ファイル中のASCII文字以外の文字を消す ref: http://qiita.com/items/fd0b89955d18fb21a3ae

rmnonasciichars.sh

#!/bin/sh
usage() {
    echo Usage: $0 [OPTIONS] DIRECTORY FILEPATTERN
    echo;
    echo "\t\tOPTIONS equivalent to OPTIONS of sed"
}
case "$#" in
    2) find $1 -name $2 | xargs sed -e 's/[^\x00-\x7E]//g' | less;;
    3) find $2 -name $3 | xargs sed $1 's/[^\x00-\x7E]//g';;
    *) usage;;
esac