xref: /freebsd/usr.sbin/bsdconfig/share/common.subr (revision ca987d4641cdcd7f27e153db17c5bf064934faf5)
1if [ ! "$_COMMON_SUBR" ]; then _COMMON_SUBR=1
2#
3# Copyright (c) 2012 Ron McDowell
4# Copyright (c) 2012-2016 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############################################################ CONFIGURATION
31
32#
33# Default file descriptors to link to stdout/stderr for passthru allowing
34# redirection within a sub-shell to bypass directly to the terminal.
35#
36: ${TERMINAL_STDOUT_PASSTHRU:=3}
37: ${TERMINAL_STDERR_PASSTHRU:=4}
38
39############################################################ GLOBALS
40
41#
42# Program name
43#
44pgm="${0##*/}"
45
46#
47# Program arguments
48#
49ARGC="$#"
50ARGV="$@"
51
52#
53# Global exit status variables
54#
55SUCCESS=0
56FAILURE=1
57
58#
59# Operating environment details
60#
61export UNAME_S="$( uname -s )" # Operating System (i.e. FreeBSD)
62export UNAME_P="$( uname -p )" # Processor Architecture (i.e. i386)
63export UNAME_M="$( uname -m )" # Machine platform (i.e. i386)
64export UNAME_R="$( uname -r )" # Release Level (i.e. X.Y-RELEASE)
65
66#
67# Default behavior is to call f_debug_init() automatically when loaded.
68#
69: ${DEBUG_SELF_INITIALIZE=1}
70
71#
72# Default behavior of f_debug_init() is to truncate $debugFile (set to NULL to
73# disable truncating the debug file when initializing). To get child processes
74# to append to the same log file, export this variarable (with a NULL value)
75# and also export debugFile with the desired value.
76#
77: ${DEBUG_INITIALIZE_FILE=1}
78
79#
80# Define standard optstring arguments that should be supported by all programs
81# using this include (unless DEBUG_SELF_INITIALIZE is set to NULL to prevent
82# f_debug_init() from autamatically processing "$@" for the below arguments):
83#
84# 	d	Sets $debug to 1
85# 	D:	Sets $debugFile to $OPTARG
86#
87GETOPTS_STDARGS="dD:"
88
89#
90# The getopts builtin will return 1 either when the end of "$@" or the first
91# invalid flag is reached. This makes it impossible to determine if you've
92# processed all the arguments or simply have hit an invalid flag. In the cases
93# where we want to tolerate invalid flags (f_debug_init() for example), the
94# following variable can be appended to your optstring argument to getopts,
95# preventing it from prematurely returning 1 before the end of the arguments.
96#
97# NOTE: This assumes that all unknown flags are argument-less.
98#
99GETOPTS_ALLFLAGS="abcdefghijklmnopqrstuvwxyz"
100GETOPTS_ALLFLAGS="${GETOPTS_ALLFLAGS}ABCDEFGHIJKLMNOPQRSTUVWXYZ"
101GETOPTS_ALLFLAGS="${GETOPTS_ALLFLAGS}0123456789"
102
103#
104# When we get included, f_debug_init() will fire (unless $DEBUG_SELF_INITIALIZE
105# is set to disable automatic initialization) and process "$@" for a few global
106# options such as `-d' and/or `-D file'. However, if your program takes custom
107# flags that take arguments, this automatic processing may fail unexpectedly.
108#
109# The solution to this problem is to pre-define (before including this file)
110# the following variable (which defaults to NULL) to indicate that there are
111# extra flags that should be considered when performing automatic processing of
112# globally persistent flags.
113#
114: ${GETOPTS_EXTRA:=}
115
116############################################################ FUNCTIONS
117
118# f_dprintf $format [$arguments ...]
119#
120# Sensible debug function. Override in ~/.bsdconfigrc if desired.
121# See /usr/share/examples/bsdconfig/bsdconfigrc for example.
122#
123# If $debug is set and non-NULL, prints DEBUG info using printf(1) syntax:
124# 	+ To $debugFile, if set and non-NULL
125# 	+ To standard output if $debugFile is either NULL or unset
126# 	+ To both if $debugFile begins with a single plus-sign (`+')
127#
128f_dprintf()
129{
130	[ "$debug" ] || return $SUCCESS
131	local fmt="$1"; shift
132	case "$debugFile" in ""|+*)
133	printf "DEBUG: $fmt${fmt:+\n}" "$@" >&${TERMINAL_STDOUT_PASSTHRU:-1}
134	esac
135	[ "${debugFile#+}" ] &&
136		printf "DEBUG: $fmt${fmt:+\n}" "$@" >> "${debugFile#+}"
137	return $SUCCESS
138}
139
140# f_debug_init
141#
142# Initialize debugging. Truncates $debugFile to zero bytes if set.
