xref: /freebsd/usr.sbin/bsdconfig/share/common.subr (revision 7cd2dcf07629713e5a3d60472cfe4701b705a167)
1if [ ! "$_COMMON_SUBR" ]; then _COMMON_SUBR=1
2#
3# Copyright (c) 2012 Ron McDowell
4# Copyright (c) 2012 Devin Teske
5# All rights reserved.
6#
7# Redistribution and use in source and binary forms, with or without
8# modification, are permitted provided that the following conditions
9# are met:
10# 1. Redistributions of source code must retain the above copyright
11#    notice, this list of conditions and the following disclaimer.
12# 2. Redistributions in binary form must reproduce the above copyright
13#    notice, this list of conditions and the following disclaimer in the
14#    documentation and/or other materials provided with the distribution.
15#
16# THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
17# ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
18# IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
19# ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
20# FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
21# DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
22# OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
23# HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
24# LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
25# OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
26# SUCH DAMAGE.
27#
28# $FreeBSD$
29#
30############################################################ GLOBALS
31
32#
33# Program name
34#
35pgm="${0##*/}"
36
37#
38# Program arguments
39#
40ARGC="$#"
41ARGV="$@"
42
43#
44# Global exit status variables
45#
46SUCCESS=0
47FAILURE=1
48
49############################################################ FUNCTIONS
50
51#
52# This is an empty function by default, to use it, copy
53# /usr/share/examples/bsdconfig/bsdconfigrc to $HOME/.bsdconfigrc
54#
55f_dprintf()
56{
57	: this page intentionally left blank
58}
59
60# f_err $fmt [ $opts ... ]
61#
62# Print a message to stderr (fd=2).
63#
64f_err()
65{
66	printf "$@" >&2
67}
68
69# f_quietly $command [ $arguments ... ]
70#
71# Run a command quietly (quell any output to stdout or stderr)
72#
73f_quietly()
74{
75	"$@" > /dev/null 2>&1
76}
77
78# f_have $anything ...
79#
80# A wrapper to the `type' built-in. Returns true if argument is a valid shell
81# built-in, keyword, or externally-tracked binary, otherwise false.
82#
83f_have()
84{
85	f_quietly type "$@"
86}
87
88# f_die [ $status [ $fmt [ $opts ... ]]]
89#
90# Abruptly terminate due to an error optionally displaying a message in a
91# dialog box using printf(1) syntax.
92#
93f_die()
94{
95	local status=$FAILURE
96
97	# If there is at least one argument, take it as the status
98	if [ $# -gt 0 ]; then
99		status=$1
100		shift 1 # status
101	fi
102
103	# If there are still arguments left, pass them to f_show_msg
104	[ $# -gt 0 ] && f_show_msg "$@"
105
106	# Optionally call f_clean_up() function if it exists
107	f_have f_clean_up && f_clean_up
108
109	exit $status
110}
111
112# f_interrupt
113#
114# Interrupt handler.
115#
116f_interrupt()
117{
118	exec 2>&1 # fix sh(1) bug where stderr gets lost within async-trap
119	f_die
120}
121
122# f_show_msg $fmt [ $opts ... ]
123#
124# Display a message in a dialog box using printf(1) syntax.
125#
126f_show_msg()
127{
128	local msg
129	msg=$( printf "$@" )
130
131	#
132	# Use f_dialog_msgbox from dialog.subr if possible, otherwise fall
133	# back to dialog(1) (without options, making it obvious when using
134	# un-aided system dialog).
135	#
136	if f_have f_dialog_msgbox; then
137		f_dialog_msgbox "$msg"
138	else
139		dialog --msgbox "$msg" 0 0
140	fi
141}
142
143# f_show_help $file
144#
145# Display a language help-file. Automatically takes $LANG and $LC_ALL into
146# consideration when displaying $file (suffix ".$LC_ALL" or ".$LANG" will
147# automatically be added prior to loading the language help-file).
148#
149# If a language has been requested by setting either $LANG or $LC_ALL in the
150# environment and the language-specific help-file does not exist we will fall
151# back to $file without-suffix.
152#
153# If the language help-file does not exist, an error is displayed instead.
154#
155f_show_help()
156{
157	local file="$1"
158	local lang="${LANG:-$LC_ALL}"
159
160	[ -f "$file.$lang" ] && file="$file.$lang"
161
162	#
163	# Use f_dialog_textbox from dialog.subr if possible, otherwise fall
164	# back to dialog(1) (without options, making it obvious when using
165	# un-aided system dialog).
166	#
167	if f_have f_dialog_textbox; then
168		f_dialog_textbox "$file"
169	else
170		dialog --msgbox "$( cat "$file" 2>&1 )" 0 0
171	fi
172}
173
174# f_include $file
175#
176# Include a shell subroutine file.
177#
178# If the subroutine file exists but returns error status during loading, exit
179# is called and execution is prematurely terminated with the same error status.
180#
181f_include()
182{
183	local file="$1"
184	. "$file" || exit $?
