D.2. /etc/rc.d/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"   # 上一级 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
#
# 警告: 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
#
# 依赖关系: - 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

    # Warn about stale pid file
    if [ "$?" = 1 ]; then
        boot_mesg -n "Removing stale pid file: ${pidfile}. " ${WARNING}
        rm -f "${pidfile}"
    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
#
# 依赖关系: pidof, echo, head
#
# Todo: Remove dependency on head
#       This replaces 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
}

#*******************************************************************************
# 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
#
# 依赖关系: nice, rm
#
# 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)
                boot_mesg "Removing stale pid file: ${pidfile}" ${WARNING}
                rm -f "${pidfile}"
                ;;
            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
#
# 依赖关系: kill, rm
#
# 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

    # Remove stale pidfile
    if [ "$?" = 1 ]; then
        boot_mesg "Removing stale pid file: ${pidfile}." ${WARNING}
        rm -f "${pidfile}"
    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
#
# 依赖关系: 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
#
# 依赖关系: 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
#
# 依赖关系: 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