143#
144f_debug_init()
145{
146	#
147	# Process stored command-line arguments
148	#
149	set -- $ARGV
150	local OPTIND OPTARG flag
151	f_dprintf "f_debug_init: ARGV=[%s] GETOPTS_STDARGS=[%s]" \
152	          "$ARGV" "$GETOPTS_STDARGS"
153	while getopts "$GETOPTS_STDARGS$GETOPTS_EXTRA$GETOPTS_ALLFLAGS" flag \
154	> /dev/null; do
155		case "$flag" in
156		d) debug=1 ;;
157		D) debugFile="$OPTARG" ;;
158		esac
159	done
160	shift $(( $OPTIND - 1 ))
161	f_dprintf "f_debug_init: debug=[%s] debugFile=[%s]" \
162	          "$debug" "$debugFile"
163
164	#
165	# Automagically enable debugging if debugFile is set (and non-NULL)
166	#
167	[ "$debugFile" ] && { [ "${debug+set}" ] || debug=1; }
168
169	#
170	# Make debugging persistent if set
171	#
172	[ "$debug" ] && export debug
173	[ "$debugFile" ] && export debugFile
174
175	#
176	# Truncate debug file unless requested otherwise. Note that we will
177	# trim a leading plus (`+') from the value of debugFile to support
178	# persistent meaning that f_dprintf() should print both to standard
179	# output and $debugFile (minus the leading plus, of course).
180	#
181	local _debug_file="${debugFile#+}"
182	if [ "$_debug_file" -a "$DEBUG_INITIALIZE_FILE" ]; then
183		if ( umask 022 && :> "$_debug_file" ); then
184			f_dprintf "Successfully initialized debugFile \`%s'" \
185			          "$_debug_file"
186			f_isset debug || debug=1 # turn debugging on if not set
187		else
188			unset debugFile
189			f_dprintf "Unable to initialize debugFile \`%s'" \
190			          "$_debug_file"
191		fi
192	fi
193}
194
195# f_err $format [$arguments ...]
196#
197# Print a message to stderr (fd=2).
198#
199f_err()
200{
201	printf "$@" >&2
202}
203
204# f_quietly $command [$arguments ...]
205#
206# Run a command quietly (quell any output to stdout or stderr)
207#
208f_quietly()
209{
210	"$@" > /dev/null 2>&1
211}
212
213# f_have $anything ...
214#
215# A wrapper to the `type' built-in. Returns true if argument is a valid shell
216# built-in, keyword, or externally-tracked binary, otherwise false.
217#
218f_have()
219{
220	f_quietly type "$@"
221}
222
223# setvar $var_to_set [$value]
224#
225# Implement setvar for shells unlike FreeBSD sh(1).
226#
227if ! f_have setvar; then
228setvar()
229{
230	[ $# -gt 0 ] || return $SUCCESS
231	local __setvar_var_to_set="$1" __setvar_right="$2" __setvar_left=
232	case $# in
233	1) unset "$__setvar_var_to_set"
234	   return $? ;;
235	2) : fall through ;;
236	*) f_err "setvar: too many arguments\n"
237	   return $FAILURE
238	esac
239	case "$__setvar_var_to_set" in *[!0-9A-Za-z_]*)
240		f_err "setvar: %s: bad variable name\n" "$__setvar_var_to_set"
241		return 2
242	esac
243	while case "$__setvar_r" in *\'*) : ;; *) false ; esac
244	do
245		__setvar_left="$__setvar_left${__setvar_right%%\'*}'\\''"
246		__setvar_right="${__setvar_right#*\'}"
247	done
248	__setvar_left="$__setvar_left${__setvar_right#*\'}"
249	eval "$__setvar_var_to_set='$__setvar_left'"
250}
251fi
252
253# f_which $anything [$var_to_set]
254#
255# A fast built-in replacement for syntaxes such as foo=$( which bar ). In a
256# comparison of 10,000 runs of this function versus which, this function
257# completed in under 3 seconds, while `which' took almost a full minute.
258#
259# If $var_to_set is missing or NULL, output is (like which) to standard out.
260# Returns success if a match was found, failure otherwise.
