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<HTML><HEAD><TITLE>Creating the functions script</TITLE><METANAME="GENERATOR"CONTENT="Modular DocBook HTML Stylesheet Version 1.63"><LINKREL="HOME"TITLE="Linux From Scratch"HREF="../index.html"><LINKREL="UP"TITLE="Creating system boot scripts"HREF="../chapter07/chapter07.html"><LINKREL="PREVIOUS"TITLE="Creating the rcS script"HREF="../chapter07/rcs.html"><LINKREL="NEXT"TITLE="Creating the checkfs script"HREF="../chapter07/checkfs.html"></HEAD><BODYCLASS="sect1"BGCOLOR="#FFFFFF"TEXT="#000000"LINK="#0000FF"VLINK="#840084"ALINK="#0000FF"><DIVCLASS="NAVHEADER"><TABLEWIDTH="100%"BORDER="0"CELLPADDING="0"CELLSPACING="0"><TR><THCOLSPAN="3"ALIGN="center">Linux From Scratch: Version 3.1</TH></TR><TR><TDWIDTH="10%"ALIGN="left"VALIGN="bottom"><AHREF="../chapter07/rcs.html">Prev</A></TD><TDWIDTH="80%"ALIGN="center"VALIGN="bottom">Chapter 7. Creating system boot scripts</TD><TDWIDTH="10%"ALIGN="right"VALIGN="bottom"><AHREF="../chapter07/checkfs.html">Next</A></TD></TR></TABLE><HRALIGN="LEFT"WIDTH="100%"></DIV><DIVCLASS="sect1"><H1CLASS="sect1"><ANAME="ch07-functions">7.6. Creating the functions script</A></H1><P>Create the <TTCLASS="filename">/etc/init.d/functions</TT> script by runningthe following command:</P><P><TABLEBORDER="0"BGCOLOR="#E0E0E0"WIDTH="100%"><TR><TD><FONTCOLOR="#000000"><PRECLASS="screen"><TTCLASS="userinput"><B>cat > /etc/init.d/functions << "EOF"</B></TT>#!/bin/sh# Begin /etc/init.d/functions## Set a few variables that influence the text that's printed on the# screen. The SET_COL variable starts the text in the column number # decided by the COL and WCOL section (as defined by the COL # variable). NORMAL prints text in normal mode.# SUCCESS prints text in a green colour and FAILURE prints text in a red# colour## If COLUMNS hasn't been set yet (bash sets it but not when called as# sh), do it ourself if [ -z "$COLUMNS" ] then # Get the console device if we don't have it already # This is ok by the FHS as there is a fallback if # /usr/bin/tty isn't available, for example at bootup. test -x /usr/bin/tty && CONSOLE=`/usr/bin/tty` test -z "$CONSOLE" && CONSOLE=/dev/console # Get the console size (rows columns) SIZE=$(stty size < $CONSOLE) # Strip off the rows leaving the columns COLUMNS=${SIZE#*\ } fi COL=$[$COLUMNS - 10]WCOL=$[$COLUMNS - 30]SET_COL="echo -en \\033[${COL}G"SET_WCOL="echo -en \\033[${WCOL}G"NORMAL="echo -en \\033[0;39m"SUCCESS="echo -en \\033[1;32m"WARNING="echo -en \\033[1;33m"FAILURE="echo -en \\033[1;31m"## The evaluate_retval function evaluates the return value of the process# that was run just before this function was called. If the return value# was 0, indicating success, the print_status function is called with# the 'success' parameter. Otherwise the print_status function is called# with the failure parameter.#evaluate_retval(){ if [ $? = 0 ] then print_status success else print_status failure fi}## The print_status prints [ OK ] or [FAILED] to the screen. OK appears# in the colour defined by the SUCCESS variable and FAILED appears in# the colour defined by the FAILURE variable. Both are printed starting# in the column defined by the COL variable.#print_status(){## If no parameters are given to the print_status function, print usage# information.# if [ $# = 0 ] then echo "Usage: print_status {success|failure}" return 1 fi case "$1" in success) $SET_COL echo -n "[ " $SUCCESS echo -n "OK" $NORMAL echo " ]" ;; warning) $SET_COL echo -n "[ " $WARNING echo -n "ATTN" $NORMAL echo " ]" ;; failure) $SET_COL echo -n "[" $FAILURE echo -n "FAILED" $NORMAL echo "]" ;; esac}## The loadproc function starts a process (often a daemon) with# proper error checking#loadproc(){## If no parameters are given to the print_status function, print usage# information.