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