261#
262f_which()
263{
264	local __name="$1" __var_to_set="$2"
265	case "$__name" in */*|'') return $FAILURE; esac
266	local __p __exec IFS=":" __found=
267	for __p in $PATH; do
268		__exec="$__p/$__name"
269		[ -f "$__exec" -a -x "$__exec" ] && __found=1 break
270	done
271	if [ "$__found" ]; then
272		if [ "$__var_to_set" ]; then
273			setvar "$__var_to_set" "$__exec"
274		else
275			echo "$__exec"
276		fi
277		return $SUCCESS
278	fi
279	return $FAILURE
280}
281
282# f_getvar $var_to_get [$var_to_set]
283#
284# Utility function designed to go along with the already-builtin setvar.
285# Allows clean variable name indirection without forking or sub-shells.
286#
287# Returns error status if the requested variable ($var_to_get) is not set.
288#
289# If $var_to_set is missing or NULL, the value of $var_to_get is printed to
290# standard output for capturing in a sub-shell (which is less-recommended
291# because of performance degredation; for example, when called in a loop).
292#
293f_getvar()
294{
295	local __var_to_get="$1" __var_to_set="$2"
296	[ "$__var_to_set" ] || local value
297	eval [ \"\${$__var_to_get+set}\" ]
298	local __retval=$?
299	eval ${__var_to_set:-value}=\"\${$__var_to_get}\"
300	eval f_dprintf '"f_getvar: var=[%s] value=[%s] r=%u"' \
301		\"\$__var_to_get\" \"\$${__var_to_set:-value}\" \$__retval
302	[ "$__var_to_set" ] || { [ "$value" ] && echo "$value"; }
303	return $__retval
304}
305
306# f_isset $var
307#
308# Check if variable $var is set. Returns success if variable is set, otherwise
309# returns failure.
310#
311f_isset()
312{
313	eval [ \"\${${1%%[$IFS]*}+set}\" ]
314}
315
316# f_die [$status [$format [$arguments ...]]]
317#
318# Abruptly terminate due to an error optionally displaying a message in a
319# dialog box using printf(1) syntax.
320#
321f_die()
322{
323	local status=$FAILURE
324
325	# If there is at least one argument, take it as the status
326	if [ $# -gt 0 ]; then
327		status=$1
328		shift 1 # status
329	fi
330
331	# If there are still arguments left, pass them to f_show_msg
332	[ $# -gt 0 ] && f_show_msg "$@"
333
334	# Optionally call f_clean_up() function if it exists
335	f_have f_clean_up && f_clean_up
336
337	exit $status
338}
339
340# f_interrupt
341#
342# Interrupt handler.
343#
344f_interrupt()
345{
346	exec 2>&1 # fix sh(1) bug where stderr gets lost within async-trap
347	f_die
348}
349
350# f_show_info $format [$arguments ...]
351#
352# Display a message in a dialog infobox using printf(1) syntax.
353#
354f_show_info()
355{
356	local msg
357	msg=$( printf "$@" )
358
359	#
360	# Use f_dialog_infobox from dialog.subr if possible, otherwise fall
361	# back to dialog(1) (without options, making it obvious when using
362	# un-aided system dialog).
363	#
364	if f_have f_dialog_info; then
365		f_dialog_info "$msg"
366	else
367		dialog --infobox "$msg" 0 0
368	fi
369}
370
371# f_show_msg $format [$arguments ...]
372#
373# Display a message in a dialog box using printf(1) syntax.
374#
375f_show_msg()
376{
377	local msg
378	msg=$( printf "$@" )
379
380	#
381	# Use f_dialog_msgbox from dialog.subr if possible, otherwise fall
382	# back to dialog(1) (without options, making it obvious when using
383	# un-aided system dialog).
384	#
385	if f_have f_dialog_msgbox; then
386		f_dialog_msgbox "$msg"
387	else
388		dialog --msgbox "$msg" 0 0
389	fi
390}
391
392# f_show_err $format [$arguments ...]
393#
394# Display a message in a dialog box with ``Error'' i18n title (overridden by
395# setting msg_error) using printf(1) syntax.
396#
397f_show_err()
398{
399	local msg
400	msg=$( printf "$@" )
401
402	: ${msg:=${msg_an_unknown_error_occurred:-An unknown error occurred}}
403
404	if [ "$_DIALOG_SUBR" ]; then
405		f_dialog_title "${msg_error:-Error}"
406		f_dialog_msgbox "$msg"
407		f_dialog_title_restore
408	else
409		dialog --title "${msg_error:-Error}" --msgbox "$msg" 0 0
410	fi
411	return $SUCCESS
412}
413
414# f_yesno $format [$arguments ...]
