Common mode

Use example(Example a network restart Example two restart MySQL Example 4 crond service source)

chkconfig 功能说明：检查，设置系统的各种服务。

语　法：chkconfig [--add][--del][--list][系统服务] 或 chkconfig [--level <等级代号>][系统服务][on/off/reset]

补充说明：这是Red Hat公司遵循GPL规则所开发的程序，它可查询操作系统在每一个执行等级中会执行哪些系统服务，其中包括各类常驻服务。

chkconfig命令主要用来更新（启动或停止）和查询系统服务的运行级信息。谨记chkconfig不是立即自动禁止或激活一个服务，它只是简单的改变了符号连接。

语法：

chkconfig --list [name]

chkconfig --add name

chkconfig --del name

chkconfig [--level levels] name <on|off|reset>

chkconfig [--level levels] name

chkconfig 没有参数运行时，显示用法。如果加上服务名，那么就检查这个服务是否在当前运行级启动。如果是，返回true，否则返回false。如果在服务名后面指定了on，off或者reset，那么chkconfi 会改变指定服务的启动信息。on和off分别指服务被启动和停止，reset指重置服务的启动信息，无论有问题的初始化脚本指定了什么。on和off开关，系统默认只对运行级3，4，5有效，但是reset可以对所有运行级有效。

--level选项可以指定要查看的运行级而不一定是当前运行级。

--level<等级代号>　指定读系统服务要在哪一个执行等级中开启或关闭。

等级0表示：表示关机

等级1表示：单用户模式

等级2表示：无网络连接的多用户命令行模式

等级3表示：有网络连接的多用户命令行模式

等级4表示：不可用

等级5表示：带图形界面的多用户模式

等级6表示：重新启动

需要说明的是，level选项可以指定要查看的运行级而不一定是当前运行级。对于每个运行级，只能有一个启动脚本或者停止脚本。当切换运行级时，init不会重新启动已经启动的服务，也不会再次去停止已经停止的服务。

chkconfig --list ：显示所有运行级系统服务的运行状态信息（on或off）。如果指定了name，那么只显示指定的服务在不同运行级的状态。

chkconfig --add name：增加一项新的服务。chkconfig确保每个运行级有一项启动(S)或者杀死(K)入口。如有缺少，则会从缺省的init脚本自动建立。

chkconfig --del name：删除所指定的系统服务，不再由chkconfig指令管理，并同时在系统启动的叙述文件内删除相关数据。

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 example

Example a network restart

When 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] #