1#!/usr/bin/env bash
2# SPDX-License-Identifier: GPL-2.0
3# Manipulate options in a .config file from the command line
4
5myname=${0##*/}
6
7# If no prefix forced, use the default CONFIG_
8CONFIG_="${CONFIG_-CONFIG_}"
9
10# We use an uncommon delimiter for sed substitutions
11SED_DELIM=$(echo -en "\001")
12
13usage() {
14	cat >&2 <<EOL
15Manipulate options in a .config file from the command line.
16Usage:
17$myname options command ...
18commands:
19	--enable|-e option   Enable option
20	--disable|-d option  Disable option
21	--module|-m option   Turn option into a module
22	--set-str option string
23	                     Set option to "string"
24	--set-val option value
25	                     Set option to value
26	--undefine|-u option Undefine option
27	--state|-s option    Print state of option (n,y,m,undef)
28
29	--enable-after|-E beforeopt option
30                             Enable option directly after other option
31	--disable-after|-D beforeopt option
32                             Disable option directly after other option
33	--module-after|-M beforeopt option
34                             Turn option into module directly after other option
35
36	commands can be repeated multiple times
37
38options:
39	--file config-file   .config file to change (default .config)
40	--keep-case|-k       Keep next symbols' case (dont' upper-case it)
41
42$myname doesn't check the validity of the .config file. This is done at next
43make time.
44
45By default, $myname will upper-case the given symbol. Use --keep-case to keep
46the case of all following symbols unchanged.
47
48$myname uses 'CONFIG_' as the default symbol prefix. Set the environment
49variable CONFIG_ to the prefix to use. Eg.: CONFIG_="FOO_" $myname ...
50EOL
51	exit 1
52}
53
54checkarg() {
55	ARG="$1"
56	if [ "$ARG" = "" ] ; then
57		usage
58	fi
59	case "$ARG" in
60	${CONFIG_}*)
61		ARG="${ARG/${CONFIG_}/}"
62		;;
63	esac
64	if [ "$MUNGE_CASE" = "yes" ] ; then
65		ARG="`echo $ARG | tr a-z A-Z`"
66	fi
67}
68
69txt_append() {
70	local anchor="$1"
71	local insert="$2"
72	local infile="$3"
73	local tmpfile="$infile.swp"
74
75	# sed append cmd: 'a\' + newline + text + newline
76	cmd="$(printf "a\\%b$insert" "\n")"
77
78	sed -e "/$anchor/$cmd" "$infile" >"$tmpfile"
79	# replace original file with the edited one
80	mv "$tmpfile" "$infile"
81}
82
83txt_subst() {
84	local before="$1"
85	local after="$2"
86	local infile="$3"
87	local tmpfile="$infile.swp"
88
89	sed -e "s$SED_DELIM$before$SED_DELIM$after$SED_DELIM" "$infile" >"$tmpfile"
90	# replace original file with the edited one
91	mv "$tmpfile" "$infile"
92}
93
94txt_delete() {
95	local text="$1"
96	local infile="$2"
97	local tmpfile="$infile.swp"
98
99	sed -e "/$text/d" "$infile" >"$tmpfile"
100	# replace original file with the edited one
101	mv "$tmpfile" "$infile"
102}
103
104set_var() {
105	local name=$1 new=$2 before=$3
106
107	name_re="^($name=|# $name is not set)"
108	before_re="^($before=|# $before is not set)"
109	if test -n "$before" && grep -Eq "$before_re" "$FN"; then
110		txt_append "^$before=" "$new" "$FN"
111		txt_append "^# $before is not set" "$new" "$FN"
112	elif grep -Eq "$name_re" "$FN"; then
113		txt_subst "^$name=.*" "$new" "$FN"
114		txt_subst "^# $name is not set" "$new" "$FN"
115	else
116		echo "$new" >>"$FN"
117	fi
118}
119
120undef_var() {
121	local name=$1
122
123	txt_delete "^$name=" "$FN"
124	txt_delete "^# $name is not set" "$FN"
125}
126
127if [ "$1" = "--file" ]; then
128	FN="$2"
129	if [ "$FN" = "" ] ; then
130		usage
131	fi
132	shift 2
133else
134	FN=.config
135fi
136
137if [ "$1" = "" ] ; then
138	usage
139fi
140
141MUNGE_CASE=yes
142while [ "$1" != "" ] ; do
143	CMD="$1"
144	shift
145	case "$CMD" in
146	--keep-case|-k)
147		MUNGE_CASE=no
148		continue
149		;;
150	--refresh)
151		;;
152	--*-after|-E|-D|-M)
153		checkarg "$1"
154		A=$ARG
155		checkarg "$2"
156		B=$ARG
157		shift 2
158		;;
159	-*)
160		checkarg "$1"
161		shift
162		;;
163	esac
164	case "$CMD" in
165	--enable|-e)
166		set_var "${CONFIG_}$ARG" "${CONFIG_}$ARG=y"
167		;;
168
169	--disable|-d)
170		set_var "${CONFIG_}$ARG" "# ${CONFIG_}$ARG is not set"
171		;;
172
173	--module|-m)
174		set_var "${CONFIG_}$ARG" "${CONFIG_}$ARG=m"
175		;;
176
177	--set-str)
178		# sed swallows one level of escaping, so we need double-escaping
179		set_var "${CONFIG_}$ARG" "${CONFIG_}$ARG=\"${1//\"/\\\\\"}\""
180		shift
181		;;
182
183	--set-val)
184		set_var "${CONFIG_}$ARG" "${CONFIG_}$ARG=$1"
185		shift
186		;;
187	--undefine|-u)
188		undef_var "${CONFIG_}$ARG"
189		;;
190
191	--state|-s)
192		if grep -q "# ${CONFIG_}$ARG is not set" $FN ; then
193			echo n
194		else
195			V="$(grep "^${CONFIG_}$ARG=" $FN)"
196			if [ $? != 0 ] ; then
197				echo undef
198			else
199				V="${V/#${CONFIG_}$ARG=/}"
200				V="${V/#\"/}"
201				V="${V/%\"/}"
202				V="${V//\\\"/\"}"
203				echo "${V}"
204			fi
205		fi
206		;;
207
208	--enable-after|-E)
209		set_var "${CONFIG_}$B" "${CONFIG_}$B=y" "${CONFIG_}$A"
210		;;
211
212	--disable-after|-D)
213		set_var "${CONFIG_}$B" "# ${CONFIG_}$B is not set" "${CONFIG_}$A"
214		;;
215
216	--module-after|-M)
217		set_var "${CONFIG_}$B" "${CONFIG_}$B=m" "${CONFIG_}$A"
218		;;
219
220	# undocumented because it ignores --file (fixme)
221	--refresh)
222		yes "" | make oldconfig
223		;;
224
225	*)
226		echo "bad command: $CMD" >&2
227		usage
228		;;
229	esac
230done
231