415#
416# Display a message in a dialog yes/no box using printf(1) syntax.
417#
418f_yesno()
419{
420	local msg
421	msg=$( printf "$@" )
422
423	#
424	# Use f_dialog_yesno from dialog.subr if possible, otherwise fall
425	# back to dialog(1) (without options, making it obvious when using
426	# un-aided system dialog).
427	#
428	if f_have f_dialog_yesno; then
429		f_dialog_yesno "$msg"
430	else
431		dialog --yesno "$msg" 0 0
432	fi
433}
434
435# f_noyes $format [$arguments ...]
436#
437# Display a message in a dialog yes/no box using printf(1) syntax.
438# NOTE: THis is just like the f_yesno function except "No" is default.
439#
440f_noyes()
441{
442	local msg
443	msg=$( printf "$@" )
444
445	#
446	# Use f_dialog_noyes from dialog.subr if possible, otherwise fall
447	# back to dialog(1) (without options, making it obvious when using
448	# un-aided system dialog).
449	#
450	if f_have f_dialog_noyes; then
451		f_dialog_noyes "$msg"
452	else
453		dialog --defaultno --yesno "$msg" 0 0
454	fi
455}
456
457# f_show_help $file
458#
459# Display a language help-file. Automatically takes $LANG and $LC_ALL into
460# consideration when displaying $file (suffix ".$LC_ALL" or ".$LANG" will
461# automatically be added prior to loading the language help-file).
462#
463# If a language has been requested by setting either $LANG or $LC_ALL in the
464# environment and the language-specific help-file does not exist we will fall
465# back to $file without-suffix.
466#
467# If the language help-file does not exist, an error is displayed instead.
468#
469f_show_help()
470{
471	local file="$1"
472	local lang="${LANG:-$LC_ALL}"
473
474	[ -f "$file.$lang" ] && file="$file.$lang"
475
476	#
477	# Use f_dialog_textbox from dialog.subr if possible, otherwise fall
478	# back to dialog(1) (without options, making it obvious when using
479	# un-aided system dialog).
480	#
481	if f_have f_dialog_textbox; then
482		f_dialog_textbox "$file"
483	else
484		dialog --msgbox "$( cat "$file" 2>&1 )" 0 0
485	fi
486}
487
488# f_include $file
489#
490# Include a shell subroutine file.
491#
492# If the subroutine file exists but returns error status during loading, exit
493# is called and execution is prematurely terminated with the same error status.
494#
495f_include()
496{
497	local file="$1"
498	f_dprintf "f_include: file=[%s]" "$file"
499	. "$file" || exit $?
500}
501
502# f_include_lang $file
503#
504# Include a language file. Automatically takes $LANG and $LC_ALL into
505# consideration when including $file (suffix ".$LC_ALL" or ".$LANG" will
506# automatically by added prior to loading the language file).
507#
508# No error is produced if (a) a language has been requested (by setting either
509# $LANG or $LC_ALL in the environment) and (b) the language file does not
510# exist -- in which case we will fall back to loading $file without-suffix.
511#
512# If the language file exists but returns error status during loading, exit
513# is called and execution is prematurely terminated with the same error status.
514#
515f_include_lang()
516{
517	local file="$1"
518	local lang="${LANG:-$LC_ALL}"
519
520	f_dprintf "f_include_lang: file=[%s] lang=[%s]" "$file" "$lang"
521	if [ -f "$file.$lang" ]; then
522		. "$file.$lang" || exit $?
523	else
524		. "$file" || exit $?
525	fi
526}
527
528# f_usage $file [$key1 $value1 ...]
529#
530# Display USAGE file with optional pre-processor macro definitions. The first
531# argument is the template file containing the usage text to be displayed. If
532# $LANG or $LC_ALL (in order of preference, respectively) is set, ".encoding"
533# will automatically be appended as a suffix to the provided $file pathname.
534#
535# When processing $file, output begins at the first line containing that is
536# (a) not a comment, (b) not empty, and (c) is not pure-whitespace. All lines
537# appearing after this first-line are output, including (a) comments (b) empty
538# lines, and (c) lines that are purely whitespace-only.
539#
540# If additional arguments appear after $file, substitutions are made while
541# printing the contents of the USAGE file. The pre-processor macro syntax is in
542# the style of autoconf(1), for example:
543#
544# 	f_usage $file "FOO" "BAR"
545#
546# Will cause instances of "@FOO@" appearing in $file to be replaced with the
547# text "BAR" before being printed to the screen.
