path: root/usr.sbin/bsdconfig/share/common.subr

if [ ! "$_COMMON_SUBR" ]; then _COMMON_SUBR=1
#
# Copyright (c) 2012 Ron McDowell
# Copyright (c) 2012 Devin Teske
# All rights reserved.
#
# Redistribution and use in source and binary forms, with or without
# modification, are permitted provided that the following conditions
# are met:
# 1. Redistributions of source code must retain the above copyright
#    notice, this list of conditions and the following disclaimer.
# 2. Redistributions in binary form must reproduce the above copyright
#    notice, this list of conditions and the following disclaimer in the
#    documentation and/or other materials provided with the distribution.
#
# THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
# ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
# IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
# ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
# FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
# DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
# OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
# HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
# LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
# OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
# SUCH DAMAGE.
#
# $FreeBSD$
#
############################################################ CONFIGURATION

#
# Default file descriptors to link to stdout/stderr for passthru allowing
# redirection within a sub-shell to bypass directly to the terminal.
#
: ${TERMINAL_STDOUT_PASSTHRU:=3}}
: ${TERMINAL_STDERR_PASSTHRU:=4}}

############################################################ GLOBALS

#
# Program name
#
pgm="${0##*/}"

#
# Program arguments
#
ARGC="$#"
ARGV="$@"

#
# Global exit status variables
#
SUCCESS=0
FAILURE=1

############################################################ FUNCTIONS

#
# This is an empty function by default, to use it, copy
# /usr/share/examples/bsdconfig/bsdconfigrc to $HOME/.bsdconfigrc
#
f_dprintf()
{
	: this page intentionally left blank
}
[ "$DEBUGGING" ] && f_dprintf()
{
	local fmt="$1"
	shift
	printf "$fmt${fmt:+\n}" "$@" \
		>&${TERMINAL_STDOUT_PASSTHRU:-1}
} &&
	export DEBUGGING

# f_err $fmt [ $opts ... ]
#
# Print a message to stderr (fd=2).
#
f_err()
{
	printf "$@" >&${TERMINAL_STDERR_PASSTHRU:-2}
}

# f_quietly $command [ $arguments ... ]
#
# Run a command quietly (quell any output to stdout or stderr)
#
f_quietly()
{
	"$@" > /dev/null 2>&1
}

# f_have $anything ...
#
# A wrapper to the `type' built-in. Returns true if argument is a valid shell
# built-in, keyword, or externally-tracked binary, otherwise false.
#
f_have()
{
	f_quietly type "$@"
}

# f_die [ $status [ $fmt [ $opts ... ]]]
#
# Abruptly terminate due to an error optionally displaying a message in a
# dialog box using printf(1) syntax.
#
f_die()
{
	local status=$FAILURE

	# If there is at least one argument, take it as the status
	if [ $# -gt 0 ]; then
		status=$1
		shift 1 # status
	fi

	# If there are still arguments left, pass them to f_show_msg
	[ $# -gt 0 ] && f_show_msg "$@"

	# Optionally call f_clean_up() function if it exists
	f_have f_clean_up && f_clean_up

	exit $status
}

# f_interrupt
#
# Interrupt handler.
#
f_interrupt()
{
	exec 2>&1 # fix sh(1) bug where stderr gets lost within async-trap
	f_die
}

# f_show_msg $fmt [ $opts ... ]
#
# Display a message in a dialog box using printf(1) syntax.
#
f_show_msg()
{
	local msg
	msg=$( printf "$@" )

	#
	# Use f_dialog_msgbox from dialog.subr if possible, otherwise fall
	# back to dialog(1) (without options, making it obvious when using
	# un-aided system dialog).
	#
	if f_have f_dialog_msgbox; then
		f_dialog_msgbox "$msg"
	else
		dialog --msgbox "$msg" 0 0
	fi
}

# f_show_help $file
#
# Display a language help-file. Automatically takes $LANG and $LC_ALL into
# consideration when displaying $file (suffix ".$LC_ALL" or ".$LANG" will
# automatically be added prior to loading the language help-file).
#
# If a language has been requested by setting either $LANG or $LC_ALL in the
# environment and the language-specific help-file does not exist we will fall
# back to $file without-suffix.
#
# If the language help-file does not exist, an error is displayed instead.
#
f_show_help()
{
	local file="$1"
	local lang="${LANG:-$LC_ALL}"

	[ -f "$file.$lang" ] && file="$file.$lang"

	#
	# Use f_dialog_textbox from dialog.subr if possible, otherwise fall
	# back to dialog(1) (without options, making it obvious when using
	# un-aided system dialog).
	#
	if f_have f_dialog_textbox; then
		f_dialog_textbox "$file"
	else
		dialog --msgbox "$( cat "$file" 2>&1 )" 0 0
	fi
}

