#!/bin/sh
# $Id: dist-tar,v 1.11 2018/12/24 21:15:47 friedman Exp $

LC_COLLATE=C
export LC_COLLATE

cmdp() { type "$@" > /dev/null 2>&1; }
case ${FIND-nil} in nil ) if cmdp gfind; then FIND=gfind; fi ;; esac
case ${TAR-nil}  in nil ) if cmdp gtar;  then TAR=gtar;   fi ;; esac
case ${SORT-nil} in nil ) if cmdp gsort; then SORT=gsort; fi ;; esac

gnup() { "$1" --version 2>&1 | grep "GNU" > /dev/null; }
if gnup ${TAR-tar}; then
    gnutar=t
    if gnup ${FIND-find} && gnup ${SORT-sort}; then
        FPRINT=print0
        SORTOPT="$SORTOPT --zero-terminated"
        TAROPT="$TAROPT --null"
    fi
fi

case $1 in
    -gzip | -bzip2 | -lzma | -xz ) DIST_TAR_ZIP=${1#-} ; shift ;;
esac

case ${DIST_TAR_ZIP-gzip} in
    gzip  ) zip=gzip  z=gz   zargs='-9' ;;
    bzip2 ) zip=bzip2 z=bz2  zargs='-9' ;;
    lzma  ) zip=lzma  z=lzma zargs='-9 --extreme --threads=0' ;;
    xz    ) zip=xz    z=xz   zargs='-9 --extreme --threads=0' ;;
    *     ) echo "dist-tar: $DIST_TAR_ZIP: unknown compression method" 1>&2
            exit 1 ;;
esac

for dir in "$@" ; do
    # Protect against accidental trailing slash, i.e. if someone does
    # dist-tar foo/, don't create foo/.tar.gz only to delete foo after.
    dir=${dir%/}
    { case $gnutar in
          t ) echo "dist-tar: (gnu) packing $dir.tar.$z"
              ${FIND-find} "$dir" -${FPRINT-print} \
                  | ${SORT-sort} $SORTOPT \
                  | ${TAR-tar} $TAROPT --no-recursion -T - -cvf - \
                  | $zip $zargs > "$dir.tar.$z" ;;

          * ) echo "dist-tar: packing $dir.tar.$z"
              ${TAR-tar} $TAROPT -cvf - "$dir" \
                  | $zip $zargs > "$dir.tar.$z" ;;
      esac
    } && touch -r "$dir" "$dir.tar.$z" \
      && rm -rf "$dir"
done

# eof