# if [ $# = 0 ] then echo "Usage: loadproc {program}" exit 1 fi## Find the basename of the first parameter (the daemon's name without# the path# that was provided so /usr/sbin/syslogd becomes plain 'syslogd' after# basename ran)# base=$(/usr/bin/basename $1)## the pidlist variable will contains the output of the pidof command.# pidof will try to find the PID's that belong to a certain string;# $base in this case# pidlist=$(/bin/pidof -o $$ -o $PPID -o %PPID -x $base) pid="" for apid in $pidlist do if [ -d /proc/$apid ] then pid="$pid $apid" fi done## If the $pid variable contains anything (from the previous for loop) it# means the daemon is already running# if [ ! -n "$pid" ] then## Empty $pid variable means it's not running, so we run "$@" (all# parameters giving to this function from the script) and then check the# return value# "$@" evaluate_retval else## The variable $pid was not empty, meaning it was already running. We'll# print [ ATTN ] now# $SET_WCOL echo -n "Already running" print_status warning fi}## The killproc function kills a process with proper error checking#killproc(){## If no parameters are given to the print_status function, print usage# information.# if [ $# = 0 ] then echo "Usage: killproc {program} [signal]" exit 1 fi## Find the basename of the first parameter (the daemon's name without# the path# that was provided so /usr/sbin/syslogd becomes plain 'syslogd' after# basename ran)# base=$(/usr/bin/basename $1)## Check if we gave a signal to kill the process with (like -HUP, -TERM,# -KILL, etc) to this function (the second parameter). If no second# parameter was provided set the nolevel variable. Else set the# killlevel variable to the value of $2 (the second parameter)# if [ "$2" != "" ] then killlevel=-$2 else nolevel=1 fi## the pidlist variable will contains the output of the pidof command.# pidof will try to find the PID's that belong to a certain string;# $base in this case# pidlist=$(/bin/pidof -o $$ -o $PPID -o %PPID -x $base) pid="" for apid in $pidlist do if [ -d /proc/$apid ] then pid="$pid $apid" fi done## If $pid contains something from the previous for loop it means one or# more PID's were found that belongs to the processes to be killed# if [ -n "$pid" ] then## If no kill level was specified we'll try -TERM first and then sleep# for 2 seconds to allow the kill to be completed# if [ "$nolevel" = 1 ] then /bin/kill -TERM $pid## If after -TERM the PID still exists we'll wait 2 seconds before# trying to kill it with -KILL. If the PID still exist after that, wait# two more seconds. If the PIDs still exist by then it's safe to assume# that we cannot kill these PIDs.# if /bin/ps h $pid >/dev/null 2>&1 then /usr/bin/sleep 2 if /bin/ps h $pid > /dev/null 2>&1 then /bin/kill -KILL $pid if /bin/ps h $pid > /dev/null 2>&1 then /usr/bin/sleep 2 fi fi fi /bin/ps h $pid >/dev/null 2>&1 if [ $? = 0 ] then## If after the -KILL it still exists it can't be killed for some reason# and we'll print [FAILED]# print_status failure else## It was killed, remove possible stale PID file in /var/run and # print [ OK ]# /bin/rm -f /var/run/$base.pid print_status success fi else## A kill level was provided. Kill with the provided kill level and wait# for 2 seconds to allow the kill to be completed# /bin/kill $killlevel $pid if /bin/ps h $pid > /dev/null 2>&1 then /usr/bin/sleep 2 fi /bin/ps h $pid >/dev/null 2>&1 if [ $? = 0 ] then## If ps' return value is 0 it means it ran ok which indicates that the# PID still exists. This means the process wasn't killed properly with# the signal provided. Print [FAILED]# print_status failure else## If the return value was 1 or higher it means the PID didn't exist# anymore which means it was killed successfully. Remove possible stale# PID file and print [ OK ]# /bin/rm -f /var/run/$base.pid print_status success fi fi else## The PID didn't exist so we can't attempt to kill it. Print [ ATTN ]# $SET_WCOL echo -n "Not running" print_status warning fi}## The reloadproc functions sends a signal to a daemon telling it to# reload it's configuration file. This is almost identical to the# killproc function with the exception that it won't try to kill it with# a -KILL signal (aka -9)#reloadproc(){## If no parameters are given to the print_status function, print usage# information.# if [ $# = 0 ] then echo "Usage: reloadproc {program} [signal]" exit 1 fi## Find the basename of the first parameter (the daemon's name without# the path that was provided so /usr/sbin/syslogd becomes plain 'syslogd' # after basename ran)# base=$(/usr/bin/basename $1)## Check if we gave a signal to send to the process (like -HUP)# to this function (the second parameter). If no second# parameter was provided set the nolevel variable. Else set the# killlevel variable to the value of $2 (the second parameter)# if [ -n "$2" ] then killlevel=-$2 else nolevel=1 fi## the pidlist variable will contains the output of the pidof command.# pidof will try to find the PID's that belong to a certain string;# $base in this case# pidlist=$(/bin/pidof -o $$ -o $PPID -o %PPID -x $base) pid="" for apid in $pidlist do if [ -d /proc/$apid ] then pid="$pid $apid" fi done## If $pid contains something from the previous for loop it means one or# more PID's were found that belongs to the processes to be reloaded# if [ -n "$pid" ] then## If nolevel was set we will use the default reload signal SIGHUP.# if [ "$nolevel" = 1 ] then /bin/kill -SIGHUP $pid evaluate_retval else## Else we will use the provided signal# /bin/kill $killlevel $pid evaluate_retval fi else## If $pid is empty no PID's have been found that belong to the process.# Print [ ATTN ]# $SET_WCOL echo -n "Not running" print_status warning fi}## The statusproc function will try to find out if a process is running# or not#statusproc(){## If no parameters are given to the print_status function, print usage# information.# if [ $# = 0 ] then echo "Usage: status {program}" return 1 fi## $pid will contain a list of PID's that belong to a process# pid=$(/bin/pidof -o $$ -o $PPID -o %PPID -x $1) if [ -n "$pid" ] then## If $pid contains something, the process is running, print the contents# of the $pid variable# echo "$1 running with Process ID $pid" return 0 fi## If $pid doesn't contain it check if a PID file exists and inform the# user about this stale file.# if [ -f /var/run/$1.pid ] then pid=$(/usr/bin/head -1 /var/run/$1.pid) if [ -n "$pid" ] then echo "$1 not running but /var/run/$1.pid exists" return 1 fi else echo "$1 is not running" fi}# End /etc/init.d/functions<TTCLASS="userinput"><B>EOF</B></TT></PRE></FONT></TD></TR></TABLE></P></DIV><DIVCLASS="NAVFOOTER"><HRALIGN="LEFT"WIDTH="100%"><TABLEWIDTH="100%"BORDER="0"CELLPADDING="0"CELLSPACING="0"><TR><TDWIDTH="33%"ALIGN="left"VALIGN="top"><AHREF="../chapter07/rcs.html">Prev</A></TD><TDWIDTH="34%"ALIGN="center"VALIGN="top"><AHREF="../index.html">Home</A></TD><TDWIDTH="33%"ALIGN="right"VALIGN="top"><AHREF="../chapter07/checkfs.html">Next</A></TD></TR><TR><TDWIDTH="33%"ALIGN="left"VALIGN="top">Creating the rcS script</TD><TDWIDTH="34%"ALIGN="center"VALIGN="top"><AHREF="../chapter07/chapter07.html">Up</A></TD><TDWIDTH="33%"ALIGN="right"VALIGN="top">Creating the checkfs script</TD></TR></TABLE></DIV></BODY></HTML>⌨️ 快捷键说明
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