--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/bash-completion.sh	Sat Oct 26 23:01:03 2019 +0200
@@ -0,0 +1,72 @@
+# Relational pipes
+# Copyright © 2019 František Kučera (Frantovo.cz, GlobalCode.info)
+#
+# 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, version 3 of the License.
+#
+# 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, see <http://www.gnu.org/licenses/>.
+
+_relpipe_in_filesystem_completion() {
+	local w0 w1 w2
+
+	COMPREPLY=()
+	w0=${COMP_WORDS[COMP_CWORD]}
+	w1=${COMP_WORDS[COMP_CWORD-1]}
+	w2=${COMP_WORDS[COMP_CWORD-2]}
+
+
+	FILE_FIELDS=(
+		"path"
+		"name"
+		"size"
+		"path_absolute"
+		"path_canonical"
+		"type"
+		"symlink_target_type"
+		"symlink_target"
+		"owner"
+		"group"
+		"content"
+	)
+
+	XATTR_FIELDS=(
+		"mime_type"
+		"charset"
+		"creator"
+		"xdg.comment"
+		"xdg.origin.url"
+		"xdg.origin.email.subject"
+		"xdg.language"
+		"xdg.publisher"
+		"dublincore.title"
+		"dublincore.creator"
+		"dublincore.rights"
+	)
+
+
+	if   [[ "$w1" == "--relation"      && "x$w0" == "x" ]];    then COMPREPLY=("''")
+	elif [[ "$w1" == "--as"            && "x$w0" == "x" ]];    then COMPREPLY=("''")
+	elif [[ "$w1" == "--option"        && "x$w0" == "x" ]];    then COMPREPLY=("''")
+	elif [[ "$w2" == "--option"        && "x$w0" == "x" ]];    then COMPREPLY=("''")
+	elif [[ "$w1" == "--file"                           ]];    then COMPREPLY=($(compgen -W "${FILE_FIELDS[*]}"  -- "$w0"))
+	elif [[ "$w1" == "--xattr"                          ]];    then COMPREPLY=($(compgen -W "${XATTR_FIELDS[*]}" -- "$w0"))
+	else
+		OPTIONS=(
+			"--relation"
+			"--file"
+			"--xattr"
+			"--as"
+			"--option"
+		)
+		COMPREPLY=($(compgen -W "${OPTIONS[*]}" -- "$w0"))
+	fi
+}
+
+complete -F _relpipe_in_filesystem_completion relpipe-in-filesystem