lfs-book-zh_CN/bootscripts/lfs/init.d/functions

#!/bin/sh
########################################################################
# Begin $rc_base/init.d/functions
#
# Description : Run Level Control Functions
#
# Authors     : Gerard Beekmans - gerard@linuxfromscratch.org
#
# Version     : 00.00
#
# Notes       : With code based on Matthias Benkmann's simpleinit-msb
#		http://winterdrache.de/linux/newboot/index.html
#
########################################################################

## Environmental setup
# Setup default values for environment
umask 022
export PATH="/bin:/usr/bin:/sbin:/usr/sbin"

# Signal sent to running processes to refresh their configuration
RELOADSIG="HUP"

# Number of seconds between STOPSIG and FALLBACK when stopping processes
KILLDELAY="3"

## Screen Dimensions
# Find current screen size
if [ -z "${COLUMNS}" ]; then
	COLUMNS=$(stty size)
	COLUMNS=${COLUMNS##* }
fi

# When using remote connections, such as a serial port, stty size returns 0
if [ "${COLUMNS}" = "0" ]; then 
	COLUMNS=80
fi

## Measurements for positioning result messages
COL=$((${COLUMNS} - 8))
WCOL=$((${COL} - 2))

## Provide an echo that supports -e and -n
# If formatting is needed, $ECHO should be used
case "`echo -e -n test`" in
	-[en]*)
		ECHO=/bin/echo
		;;
	*)
		ECHO=echo
		;;
esac

## Set Cursor Position Commands, used via $ECHO
SET_COL="\\033[${COL}G"      # at the $COL char
SET_WCOL="\\033[${WCOL}G"    # at the $WCOL char
CURS_UP="\\033[1A\\033[0G"   # Up one line, at the 0'th char

## Set color commands, used via $ECHO
# Please consult `man console_codes for more information
# under the "ECMA-48 Set Graphics Rendition" section
#
# Warning: when switching from a 8bit to a 9bit font,
# the linux console will reinterpret the bold (1;) to
# the top 256 glyphs of the 9bit font.  This does
# not affect framebuffer consoles
NORMAL="\\033[0;39m"         # Standard console grey
SUCCESS="\\033[1;32m"        # Success is green
WARNING="\\033[1;33m"        # Warnings are yellow
FAILURE="\\033[1;31m"        # Failures are red
INFO="\\033[1;36m"           # Information is light cyan
BRACKET="\\033[1;34m"        # Brackets are blue

STRING_LENGTH="0"   # the length of the current message

#*******************************************************************************
# Function - boot_mesg()
#
# Purpose:      Sending information from bootup scripts to the console
#
# Inputs:       $1 is the message
#               $2 is the colorcode for the console
#
# Outputs:      Standard Output
#
# Dependencies: - sed for parsing strings.
#	        - grep for counting string length.
#               
# Todo:         
#*******************************************************************************
boot_mesg()
{
	local ECHOPARM=""

	while true
	do
		case "${1}" in
			-n)
				ECHOPARM=" -n "
				shift 1
				;;
			-*)
				echo "Unknown Option: ${1}"
				return 1
				;;
			*)
				break
				;;
		esac
	done

	## Figure out the length of what is to be printed to be used
	## for warning messages. 
	STRING_LENGTH=$((${#1} + 1))

	# Print the message to the screen
	${ECHO} ${ECHOPARM} -e "${2}${1}"
	
}

boot_mesg_flush()
{
	# Reset STRING_LENGTH for next message
	STRING_LENGTH="0"
}

boot_log()
{
	# Left in for backwards compatibility
	:
}

echo_ok()
{
	${ECHO} -n -e "${CURS_UP}${SET_COL}${BRACKET}[${SUCCESS}  OK  ${BRACKET}]"
	${ECHO} -e "${NORMAL}"
        boot_mesg_flush
}