# f_include $file
#
# Include a shell subroutine file.
#
# If the subroutine file exists but returns error status during loading, exit
# is called and execution is prematurely terminated with the same error status.
#
f_include()
{
	local file="$1"
	f_dprintf "f_include: file=[%s]" "$file"
	. "$file" || exit $?
}

# f_include_lang $file
#
# Include a language file. Automatically takes $LANG and $LC_ALL into
# consideration when including $file (suffix ".$LC_ALL" or ".$LANG" will
# automatically by added prior to loading the language file).
#
# No error is produced if (a) a language has been requested (by setting either
# $LANG or $LC_ALL in the environment) and (b) the language file does not
# exist -- in which case we will fall back to loading $file without-suffix.
#
# If the language file exists but returns error status during loading, exit
# is called and execution is prematurely terminated with the same error status.
#
f_include_lang()
{
	local file="$1"
	local lang="${LANG:-$LC_ALL}"

	f_dprintf "f_include_lang: file=[%s] lang=[%s]" "$file" "$lang"
	if [ -f "$file.$lang" ]; then
		. "$file.$lang" || exit $?
	else
		. "$file" || exit $?
	fi
}

# f_usage $file [ $key1 $value1 ... ]
#
# Display USAGE file with optional pre-processor macro definitions. The first
# argument is the template file containing the usage text to be displayed. If
# $LANG or $LC_ALL (in order of preference, respectively) is set, ".encoding"
# will automatically be appended as a suffix to the provided $file pathname.
#
# When processing $file, output begins at the first line containing that is
# (a) not a comment, (b) not empty, and (c) is not pure-whitespace. All lines
# appearing after this first-line are output, including (a) comments (b) empty
# lines, and (c) lines that are purely whitespace-only.
#
# If additional arguments appear after $file, substitutions are made while
# printing the contents of the USAGE file. The pre-processor macro syntax is in
# the style of autoconf(1), for example:
#
# 	f_usage $file "FOO" "BAR"
#
# Will cause instances of "@FOO@" appearing in $file to be replaced with the
# text "BAR" before bering printed to the screen.
#
# This function is a two-parter. Below is the awk(1) portion of the function,
# afterward is the sh(1) function which utilizes the below awk script.
#
f_usage_awk='
BEGIN { found = 0 }
{
	if ( !found && $0 ~ /^[[:space:]]*($|#)/ ) next
	found = 1
	print
}
'
f_usage()
{
	local file="$1"
	local lang="${LANG:-$LC_ALL}"

	f_dprintf "f_usage: file=[%s] lang=[%s]" "$file" "$lang"

	shift 1 # file

	local usage
	if [ -f "$file.$lang" ]; then
		usage=$( awk "$f_usage_awk" "$file.$lang" ) || exit $FAILURE
	else
		usage=$( awk "$f_usage_awk" "$file" ) || exit $FAILURE
	fi

	while [ $# -gt 0 ]; do
		local key="$1"
		export value="$2"
		usage=$( echo "$usage" | awk \
			"{ gsub(/@$key@/, ENVIRON[\"value\"]); print }" )
		shift 2
	done

	f_err "%s\n" "$usage"

	exit $FAILURE
}

# f_index_file $keyword
#
# Process all INDEX files known to bsdconfig and return the path to first file
# containing a menu_selection line with a keyword portion matching $keyword.
#
# If $LANG or $LC_ALL (in order of preference, respectively) is set,
# "INDEX.encoding" files will be searched first.
#
# If no file is found, error status is returned along with the NULL string.
#
# This function is a two-parter. Below is the awk(1) portion of the function,
# afterward is the sh(1) function which utilizes the below awk script.
#
f_index_file_awk='
# Variables that should be defined on the invocation line:
# 	-v keyword="keyword"
BEGIN { found = 0 }
( $0 ~ "^menu_selection=\"" keyword "\\|" ) {
	print FILENAME
	found++
	exit
}
END { exit ! found }
'
f_index_file()
{
	local keyword="$1"
	local lang="${LANG:-$LC_ALL}"

	f_dprintf "f_index_file: keyword=[%s] lang=[%s]" "$keyword" "$lang"

	if [ "$lang" ]; then
		awk -v keyword="$keyword" "$f_index_file_awk" \
			$BSDCFG_LIBE${BSDCFG_LIBE:+/}*/INDEX.$lang &&
			return
		# No match, fall-thru to non-i18n sources
	fi
	awk -v keyword="$keyword" "$f_index_file_awk" \
		$BSDCFG_LIBE${BSDCFG_LIBE:+/}*/INDEX
}