548#
549# This function is a two-parter. Below is the awk(1) portion of the function,
550# afterward is the sh(1) function which utilizes the below awk script.
551#
552f_usage_awk='
553BEGIN { found = 0 }
554{
555	if ( !found && $0 ~ /^[[:space:]]*($|#)/ ) next
556	found = 1
557	print
558}
559'
560f_usage()
561{
562	local file="$1"
563	local lang="${LANG:-$LC_ALL}"
564
565	f_dprintf "f_usage: file=[%s] lang=[%s]" "$file" "$lang"
566
567	shift 1 # file
568
569	local usage
570	if [ -f "$file.$lang" ]; then
571		usage=$( awk "$f_usage_awk" "$file.$lang" ) || exit $FAILURE
572	else
573		usage=$( awk "$f_usage_awk" "$file" ) || exit $FAILURE
574	fi
575
576	while [ $# -gt 0 ]; do
577		local key="$1"
578		export value="$2"
579		usage=$( echo "$usage" | awk \
580			"{ gsub(/@$key@/, ENVIRON[\"value\"]); print }" )
581		shift 2
582	done
583
584	f_err "%s\n" "$usage"
585
586	exit $FAILURE
587}
588
589# f_index_file $keyword [$var_to_set]
590#
591# Process all INDEX files known to bsdconfig and return the path to first file
592# containing a menu_selection line with a keyword portion matching $keyword.
593#
594# If $LANG or $LC_ALL (in order of preference, respectively) is set,
595# "INDEX.encoding" files will be searched first.
596#
597# If no file is found, error status is returned along with the NULL string.
598#
599# If $var_to_set is NULL or missing, output is printed to stdout (which is less
600# recommended due to performance degradation; in a loop for example).
601#
602# This function is a two-parter. Below is the awk(1) portion of the function,
603# afterward is the sh(1) function which utilizes the below awk script.
604#
605f_index_file_awk='
606# Variables that should be defined on the invocation line:
607# 	-v keyword="keyword"
608BEGIN { found = 0 }
609( $0 ~ "^menu_selection=\"" keyword "\\|" ) {
610	print FILENAME
611	found++
612	exit
613}
614END { exit ! found }
615'
616f_index_file()
617{
618	local __keyword="$1" __var_to_set="$2"
619	local __lang="${LANG:-$LC_ALL}"
620	local __indexes="$BSDCFG_LIBE${BSDCFG_LIBE:+/}*/INDEX"
621
622	f_dprintf "f_index_file: keyword=[%s] lang=[%s]" "$__keyword" "$__lang"
623
624	if [ "$__lang" ]; then
625		if [ "$__var_to_set" ]; then
626			eval "$__var_to_set"='"$( awk -v keyword="$__keyword" \
627				"$f_index_file_awk" $__indexes.$__lang
628			)"' && return $SUCCESS
629		else
630			awk -v keyword="$__keyword" "$f_index_file_awk" \
631				$__indexes.$__lang && return $SUCCESS
632		fi
633		# No match, fall-thru to non-i18n sources
634	fi
635	if [ "$__var_to_set" ]; then
636		eval "$__var_to_set"='"$( awk -v keyword="$__keyword" \
637			"$f_index_file_awk" $__indexes )"' && return $SUCCESS
638	else
639		awk -v keyword="$__keyword" "$f_index_file_awk" $__indexes &&
640			return $SUCCESS
641	fi
642
643	# No match? Fall-thru to `local' libexec sources (add-on modules)
644
645	[ "$BSDCFG_LOCAL_LIBE" ] || return $FAILURE
646	__indexes="$BSDCFG_LOCAL_LIBE/*/INDEX"
647	if [ "$__lang" ]; then
648		if [ "$__var_to_set" ]; then
649			eval "$__var_to_set"='"$( awk -v keyword="$__keyword" \
650				"$f_index_file_awk" $__indexes.$__lang
651			)"' && return $SUCCESS
652		else
653			awk -v keyword="$__keyword" "$f_index_file_awk" \
654				$__indexes.$__lang && return $SUCCESS
655		fi
656		# No match, fall-thru to non-i18n sources
657	fi
658	if [ "$__var_to_set" ]; then
659		eval "$__var_to_set"='$( awk -v keyword="$__keyword" \
660			"$f_index_file_awk" $__indexes )"'
661	else
662		awk -v keyword="$__keyword" "$f_index_file_awk" $__indexes
663	fi
664}
665
666# f_index_menusel_keyword $indexfile $pgm [$var_to_set]
667#
668# Process $indexfile and return only the keyword portion of the menu_selection
669# line with a command portion matching $pgm.
