/usr/bin/dglob is in debian-goodies 0.69.1.
This file is owned by root:root, with mode 0o755.
The actual contents of the file can be viewed below.
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74  | #!/bin/sh -e
# dglob - Expand package names matching a pattern and conditions
# Copyright (C) 2001 Matt Zimmerman <mdz@debian.org>
# This program is free software; you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation; either version 2, or (at your option)
# any later version.
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU General Public License for more details.
# You should have received a copy of the GNU General Public License
# along with this program; if not, write to the Free Software
# Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA
# 02111-1307, USA.
#
ARGS=`getopt -o af0reinXv -n dglob -- "$@"`
eval set -- "$ARGS"
filter="grep-dctrl -FStatus ' installed'"
expand="cat"
grep_dctrl_options=""
all="no"
dglob_not() {
# List packages that are available but not installed
    { dglob $* ; dglob -a $* ; } | sort | uniq -u ;
}
while true; do
    case "$1" in
        -n) shift; ARGS=`echo $@ | sed -e 's/--/ /'`; dglob_not $ARGS; exit 0;;
        -a) filter="cat" ; all="yes" ; shift ;;
        -0) SEP=0 ; shift ;;
        -r|-e|-i|-X|-v) grep_dctrl_options="$grep_dctrl_options $1"; shift ;;
        -f) expand="xargs dpkg --listfiles | perl -nl${SEP}e 'print if -f'"
            if [ "$all" = "yes" ] ; then
                if [ -n "`which apt-file`" ]   ; then
# if we have apt-file use it instead
                    expand="while read pack; do apt-file show \$pack; done | perl -ple 's/^.*?: //'"
                else
                    echo "WARN: You requested information on files of all packages," >&2
                    echo "WARN: however, since the 'apt-file' package is not available, this" >&2
                    echo "WARN: information can only be provided for those packages currently installed." >&2
                fi
            fi
            shift
            ;;
        --) shift ; break ;;
    esac
done
# Does the package exist?
if [ "$all" = "no" ] ; then
    packages=`eval $filter /var/lib/dpkg/status | grep-dctrl -PnsPackage $grep_dctrl_options "$1"`
    if [ -z "$packages" ] ; then
    	exit 1
    fi
    eval $filter /var/lib/dpkg/status | grep-dctrl -PnsPackage $grep_dctrl_options "$1" | grep -v ^$ |
    (eval $expand)
else
    # Use grep-available as the status file does not include all available
    # packages
    grep-aptavail -PnsPackage $grep_dctrl_options "$1" | grep -v ^$ |
    (eval $expand)
fi
 |