pre-receive git hook for checking bad unicode

pre-receive.sh

#!/bin/bash

# pre-receive hook to check damaged unicode encoding of received text files
# Wonderful ASCII art is borrowed from the phabricator.com project and licensed by the Apache 2.0 license

RESULT=0
while read oldrev newrev refname
do
	OLDIFS=$IFS
	IFS=$'\n'
	for FILE in `git diff-tree -r --name-only $oldrev..$newrev`
	do
		#echo "Looking to $oldrev:$newrev:$FILE" >&2
		git cat-file -e $newrev:$FILE 2>/dev/null
		# checks only existing files
		if [ "$?" = "0" ] ; then
			# checks only non-binary files
			if [ "`git show $newrev:$FILE | file -b --mime-encoding - 2>/dev/null`" != "binary" ] ; then
				# check if a file could be converted to the cp1251 (cyrillic one-byte encoding)
				git show $newrev:$FILE | iconv -f utf-8 -t cp1251 > /dev/null
				if [ "$?" != "0" ] ; then
						echo "File $FILE contains damaged unicode symbols" >&2
						RESULT=1
				fi
			fi
		fi
	done
	IFS=$OLDIFS
done

if [ "$RESULT" != "0" ] ; then
	echo '' >&2
	echo '+---------------------------------------------------------------+' >&2
	echo '|      * * * PUSH REJECTED BY EVIL DRAGON BUREAUCRATS * * *     |' >&2
	echo '+---------------------------------------------------------------+' >&2
	echo '            \                                                    ' >&2
	echo '             \                    ^    /^                        ' >&2
	echo '              \                  / \  // \                       ' >&2
	echo '               \   |\___/|      /   \//  .\                      ' >&2
	echo '                \  /V  V  \__  /    //  | \ \           *----*   ' >&2
	echo '                  /     /  \/_/    //   |  \  \          \   |   ' >&2
	echo '                  @___@`    \/_   //    |   \   \         \/\ \  ' >&2
	echo '                 0/0/|       \/_ //     |    \    \         \  \ ' >&2
	echo '             0/0/0/0/|        \///      |     \     \       |  | ' >&2
	echo '          0/0/0/0/0/_|_ /   (  //       |      \     _\     |  / ' >&2
	echo '       0/0/0/0/0/0/`/,_ _ _/  ) ; -.    |    _ _\.-~       /   / ' >&2
	echo '                   ,-}        _      *-.|.-~-.           .~    ~ ' >&2
	echo '  \     \__/        `/\      /                 ~-. _ .-~      /  ' >&2
	echo '   \____(Oo)           *.   }            {                   /   ' >&2
	echo '   (    (--)          .----~-.\        \-`                 .~    ' >&2
	echo '   //__\\  \ DENIED!  ///.----..<        \             _ -~      ' >&2
	echo '  //    \\               ///-._ _ _ _ _ _ _{^ - - - - ~          ' >&2
	echo '                                                                 ' >&2
	echo '' >&2
fi
exit $RESULT