE