lfs-book-zh_CN/bootscripts/contrib/lsb/lib/init-functions

#*******************************************************************************
# Function - start_daemon [-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 or excessive number of arguments, 
#                     warning in stdout
#          return 4 - Program or service status is unknown
#
# Dependencies: nice
#
# Todo: none
#
#*******************************************************************************
start_daemon()
{
  local pidfile=""
	local forcestart=""
	local nicelevel="0"

	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
				;;
			*)
				break
				;;
		esac
	done

	if [ -z "${forcestart}" ]; then
		if [ -z "${pidfile}" ]; then
			pidofproc "${1}" > /dev/null
		else
			pidofproc -p "${pidfile}" "${1}" > /dev/null
		fi

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

	nice -n "${nicelevel}" "${@}"
}

#*******************************************************************************
# 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 1 - Invalid or excessive number of arguments, 
#                     warning in stdout
#          return 4 - Unknown Status
#
# Dependencies: kill
#
# Todo: test
#
#*******************************************************************************
killproc()
{
	local pidfile=""
	local killsig=""
	local pidlist=""
	while true
	do
		case "${1}" in
			-p)
				pidfile="${2}"
				shift 2
				;;
			-*)
				log_failure_msg "Unknown Option: ${1}"
				return 1
				;;
			*)
				break
				;;
		esac
	done

	if [ "${#}" = "2" ]; then
		killsig="${2}"
	elif [ "${#}" != "1" ]; then
		shift 2
		log_failure_msg "Excess Arguments: $@"
		return 1
	fi

	if [ -z "${pidfile}" ]; then
		pidlist=`pidofproc "${1}"`
	else
		pidlist=`pidofproc -p "${pidfile}" "${1}"`
	fi

	for pid in ${pidlist}
	do
		kill -${killsig:-TERM} ${pid} 2> /dev/null
		if [ -z "${killsig}" ]; then
			# Wait up to 3 seconds, for ${pid} to terminate
			local dtime=3
			while [ "${dtime}" != "0" ]
			do
				kill -0 ${pid} 2> /dev/null || break
				sleep 1
				dtime=$(( ${dtime} - 1))
			done
			# If ${pid} is still running, kill it
			kill -0 ${pid} 2> /dev/null && kill -KILL ${pid} 2> /dev/null
		fi
	done

	if [ -z "${killsig}" ]; then
		pidofproc "${1}" 2>&1 > /dev/null
	
		# Program was terminated
		if [ "$?" != "0" ]; then
			# Pidfile Exists
			if [ -f "${pidfile}" ];	then
				rm -f "${pidfile}" 2>&1 > /dev/null
			fi
			return 0
		else # Program is still running
			return 4 # Unknown Status
		fi
	else
		if [ -z "${pidfile}" ]; then
			pidofproc "${1}" 2> /dev/null
		else
			pidofproc -p "${pidfile}" "${1}" 2> /dev/null
		fi
	fi
}

#*******************************************************************************
# Function - pidofproc [-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 - Invalid or excessive number of arguments, 
#                     warning in stdout
#          return 1 - Program is dead, pidfile exists
#          return 3 - Program is not running
#
# Dependencies: pidof, echo
#
# Todo: - Invalid or excessive argments, and program is dead pidfile exists
#         conflict with eachother
#
#*******************************************************************************
pidofproc()
{
	local pidfile=""
	local lpids=""
	local pidlist=""
	while true
	do
		case "${1}" in
			-p)
				pidfile="${2}"
				shift 2
				;;
			-*)
				log_failure_msg "Unknown Option: ${1}"
				return 1
				;;
			*)
				break
				;;
		esac
	done

	if [ "${#}" != "1" ]; then
		shift 1
		log_failure_msg "Excess Arguments: $@"
		return 1
	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
			echo ${pidlist}
			test -z "${pidlist}" && return 1 # Program is dead, pidfile exists
			return 0
		done
		
	else
		pidof "${1}"
	fi

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

# Screen Dimentions
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))

# Set Cursur Position Commands, used via echo -e
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 -e
# Please consult `man console_codes` for more information
# under the "Set Graphics Resolution" 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

BOOTMESG_PREFIX=" * "        # Text at the beginning of every line


#*******************************************************************************
# Function - log_success_msg "message"
#
# Purpose: Print a success message
#
# Inputs:
#
# Outputs:
#
# 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
}