rpm/scripts/brp-compress

#!/bin/sh

# If using normal root, avoid changing anything.
if [ -z "$RPM_BUILD_ROOT" ] || [ "$RPM_BUILD_ROOT" = "/" ]; then
	exit 0
fi

PREFIX=${1:-/usr}

cd "$RPM_BUILD_ROOT"

# Compress man pages
COMPRESS=${COMPRESS:-gzip -9 -n}
COMPRESS_EXT=${COMPRESS_EXT:-.gz}

for d in .${PREFIX}/man/man* .${PREFIX}/man/*/man* .${PREFIX}/info \
    .${PREFIX}/share/man/man* .${PREFIX}/share/man/*/man* \
    .${PREFIX}/share/info .${PREFIX}/kerberos/man \
    .${PREFIX}/X11R6/man/man* .${PREFIX}/lib/perl5/man/man* \
    .${PREFIX}/share/doc/*/man/man* .${PREFIX}/lib/*/man/man* \
    .${PREFIX}/share/fish/man/man*
do
    [ -d $d ] || continue
    find $d -type f ! -name dir -print0 |
    while IFS= read -r -d '' f; do
		[ -f "$f" ] || continue

    case "$f" in
     *.gz|*.Z)    gunzip  -f "$f"; b=`echo "$f" | sed -e 's/\.\(gz\|Z\)$//'`;;
     *.bz2)       bunzip2 -f "$f"; b=`echo "$f" | sed -e 's/\.bz2$//'`;;
     *.xz|*.lzma) unxz    -f "$f"; b=`echo "$f" | sed -e 's/\.\(xz\|lzma\)$//'`;;
     *.zst|*.zstd) unzstd -f --rm $f; b=`echo "$f" | sed -e 's/\.\(zst\|zstd\)$//'`;;
     *) b="$f";;
    esac

    $COMPRESS "$b" </dev/null 2>/dev/null || {
		inode=`ls -i "$b" | awk '{ print $1 }'`
		others="`find $d -type f -inum $inode`"
		if [ -n "$others" ]; then
		for afile in $others ; do
		    [ "$afile" != "$b" ] && rm -f $afile
		done
		$COMPRESS -f "$b"
		for afile in $others ; do
		    [ "$afile" != "$b" ] && ln "$b$COMPRESS_EXT" "$afile$COMPRESS_EXT"
		done
		else
		$COMPRESS -f "$b"
		fi
    }
    done

    find $d -type l --print0 |
    while IFS= read -r -d '' f; do
    l=`ls -l $f | sed -e 's/.* -> //' -e 's/\.\(gz\|Z\|bz2\|xz\|lzma\|zst\|zstd\)$//'`
    rm -f $f
    b=`echo $f | sed -e 's/\.\(gz\|Z\|bz2\|xz\|lzma\|zst\|zstd\)$//'`
    ln -sf "$l$COMPRESS_EXT" "$b$COMPRESS_EXT"
    done
done