# f_index_menusel_keyword $indexfile $pgm
#
# Process $indexfile and return only the keyword portion of the menu_selection
# line with a command portion matching $pgm.
#
# This function is for internationalization (i18n) mapping of the on-disk
# scriptname ($pgm) into the localized language (given language-specific
# $indexfile). If $LANG or $LC_ALL (in orderder of preference, respectively) is
# set, ".encoding" will automatically be appended as a suffix to the provided
# $indexfile pathname.
#
# If, within $indexfile, multiple $menu_selection values map to $pgm, only the
# first one will be returned. If no mapping can be made, the NULL string is
# returned.
#
# If $indexfile does not exist, error status is returned with NULL.
#
# This function is a two-parter. Below is the awk(1) portion of the function,
# afterward is the sh(1) function which utilizes the below awk script.
#
f_index_menusel_keyword_awk='
# Variables that should be defined on the invocation line:
# 	-v pgm="program_name"
#
BEGIN {
	prefix = "menu_selection=\""
	plen = length(prefix)
	found = 0
}
{
	if (!match($0, "^" prefix ".*\\|.*\"")) next

	keyword = command = substr($0, plen + 1, RLENGTH - plen - 1)
	sub(/^.*\|/, "", command)
	sub(/\|.*$/, "", keyword)

	if ( command == pgm )
	{
		print keyword
		found++
		exit
	}
}
END { exit ! found }
'
f_index_menusel_keyword()
{
	local indexfile="$1" pgm="$2"
	local lang="${LANG:-$LC_ALL}"

	f_dprintf "f_index_menusel_keyword: index=[%s] pgm=[%s] lang=[%s]" \
	          "$indexfile" "$pgm" "$lang"

	if [ -f "$indexfile.$lang" ]; then
		awk -v pgm="$pgm" \
			"$f_index_menusel_keyword_awk" \
			"$indexfile.$lang"
	elif [ -f "$indexfile" ]; then
		awk -v pgm="$pgm" \
			"$f_index_menusel_keyword_awk" \
			"$indexfile"
	fi
}

# f_index_menusel_command $indexfile $keyword
#
# Process $indexfile and return only the command portion of the menu_selection
# line with a keyword portion matching $keyword.
#
# This function is for mapping [possibly international] keywords into the
# command to be executed. If $LANG or $LC_ALL (order of preference) is set,
# ".encoding" will automatically be appended as a suffix to the provided
# $indexfile pathname.
#
# If, within $indexfile, multiple $menu_selection values map to $keyword, only
# the first one will be returned. If no mapping can be made, the NULL string is
# returned.
#
# If $indexfile doesn't exist, error status is returned with NULL.
#
# This function is a two-parter. Below is the awk(1) portion of the function,
# afterward is the sh(1) function which utilizes the below awk script.
#
f_index_menusel_command_awk='
# Variables that should be defined on the invocation line:
# 	-v key="keyword"
#
BEGIN {
	prefix = "menu_selection=\""
	plen = length(prefix)
	found = 0
}
{
	if (!match($0, "^" prefix ".*\\|.*\"")) next

	keyword = command = substr($0, plen + 1, RLENGTH - plen - 1)
	sub(/^.*\|/, "", command)
	sub(/\|.*$/, "", keyword)

	if ( keyword == key )
	{
		print command
		found++
		exit
	}
}
END { exit ! found }
'
f_index_menusel_command()
{
	local indexfile="$1" keyword="$2" command
	local lang="${LANG:-$LC_ALL}"

	f_dprintf "f_index_menusel_command: index=[%s] key=[%s] lang=[%s]" \
	          "$indexfile" "$keyword" "$lang"

	if [ -f "$indexfile.$lang" ]; then
		command=$( awk -v key="$keyword" \
				"$f_index_menusel_command_awk" \
				"$indexfile.$lang" ) || return $FAILURE
	elif [ -f "$indexfile" ]; then
		command=$( awk -v key="$keyword" \
				"$f_index_menusel_command_awk" \
				"$indexfile" ) || return $FAILURE
	else
		return $FAILURE
	fi

	#
	# If the command pathname is not fully qualified fix-up/force to be
	# relative to the $indexfile directory.
	#
	case "$command" in
	/*) : already fully qualified ;;
	*)
		local indexdir="${indexfile%/*}"
		[ "$indexdir" != "$indexfile" ] || indexdir="."
		command="$indexdir/$command"
	esac

	echo "$command"
}

############################################################ MAIN

#
# Trap signals so we can recover gracefully
#
trap 'f_interrupt' SIGINT
trap 'f_die' SIGTERM SIGPIPE SIGXCPU SIGXFSZ \
             SIGFPE SIGTRAP SIGABRT SIGSEGV
trap '' SIGALRM SIGPROF SIGUSR1 SIGUSR2 SIGHUP SIGVTALRM

#
# Clone terminal stdout/stderr so we can redirect to it from within sub-shells
#
eval exec $TERMINAL_STDOUT_PASSTHRU\>\&1
eval exec $TERMINAL_STDERR_PASSTHRU\>\&2

fi # ! $_COMMON_SUBR