for func in $*; do
    for file in `find sysdeps -name "${func}.c"`;
    do
        script=/tmp/foo$$;
        ( echo "%s/${func}/__&/g";
        echo x )>$script ;
        ex $file <$script ;
        newfile=`echo $file | sed "s/${func}/__&/"`;
        mv $file $newfile;
        echo $newfile;
    done
done