echo_failure()
{
	${ECHO} -n -e "${CURS_UP}${SET_COL}${BRACKET}[${FAILURE} FAIL ${BRACKET}]"
	${ECHO} -e "${NORMAL}"
        boot_mesg_flush
}

echo_warning()
{
	${ECHO} -n -e "${CURS_UP}${SET_COL}${BRACKET}[${WARNING} WARN ${BRACKET}]"
	${ECHO} -e "${NORMAL}"
        boot_mesg_flush
}

print_error_msg()
{
	echo_failure
	# $i is inherited by the rc script
	boot_mesg -n "FAILURE:\n\nYou should not be reading this error message.\n\n" ${FAILURE}
	boot_mesg -n " It means that an unforeseen error took"
	boot_mesg -n " place in ${i}, which exited with a return value of"
	boot_mesg " ${error_value}.\n"
	boot_mesg_flush
	boot_mesg -n "If you're able to track this"
	boot_mesg -n " error down to a bug in one of the files provided by"
	boot_mesg -n " the LFS book, please be so kind to inform us at"
	boot_mesg " lfs-dev@linuxfromscratch.org.\n"
	boot_mesg_flush
	boot_mesg -n "Press Enter to continue..." ${INFO}
	boot_mesg "" ${NORMAL}
	read ENTER
}

check_script_status()
{
	# $i is inherited by the rc script
	if [ ! -f ${i} ]; then
		boot_mesg "${i} is not a valid symlink." ${WARNING}
		echo_warning
		continue
	fi

	if [ ! -x ${i} ]; then
		boot_mesg "${i} is not executable, skipping." ${WARNING}
		echo_warning
		continue
	fi
}

evaluate_retval()
{
	error_value="${?}"

	if [ ${error_value} = 0 ]; then
		echo_ok
	else
		echo_failure
	fi

	# This prevents the 'An Unexpected Error Has Occurred' from trivial
	# errors.
	return 0
}

print_status()
{
	if [ "${#}" = "0" ]; then
		echo "Usage: ${0} {success|warning|failure}"
		return 1
	fi

	case "${1}" in

		success)
			echo_ok
			;;

		warning)
			# Leave this extra case in because old scripts
			# may call it this way.
			case "${2}" in
				running)
					${ECHO} -e -n "${CURS_UP}"
					${ECHO} -e -n "\\033[${STRING_LENGTH}G   "
					boot_mesg "Already running." ${WARNING}
					echo_warning
					;;
				not_running)
					${ECHO} -e -n "${CURS_UP}"
					${ECHO} -e -n "\\033[${STRING_LENGTH}G   "
					boot_mesg "Not running." ${WARNING}
					echo_warning
					;;
				not_available)
					${ECHO} -e -n "${CURS_UP}"
					${ECHO} -e -n "\\033[${STRING_LENGTH}G   "
					boot_mesg "Not available." ${WARNING}
					echo_warning
					;;
				*)
					# This is how it is supposed to
					# be called
					echo_warning
					;;
			esac
		;;

		failure)
			echo_failure
		;;

	esac

}

reloadproc()
{
	local pidfile=""
	local failure=0

	while true
	do
		case "${1}" in
			-p)
				pidfile="${2}"
				shift 2
				;;
			-*)
				log_failure_msg "Unknown Option: ${1}"
				return 2
				;;
			*)
				break
				;;
		esac
	done

	if [ "${#}" -lt "1" ]; then
		log_failure_msg "Usage: reloadproc [-p pidfile] pathname"
		return 2
	fi

	# This will ensure compatibility with previous LFS Bootscripts
	if [ -n "${PIDFILE}" ];	then
		pidfile="${PIDFILE}"
	fi

	# Is the process running?
	if [ -z "${pidfile}" ];	then
		pidofproc -s "${1}"
	else
		pidofproc -s -p "${pidfile}" "${1}"
	fi

	if [ -n "${pidlist}" ];	then
		for pid in ${pidlist}
		do
			kill -"${RELOADSIG}" "${pid}" || failure="1"
		done

		(exit ${failure})
		evaluate_retval

	else
		boot_mesg "Process ${1} not running." ${WARNING}
		echo_warning
	fi
}

statusproc()
{
	local pidfile=""
	local base=""
	local ret=""

	while true
	do
		case "${1}" in
			-p)
				pidfile="${2}"
				shift 2
				;;
			-*)
				log_failure_msg "Unknown Option: ${1}"
				return 2
				;;
			*)
				break
				;;
		esac
	done

	if [ "${#}" != "1" ]; then
		shift 1
		log_failure_msg "Usage: statusproc [-p pidfile] pathname"
		return 2
	fi

	# Get the process basename
	base="${1##*/}"

	# This will ensure compatibility with previous LFS Bootscripts
	if [ -n "${PIDFILE}" ];	then
		pidfile="${PIDFILE}"
	fi

	# Is the process running?
	if [ -z "${pidfile}" ];	then
		pidofproc -s "${1}"
	else
		pidofproc -s -p "${pidfile}" "${1}"
	fi

	# Store the return status
	ret=$?

	if [ -n "${pidlist}" ];	then
		${ECHO} -e "${INFO}${base} is running with Process"\
			"ID(s) ${pidlist}.${NORMAL}"
	else
		if [ -n "${base}" -a -e "/var/run/${base}.pid" ]; then
			${ECHO} -e "${WARNING}${1} is not running but"\
				"/var/run/${base}.pid exists.${NORMAL}"
		else
			if [ -n "${pidfile}" -a -e "${pidfile}" ]; then
				${ECHO} -e "${WARNING}${1} is not running"\
					"but ${pidfile} exists.${NORMAL}"
			else
				${ECHO} -e "${INFO}${1} is not running.${NORMAL}"
			fi
		fi
	fi

	# Return the status from pidofproc
	return $ret
}

# The below functions are documented in the LSB-generic 2.1.0

#*******************************************************************************
# Function - pidofproc [-s] [-p pidfile] pathname
#
# Purpose: This function returns one or more pid(s) for a particular daemon
#
# Inputs: -p pidfile, use the specified pidfile instead of pidof
#         pathname, path to the specified program
#
# Outputs: return 0 - Success, pid's in stdout
#          return 1 - Program is dead, pidfile exists
#          return 2 - Invalid or excessive number of arguments, 
#                     warning in stdout
#          return 3 - Program is not running
#
# Dependencies: pidof, echo, head
#
# Todo: Remove dependency on head
#       This depreciates getpids
#       Test changes to pidof
#
#*******************************************************************************
pidofproc()
{
	local pidfile=""
	local lpids=""
	local silent=""
	pidlist=""
	while true
	do
		case "${1}" in
			-p)
				pidfile="${2}"
				shift 2
				;;

			-s)
				# Added for legacy opperation of getpids
				# eliminates several '> /dev/null'
				silent="1"
				shift 1
				;;
			-*)
				log_failure_msg "Unknown Option: ${1}"
				return 2
				;;
			*)
				break
				;;
		esac
	done

	if [ "${#}" != "1" ]; then
		shift 1
		log_failure_msg "Usage: pidofproc [-s] [-p pidfile] pathname"
		return 2
	fi

	if [ -n "${pidfile}" ]; then
		if [ ! -r "${pidfile}" ]; then
			return 3 # Program is not running
		fi

		lpids=`head -n 1 ${pidfile}`
		for pid in ${lpids}
		do
			if [ "${pid}" -ne "$$" -a "${pid}" -ne "${PPID}" ]; then
				kill -0 "${pid}" 2>/dev/null &&
				pidlist="${pidlist} ${pid}"
			fi
			
			if [ "${silent}" != "1" ]; then
				echo "${pidlist}"
			fi

			test -z "${pidlist}" && 
			# Program is dead, pidfile exists
			return 1
			# else
			return 0
		done

	else
		pidlist=`pidof -o $$ -o $PPID -x "$1"`
		if [ "${silent}" != "1" ]; then
			echo "${pidlist}"
		fi

		# Get provide correct running status
		if [ -n "${pidlist}" ]; then
			return 0
		else
			return 3
		fi

	fi

	if [ "$?" != "0" ]; then
		return 3 # Program is not running
	fi
}

# This will ensure compatibility with previous LFS Bootscripts
getpids()
{
	if [ -z "${PIDFILE}" ]; then
		pidofproc -s -p "${PIDFILE}" $@
	else
		pidofproc -s $@
	fi
	base="${1##*/}"
}

#*******************************************************************************
# Function - loadproc [-f] [-n nicelevel] [-p pidfile] pathname [args]
#
# Purpose: This runs the specified program as a daemon
#
# Inputs: -f, run the program even if it is already running
#         -n nicelevel, specifies a nice level. See nice(1).
#         -p pidfile, uses the specified pidfile
#         pathname, pathname to the specified program
#         args, arguments to pass to specified program
#
# Outputs: return 0 - Success
#          return 2 - Invalid of excessive number of arguments, 
#                     warning in stdout
#          return 4 - Program or service status is unknown
#
# Dependencies: nice
#
# Todo: LSB says this should be called start_daemon
#       LSB does not say that it should call evaluate_retval
#       It checks for PIDFILE, which is deprecated.
#         Will be removed after BLFS 6.0
#       loadproc returns 0 if program is already running, not LSB compliant
#
#*******************************************************************************
loadproc()
{
	local pidfile=""
	local forcestart=""
	local nicelevel="10"

# This will ensure compatibility with previous LFS Bootscripts
	if [ -n "${PIDFILE}" ];	then
		pidfile="${PIDFILE}"
	fi

  while true
	do
		case "${1}" in
			-f)
				forcestart="1"
				shift 1
				;;
			-n)
				nicelevel="${2}"
				shift 2
				;;
			-p)
				pidfile="${2}"
				shift 2
				;;
			-*)
				log_failure_msg "Unknown Option: ${1}"
				return 2 #invalid or excess argument(s)
				;;
			*)
				break
				;;
		esac
	done

	if [ "${#}" = "0" ]; then
		log_failure_msg "Usage: loadproc [-f] [-n nicelevel] [-p pidfile] pathname [args]"
		return 2 #invalid or excess argument(s)
	fi

	if [ -z "${forcestart}" ]; then
		if [ -z "${pidfile}" ];	then
			pidofproc -s "${1}"
		else
			pidofproc -s -p "${pidfile}" "${1}"
		fi

		case "${?}" in
			0)
				log_warning_msg "Unable to continue: ${1} is running"
				return 0 # 4
				;;
			1)
				log_warning_msg "Unable to continue: ${pidfile} exists"
				return 0 # 4
				;;
			3)
				;;
			*)
				log_failure_msg "Unknown error code from pidofproc: ${?}"
				return 4
				;;
		esac
	fi

	nice -n "${nicelevel}" "${@}"
	evaluate_retval # This is "Probably" not LSB compliant, but required to be compatible with older bootscripts
	return 0
}

#*******************************************************************************
# Function - killproc  [-p pidfile] pathname [signal]
#
# Purpose:
#
# Inputs: -p pidfile, uses the specified pidfile
#         pathname, pathname to the specified program
#         signal, send this signal to pathname
#
# Outputs: return 0 - Success
#          return 2 - Invalid of excessive number of arguments, 
#                     warning in stdout
#          return 4 - Unknown Status
#
# Dependencies: kill
#
# Todo: LSB does not say that it should call evaluate_retval
#       It checks for PIDFILE, which is deprecated.
#         Will be removed after BLFS 6.0
#
#*******************************************************************************
killproc()
{
	local pidfile=""
	local killsig=TERM # default signal is SIGTERM
	pidlist=""

