use Perl

#!/bin/sh
# new-cygport <old-release> <new-release>
# Sample: new-cygport perl-Win32-GUI-1.0-2 perl-Win32-GUI-1.0.2-1

cp $1.cygport $2.cygport
cp $1.cygwin.patch $2.cygwin.patch
cp $1.src.patch $2.src.patch
PKG=`echo $1 | sed -e 's/\-[^\-]*\-[^\-]*$//'`
VER=`echo $1 | sed -e "s/${PKG}\-//" -e 's/\-[^\-]*$//'`
OLDBASE=${PKG}-${VER}
PKG=`echo $2 | sed -e 's/\-[^\-]*\-[^\-]*$//'`
VER=`echo $2 | sed -e "s/${PKG}\-//" -e 's/\-[^\-]*$//'`
NEWBASE=${PKG}-${VER}

sed -e "s,^--- origsrc/${OLDBASE},--- origsrc/${NEWBASE}," \
    -e "s,^+++ src/${OLDBASE},+++ src/${NEWBASE}," < $1.src.patch > $2.src.patch
sed -e "s,^--- origsrc/${OLDBASE},--- origsrc/${NEWBASE}," \
    -e "s,^+++ src/${OLDBASE},+++ src/${NEWBASE}," < $1.cygwin.patch > $2.cygwin.patch

echo cygport $2.cygport get prep make
echo nano $2/CYGWIN-PATCHES/README
echo cygport $2.cygport mkpatch install check pkg

difforig originally came from the postgresql hackers, but I enhanced it to easier submit simple multifile patches in .orig-polluted working dirs. You can provide a path or multiple files.

#!/bin/sh
echo "difforig $@"
echo ""
/usr/bin/date +"%Y-%m-%d  Reini Urban <rurban@x-ray.at>"
echo ""
if [ "$#" -gt 1 -o -f "$1" ] # multiple args or a file
then
    for FILE in "$@"
    do
    ORIG="$FILE.orig"
    echo "$FILE" 1>&2
    echo "diff -ub $ORIG $FILE"
    /usr/bin/diff -ub $ORIG $FILE
    done
else
    if [ "$#" -eq 0 ]
    then    APATH="."  # no arg: recursively all origs
    else    APATH="$1" # or one arg: recursively all origs
    fi
    find "$APATH" -name '*.orig' -print | sort \
         while read FILE
    do
    NEW="`dirname $FILE`/`basename $FILE .orig`"
    echo "$NEW" 1>&2
    echo "diff -ub $ORIG $FILE"
    /usr/bin/diff -ub $FILE $NEW
    done
fi