185}
186
187# f_include_lang $file
188#
189# Include a language file. Automatically takes $LANG and $LC_ALL into
190# consideration when including $file (suffix ".$LC_ALL" or ".$LANG" will
191# automatically by added prior to loading the language file).
192#
193# No error is produced if (a) a language has been requested (by setting either
194# $LANG or $LC_ALL in the environment) and (b) the language file does not
195# exist -- in which case we will fall back to loading $file without-suffix.
196#
197# If the language file exists but returns error status during loading, exit
198# is called and execution is prematurely terminated with the same error status.
199#
200f_include_lang()
201{
202	local file="$1"
203	local lang="${LANG:-$LC_ALL}"
204
205	f_dprintf "lang=[$lang]"
206	if [ -f "$file.$lang" ]; then
207		. "$file.$lang" || exit $?
208	else
209		. "$file" || exit $?
210	fi
211}
212
213# f_usage $file [ $key1 $value1 ... ]
214#
215# Display USAGE file with optional pre-processor macro definitions. The first
216# argument is the template file containing the usage text to be displayed. If
217# $LANG or $LC_ALL (in order of preference, respectively) is set, ".encoding"
218# will automatically be appended as a suffix to the provided $file pathname.
219#
220# When processing $file, output begins at the first line containing that is
221# (a) not a comment, (b) not empty, and (c) is not pure-whitespace. All lines
222# appearing after this first-line are output, including (a) comments (b) empty
223# lines, and (c) lines that are purely whitespace-only.
224#
225# If additional arguments appear after $file, substitutions are made while
226# printing the contents of the USAGE file. The pre-processor macro syntax is in
227# the style of autoconf(1), for example:
228#
229# 	f_usage $file "FOO" "BAR"
230#
231# Will cause instances of "@FOO@" appearing in $file to be replaced with the
232# text "BAR" before bering printed to the screen.
233#
234# This function is a two-parter. Below is the awk(1) portion of the function,
235# afterward is the sh(1) function which utilizes the below awk script.
236#
237f_usage_awk='
238BEGIN { found = 0 }
239{
240	if ( !found && $0 ~ /^[[:space:]]*($|#)/ ) next
241	found = 1
242	print
243}
244'
245f_usage()
246{
247	local file="$1"
248	local lang="${LANG:-$LC_ALL}"
249
250	f_dprintf "lang=[$lang]"
251
252	shift 1 # file
253
254	local usage
255	if [ -f "$file.$lang" ]; then
256		usage=$( awk "$f_usage_awk" "$file.$lang" ) || exit $FAILURE
257	else
258		usage=$( awk "$f_usage_awk" "$file" ) || exit $FAILURE
259	fi
260
261	while [ $# -gt 0 ]; do
262		local key="$1"
263		export value="$2"
264		usage=$( echo "$usage" | awk \
265			"{ gsub(/@$key@/, ENVIRON[\"value\"]); print }" )
266		shift 2
267	done
268
269	f_err "%s\n" "$usage"
270
271	exit $FAILURE
272}
273
274# f_index_menu_selection $file $pgm
275#
276# Process $file looking for $menu_selection values that correspond to $pgm.
277# This function is for internationalization (i18n) mapping of the on-disk
278# scriptname ($pgm) into the localized language (given language-specific
279# $file). If $LANG or $LC_ALL (in orderder of preference, respectively) is set,
280# ".encoding" will automatically be appended as a suffix to the provided $file
281# pathname.
282#
283# If, within $file, multiple $menu_selection values map to $pgm, only the first
284# one will be returned. If no mapping can be made, the NULL string is returned.
285#
286# If $file does not exist, error status is returned along with the NULL string.
287#
288# This function is a two-parter. Below is the awk(1) portion of the function,
289# afterward is the sh(1) function which utilizes the below awk script.
290#
291f_index_menusel_awk='
292# Variables that should be defined on the invocation line:
293# 	-v pgm="program_name"
294#
295( $0 ~ "^menu_selection=.*\\|" pgm "\"" ) {
296	sub(/\|.*/, "")
297	sub(/^menu_selection="/, "")
298	print
299	exit
300}
301'
302f_index_menu_selection()
303{
304	local file="$1" pgm="$2"
305	local lang="${LANG:-$LC_ALL}"
306
307	f_dprintf "lang=[$lang]"
308
309	if [ -f "$file.$lang" ]; then
310		awk -v pgm="$pgm" "$f_index_menusel_awk" "$file.$lang" ||
311			exit $FAILURE
312	elif [ -f "$file" ]; then
313		awk -v pgm="$pgm" "$f_index_menusel_awk" "$file" ||
314			exit $FAILURE
315	else
316		return $FAILURE
317	fi
318}
319
320############################################################ MAIN
321
322#
323# Trap signals so we can recover gracefully
324#
325trap 'f_interrupt' SIGINT
326trap 'f_die' SIGTERM SIGPIPE SIGXCPU SIGXFSZ \
327             SIGFPE SIGTRAP SIGABRT SIGSEGV
328trap '' SIGALRM SIGPROF SIGUSR1 SIGUSR2 SIGHUP SIGVTALRM
329
330fi # ! $_COMMON_SUBR
331