	# This will ensure compatibility with previous LFS Bootscripts
	if [ -n "${PIDFILE}" ];	then
		pidfile="${PIDFILE}"
	fi

	while true
	do
		case "${1}" in
			-p)
				pidfile="${2}"
				shift 2
				;;
			-*)
				log_failure_msg "Unknown Option: ${1}"
				return 2
				;;
			*)
 				break
				;;
		esac
	done

	if [ "${#}" = "2" ]; then
		killsig="${2}"
	elif [ "${#}" != "1" ];	then
		shift 2
		log_failure_msg "Usage: killproc  [-p pidfile] pathname [signal]"
		return 2
	fi

	# Is the process running?
	if [ -z "${pidfile}" ];	then
		pidofproc -s "${1}"
	else
		pidofproc -s -p "${pidfile}" "${1}"
	fi

    # If running, send the signal
    if [ -n "${pidlist}" ]; then
	for pid in ${pidlist}
	do
		kill -${killsig} ${pid} 2>/dev/null

		# Wait up to 3 seconds, for ${pid} to terminate
		case "${killsig}" in
		TERM|SIGTERM|KILL|SIGKILL)
			# sleep in 1/10ths of seconds and
			# multiply KILLDELAY by 10
			local dtime="${KILLDELAY}0"
			while [ "${dtime}" != "0" ]
			do
				kill -0 ${pid} 2>/dev/null || break
				sleep 0.1
				dtime=$(( ${dtime} - 1))
			done
			# If ${pid} is still running, kill it
			kill -0 ${pid} 2>/dev/null && kill -KILL ${pid} 2>/dev/null
			;;
		esac
	done

	# Check if the process is still running if we tried to stop it
	case "${killsig}" in
	TERM|SIGTERM|KILL|SIGKILL)
		if [ -z "${pidfile}" ];	then
			pidofproc -s "${1}"
		else
			pidofproc -s -p "${pidfile}" "${1}"
		fi

		# Program was terminated
		if [ "$?" != "0" ]; then
			# Remove the pidfile if necessary
			if [ -f "${pidfile}" ];	then
				rm -f "${pidfile}"
			fi
			echo_ok
			return 0
		else # Program is still running
			echo_failure
			return 4 # Unknown Status
		fi
		;;
	*)
		# Just see if the kill returned successfully
		evaluate_retval
		;;
	esac
    else # process not running
	print_status warning not_running
    fi
}


#*******************************************************************************
# Function - log_success_msg "message"
#
# Purpose: Print a success message
#
# Inputs: $@ - Message
#
# Outputs: Text output to screen
#
# Dependencies: echo
#
# Todo: logging
#
#*******************************************************************************
log_success_msg()
{
	${ECHO} -n -e "${BOOTMESG_PREFIX}${@}"
	${ECHO} -e "${SET_COL}""${BRACKET}""[""${SUCCESS}""  OK  ""${BRACKET}""]""${NORMAL}"
	return 0
}

#*******************************************************************************
# Function - log_failure_msg "message"
#
# Purpose: Print a failure message
#
# Inputs: $@ - Message
#
# Outputs: Text output to screen
#
# Dependencies: echo
#
# Todo: logging
#
#*******************************************************************************
log_failure_msg() {
	${ECHO} -n -e "${BOOTMESG_PREFIX}${@}"
	${ECHO} -e "${SET_COL}""${BRACKET}""[""${FAILURE}"" FAIL ""${BRACKET}""]""${NORMAL}"
	return 0
}

#*******************************************************************************
# Function - log_warning_msg "message"
#
# Purpose: print a warning message
#
# Inputs: $@ - Message
#
# Outputs: Text output to screen
#
# Dependencies: echo
#
# Todo: logging
#
#*******************************************************************************
log_warning_msg() {
	${ECHO} -n -e "${BOOTMESG_PREFIX}${@}"
	${ECHO} -e "${SET_COL}""${BRACKET}""[""${WARNING}"" WARN ""${BRACKET}""]""${NORMAL}"
	return 0
}

# End $rc_base/init.d/functions