670#
671# This function is for internationalization (i18n) mapping of the on-disk
672# scriptname ($pgm) into the localized language (given language-specific
673# $indexfile). If $LANG or $LC_ALL (in orderder of preference, respectively) is
674# set, ".encoding" will automatically be appended as a suffix to the provided
675# $indexfile pathname.
676#
677# If, within $indexfile, multiple $menu_selection values map to $pgm, only the
678# first one will be returned. If no mapping can be made, the NULL string is
679# returned.
680#
681# If $indexfile does not exist, error status is returned with NULL.
682#
683# If $var_to_set is NULL or missing, output is printed to stdout (which is less
684# recommended due to performance degradation; in a loop for example).
685#
686# This function is a two-parter. Below is the awk(1) portion of the function,
687# afterward is the sh(1) function which utilizes the below awk script.
688#
689f_index_menusel_keyword_awk='
690# Variables that should be defined on the invocation line:
691# 	-v pgm="program_name"
692#
693BEGIN {
694	prefix = "menu_selection=\""
695	plen = length(prefix)
696	found = 0
697}
698{
699	if (!match($0, "^" prefix ".*\\|.*\"")) next
700
701	keyword = command = substr($0, plen + 1, RLENGTH - plen - 1)
702	sub(/^.*\|/, "", command)
703	sub(/\|.*$/, "", keyword)
704
705	if ( command == pgm )
706	{
707		print keyword
708		found++
709		exit
710	}
711}
712END { exit ! found }
713'
714f_index_menusel_keyword()
715{
716	local __indexfile="$1" __pgm="$2" __var_to_set="$3"
717	local __lang="${LANG:-$LC_ALL}" __file="$__indexfile"
718
719	[ -f "$__indexfile.$__lang" ] && __file="$__indexfile.$__lang"
720	f_dprintf "f_index_menusel_keyword: index=[%s] pgm=[%s] lang=[%s]" \
721	          "$__file" "$__pgm" "$__lang"
722
723	if [ "$__var_to_set" ]; then
724		setvar "$__var_to_set" "$( awk \
725		    -v pgm="$__pgm" "$f_index_menusel_keyword_awk" "$__file"
726		)"
727	else
728		awk -v pgm="$__pgm" "$f_index_menusel_keyword_awk" "$__file"
729	fi
730}
731
732# f_index_menusel_command $indexfile $keyword [$var_to_set]
733#
734# Process $indexfile and return only the command portion of the menu_selection
735# line with a keyword portion matching $keyword.
736#
737# This function is for mapping [possibly international] keywords into the
738# command to be executed. If $LANG or $LC_ALL (order of preference) is set,
739# ".encoding" will automatically be appended as a suffix to the provided
740# $indexfile pathname.
741#
742# If, within $indexfile, multiple $menu_selection values map to $keyword, only
743# the first one will be returned. If no mapping can be made, the NULL string is
744# returned.
745#
746# If $indexfile doesn't exist, error status is returned with NULL.
747#
748# If $var_to_set is NULL or missing, output is printed to stdout (which is less
749# recommended due to performance degradation; in a loop for example).
750#
751# This function is a two-parter. Below is the awk(1) portion of the function,
752# afterward is the sh(1) function which utilizes the below awk script.
753#
754f_index_menusel_command_awk='
755# Variables that should be defined on the invocation line:
756# 	-v key="keyword"
757#
758BEGIN {
759	prefix = "menu_selection=\""
760	plen = length(prefix)
761	found = 0
762}
763{
764	if (!match($0, "^" prefix ".*\\|.*\"")) next
765
766	keyword = command = substr($0, plen + 1, RLENGTH - plen - 1)
767	sub(/^.*\|/, "", command)
768	sub(/\|.*$/, "", keyword)
769
770	if ( keyword == key )
771	{
772		print command
773		found++
774		exit
775	}
776}
777END { exit ! found }
778'
779f_index_menusel_command()
780{
781	local __indexfile="$1" __keyword="$2" __var_to_set="$3" __command
782	local __lang="${LANG:-$LC_ALL}" __file="$__indexfile"
783
784	[ -f "$__indexfile.$__lang" ] && __file="$__indexfile.$__lang"
785	f_dprintf "f_index_menusel_command: index=[%s] key=[%s] lang=[%s]" \
786	          "$__file" "$__keyword" "$__lang"
787
788	[ -f "$__file" ] || return $FAILURE
789	__command=$( awk -v key="$__keyword" \
790		"$f_index_menusel_command_awk" "$__file" ) || return $FAILURE
791
792	#
793	# If the command pathname is not fully qualified fix-up/force to be
794	# relative to the $indexfile directory.
795	#
796	case "$__command" in
797	/*) : already fully qualified ;;
798	*)
799		local __indexdir="${__indexfile%/*}"
800		[ "$__indexdir" != "$__indexfile" ] || __indexdir="."
801		__command="$__indexdir/$__command"
802	esac
803
804	if [ "$__var_to_set" ]; then
805		setvar "$__var_to_set" "$__command"
806	else
807		echo "$__command"
808	fi
809}
810
811# f_running_as_init
812#
813# Returns true if running as init(1).
814#
815f_running_as_init()
816{
817	#
818	# When a custom init(8) performs an exec(3) to invoke a shell script,
819	# PID 1 becomes sh(1) and $PPID is set to 1 in the executed script.
820	#
821	[ ${PPID:-0} -eq 1 ] # Return status
822}
823
824# f_mounted $local_directory
825# f_mounted -b $device
826#
827# Return success if a filesystem is mounted on a particular directory. If `-b'
828# is present, instead check that the block device (or a partition thereof) is
829# mounted.
830#
831f_mounted()
832{
833	local OPTIND OPTARG flag use_device=
834	while getopts b flag; do
835		case "$flag" in
836		b) use_device=1 ;;
837		esac
838	done
839	shift $(( $OPTIND - 1 ))
840	if [ "$use_device" ]; then
841		local device="$1"
842		mount | grep -Eq \
843			"^$device([[:space:]]|p[0-9]|s[0-9]|\.nop|\.eli)"
844	else
845		[ -d "$dir" ] || return $FAILURE
846		mount | grep -Eq " on $dir \([^)]+\)$"
847	fi
848	# Return status is that of last grep(1)
849}
850
851# f_eval_catch [-de] [-k $var_to_set] $funcname $utility \
852#              $format [$arguments ...]
853#
854# Silently evaluate a command in a sub-shell and test for error. If debugging
855# is enabled a copy of the command and its output is sent to debug (either
856# stdout or file depending on environment). If an error occurs, output of the
857# command is displayed in a dialog(1) msgbox using the [above] f_show_err()
858# function (unless optional `-d' flag is given, then no dialog).
859#
860# The $funcname argument is sent to debugging while the $utility argument is
861# used in the title of the dialog box. The command that is executed as well as
862# sent to debugging with $funcname is the product of the printf(1) syntax
863# produced by $format with optional $arguments.
864#
865# The following options are supported:
866#
867# 	-d	Do not use dialog(1).
868# 	-e	Produce error text from failed command on stderr.
869# 	-k var	Save output from the command in var.
870#
871# Example 1:
872#
873# 	debug=1
874# 	f_eval_catch myfunc echo 'echo "%s"' "Hello, World!"
875#
876# 	Produces the following debug output:
877#
878# 		DEBUG: myfunc: echo "Hello, World!"
879# 		DEBUG: myfunc: retval=0 <output below>
880# 		Hello, World!
881#
882# Example 2:
883#
884# 	debug=1
885# 	f_eval_catch -k contents myfunc cat 'cat "%s"' /some/file
886# 	# dialog(1) Error ``cat: /some/file: No such file or directory''
887# 	# contents=[cat: /some/file: No such file or directory]
888#
889# 	Produces the following debug output:
890#
891# 		DEBUG: myfunc: cat "/some/file"
892# 		DEBUG: myfunc: retval=1 <output below>
893# 		cat: /some/file: No such file or directory
894#
895# Example 3:
896#
897# 	debug=1
898# 	echo 123 | f_eval_catch myfunc rev rev
899#
900# 	Produces the following debug output:
901#
902# 		DEBUG: myfunc: rev
903# 		DEBUG: myfunc: retval=0 <output below>
904# 		321
905#
906# Example 4:
907#
908# 	debug=1
909# 	f_eval_catch myfunc true true
910#
911# 	Produces the following debug output:
912#
913# 		DEBUG: myfunc: true
914# 		DEBUG: myfunc: retval=0 <no output>
915#
916# Example 5:
917#
918# 	f_eval_catch -de myfunc ls 'ls "%s"' /some/dir
919# 	# Output on stderr ``ls: /some/dir: No such file or directory''
920#
921# Example 6:
922#
923# 	f_eval_catch -dek contents myfunc ls 'ls "%s"' /etc
924# 	# Output from `ls' sent to stderr and also saved in $contents
925#
926f_eval_catch()
927{
928	local __no_dialog= __show_err= __var_to_set=
929
930	#
931	# Process local function arguments
932	#
933	local OPTIND OPTARG __flag
934	while getopts "dek:" __flag > /dev/null; do
935		case "$__flag" in
936		d) __no_dialog=1 ;;
937		e) __show_err=1 ;;
938		k) __var_to_set="$OPTARG" ;;
939		esac
940	done
941	shift $(( $OPTIND - 1 ))
942
943	local __funcname="$1" __utility="$2"; shift 2
944	local __cmd __output __retval
945
946	__cmd=$( printf -- "$@" )
947	f_dprintf "%s: %s" "$__funcname" "$__cmd" # Log command *before* eval
948	__output=$( exec 2>&1; eval "$__cmd" )
949	__retval=$?
