标题：chkconfig
Common mode
Format: service <service> 
Print the specified service <service> the command line help. 
Format: service <service> start 
Starts the specified system services <service> 
Format: service <service> stop 
Stop the specified system service <service> 
Format: service <service> restart 
Restart the specified system service <service>, the first stop (stop), and then start (start). 
Format: chkconfig - list 
View list of system services, and operation of each service level. 
Format: chkconfig <service> on 
<service> Designated service set to start automatically when booting. 
Format: chkconfig <service> off 
Set the specified service does not start automatically at boot time <service>. 
Format: ntsysv 
Full-screen text interface to set whether to automatically start services at boot time. 
Use examples
Example a network restartWhen you modify a host name, ip address and other information, the network often need to restart to take effect. 
[Root @ node34 root] # service network 
Usage: / etc / init.d / network {start | stop | restart | reload | status} 
[Root @ node34 root] # service network status 
Configure devices: 
lo eth0 
The current active device: 
lo eth0 
[Root @ node34 root] # service network restart 
Shutting down the interface eth0: [OK] 
Loopback interface: [OK] 
Setting network parameters: [OK] 
Pop-up loopback interface: [OK] 
Pop-up interface eth0: [OK] 
[Root @ node34 root] # 
Example two restart MySQL[Root @ node34 root] # service mysql 
mysql: unrecognized service 
[Root @ node34 root] # service mysqld 
Usage: / etc / init.d / mysqld {start | stop | status | condrestart | restart} 
[Root @ node34 root] # service mysqld status 
mysqld (pid 1638) is running ... 
[Root @ node34 root] # service mysqld restart 
Stop MySQL: [OK] 
Startup MySQL: [determined] 
[Root @ node34 root] # 
Sample source code showing three service script 　　[Root @ web ~] # cat / sbin / service 
#! / Bin / sh 
. / Etc / init.d / functions 
VERSION = "` basename $ 0 `ver. 0.91"
USAGE = "Usage:` basename $ 0 `<option> | - status-all | \ 
[Service_name [command | - full-restart]] " 
SERVICE = 
SERVICEDIR = "/ etc / init.d"
OPTIONS = 
if [$ #-eq 0]; then 
echo "$ {USAGE}"> & 2 
exit 1 
fi 
cd / 
while [$ #-gt 0]; do 
case "$ {1}" in 
- Help |-h | - h *) 
echo "$ {USAGE}"> & 2 
exit 0 
;; 
- Version |-V) 
echo "$ {VERSION}"> & 2 
exit 0 
;; 
*) 
if [-z "$ {SERVICE}"-a $ #-eq 1-a "$ {1}" = "- status-all"]; then 
cd $ {SERVICEDIR} 
for SERVICE in *; do 
case "$ {SERVICE}" in 
functions | halt | killall | single | linuxconf | kudzu) 
;; 
*) 
if! is_ignored_file "$ {SERVICE}" \ 
& & [-X "$ {SERVICEDIR} / $ {SERVICE}"]; then 
env-i LANG = "$ LANG" PATH = "$ PATH" TERM = "$ TERM" "$ {SERVICEDIR} / $ {SERVICE}" status 
fi 
;; 
esac 
done 
exit 0 
elif [$ #-eq 2-a "$ {2}" = "- full-restart"]; then 
SERVICE = "$ {1}" 
if [-x "$ {SERVICEDIR} / $ {SERVICE}"]; then 
env-i LANG = "$ LANG" PATH = "$ PATH" TERM = "$ TERM" "$ {SERVICEDIR} / $ {SERVICE}" stop 
env-i LANG = "$ LANG" PATH = "$ PATH" TERM = "$ TERM" "$ {SERVICEDIR} / $ {SERVICE}" start 
exit $? 
fi 
elif [-z "$ {SERVICE}"]; then 
SERVICE = "$ {1}" 
else 
OPTIONS = "$ {OPTIONS} $ {1}" 
fi 
shift 
;; 
esac 
done 
if [-x "$ {SERVICEDIR} / $ {SERVICE}"]; then 
env-i LANG = "$ LANG" PATH = "$ PATH" TERM = "$ TERM" "$ {SERVICEDIR} / $ {SERVICE}" $ {OPTIONS}
else 
echo $ "$ {SERVICE}: unrecognized service"> & 2 
exit 1 
fi 
[Root @ web ~] # 
Example 4 crond service source[Root @ web init.d] # cat / etc / init.d / crond 
#! / Bin / bash 
# 
# Crond Start / Stop the cron clock daemon. 
# 
# Chkconfig: 2345 90 60
# Description: cron is a standard UNIX program that runs user-specified \ 
# Programs at periodic scheduled times. Vixie cron adds a \ 
# Number of features to the basic UNIX cron, including better \ 
# Security and more powerful configuration options. 
# Processname: crond 
# Config: / etc / crontab 
# Pidfile: / var / run / crond.pid 
# Source function library. 
. / Etc / init.d / functions 
. / Etc / sysconfig / crond 
t = $ {CRON_VALIDATE_MAILRCPTS:-UNSET} 
["$ T"! = "UNSET"] & & export CRON_VALIDATE_MAILRCPTS = "$ t" 
# See how we were called. 
prog = "crond" 
start () { 
echo-n $ "Starting $ prog:" 
if [-e / var / lock / subsys / crond]; then 
if [-e / var / run / crond.pid] & & [-e / proc / `cat / var / run / crond.pid`]; then 
echo-n $ "cannot start crond: crond is already running."; 
failure $ "cannot start crond: crond already running."; 
echo 
return 1 
fi 
fi 
daemon crond $ CRONDARGS 
RETVAL = $? 
echo 
[$ RETVAL-eq 0] & & touch / var / lock / subsys / crond; 
return $ RETVAL 
} 
stop () { 
echo-n $ "Stopping $ prog:" 
if [!-e / var / lock / subsys / crond]; then 
echo-n $ "cannot stop crond: crond is not running." 
failure $ "cannot stop crond: crond is not running." 
echo 
return 1; 
fi 
killproc crond 
RETVAL = $? 
echo 
[$ RETVAL-eq 0] & & rm-f / var / lock / subsys / crond; 
return $ RETVAL 
} 
rhstatus () { 
status crond 
} 
restart () { 
stop 
start 
} 
reload () { 
echo-n $ "Reloading cron daemon configuration:" 
killproc crond-HUP 
RETVAL = $? 
echo 
return $ RETVAL 
} 
case "$ 1" in 
start) 
start 
;; 
stop) 
stop 
;; 
restart) 
restart 
;; 
reload) 
reload 
;; 
status) 
rhstatus 
;; 
condrestart) 
[-F / var / lock / subsys / crond] & & restart | |: 
;; 
*)
echo $ "Usage: $ 0 {start | stop | status | reload | restart | condrestart}" 
exit 1 
esac 
[Root @ web init.d] #