950	if [ "$__output" ]; then
951		[ "$__show_err" ] && echo "$__output" >&2
952		f_dprintf "%s: retval=%i <output below>\n%s" "$__funcname" \
953		          $__retval "$__output"
954	else
955		f_dprintf "%s: retval=%i <no output>" "$__funcname" $__retval
956	fi
957
958	! [ "$__no_dialog" -o "$nonInteractive" -o $__retval -eq $SUCCESS ] &&
959		msg_error="${msg_error:-Error}${__utility:+: $__utility}" \
960			f_show_err "%s" "$__output"
961		# NB: f_show_err will handle NULL output appropriately
962
963	[ "$__var_to_set" ] && setvar "$__var_to_set" "$__output"
964
965	return $__retval
966}
967
968# f_count $var_to_set arguments ...
969#
970# Sets $var_to_set to the number of arguments minus one (the effective number
971# of arguments following $var_to_set).
972#
973# Example:
974# 	f_count count dog house # count=[2]
975#
976f_count()
977{
978	setvar "$1" $(( $# - 1 ))
979}
980
981# f_count_ifs $var_to_set string ...
982#
983# Sets $var_to_set to the number of words (split by the internal field
984# separator, IFS) following $var_to_set.
985#
986# Example 1:
987#
988# 	string="word1   word2   word3"
989# 	f_count_ifs count "$string" # count=[3]
990# 	f_count_ifs count $string # count=[3]
991#
992# Example 2:
993#
994# 	IFS=. f_count_ifs count www.freebsd.org # count=[3]
995#
996# NB: Make sure to use double-quotes if you are using a custom value for IFS
997# and you don't want the current value to effect the result. See example 3.
998#
999# Example 3:
1000#
1001# 	string="a-b c-d"
1002# 	IFS=- f_count_ifs count "$string" # count=[3]
1003# 	IFS=- f_count_ifs count $string # count=[4]
1004#
1005f_count_ifs()
1006{
1007	local __var_to_set="$1"
1008	shift 1
1009	set -- $*
1010	setvar "$__var_to_set" $#
1011}
1012
1013############################################################ MAIN
1014
1015#
1016# Trap signals so we can recover gracefully
1017#
1018trap 'f_interrupt' INT
1019trap 'f_die' TERM PIPE XCPU XFSZ FPE TRAP ABRT SEGV
1020trap '' ALRM PROF USR1 USR2 HUP VTALRM
1021
1022#
1023# Clone terminal stdout/stderr so we can redirect to it from within sub-shells
1024#
1025eval exec $TERMINAL_STDOUT_PASSTHRU\>\&1
1026eval exec $TERMINAL_STDERR_PASSTHRU\>\&2
1027
1028#
1029# Self-initialize unless requested otherwise
1030#
1031f_dprintf "%s: DEBUG_SELF_INITIALIZE=[%s]" \
1032          dialog.subr "$DEBUG_SELF_INITIALIZE"
1033case "$DEBUG_SELF_INITIALIZE" in
1034""|0|[Nn][Oo]|[Oo][Ff][Ff]|[Ff][Aa][Ll][Ss][Ee]) : do nothing ;;
1035*) f_debug_init
1036esac
1037
1038#
1039# Log our operating environment for debugging purposes
1040#
1041f_dprintf "UNAME_S=[%s] UNAME_P=[%s] UNAME_R=[%s]" \
1042          "$UNAME_S" "$UNAME_P" "$UNAME_R"
1043
1044f_dprintf "%s: Successfully loaded." common.subr
1045
1046fi # ! $_COMMON_SUBR
1047