How can I start and stop a service by using the "service" command, instead of "/etc/init.d/nameofservice start"?

Question

I am starting a service (httpd) by using this command:

/etc/init.d/'name of service' start

How can I start a service by using the command below, if service keyword is not configure for above httpd service?

2)service 'nameofservice' start e.g: service httpd start

How can I configure a service which can start and stop by using service keyword i.e: "service 'nameofservice' start" (service keyword like in option 2) instead of /etc/init.d/nameofservice?

Answer 1

The service(8) command looks for a script in /etc/init.d. If no such script exists, you may need to write your own. On the web you can find guides that will help you do that.

Answer 2

Below script tested in Centos 5. We will create a script that print the current date and time and output directed in to log file and save with name timed.

vim /opt/timed     


 #!/bin/bash 
while true;do
      echo  `date` >> /tmp/timed.log 
done #script finish here below line enable execute permission of script

 chmod +x /opt/timed

Now we will write System V script to start and stop the timed script.

vim /etc/init.d/time (save the script only in /etc/init.d directory only with the name of your choice we use name time here)


  #!/bin/bash  
  # chkconfig: 345 80 20      
  # description: startup script for /opt/timed daemon  
start() {  
nohup /opt/timed &  
}  
stop() {  
pkill timed  
}  
case "$1" in  
             start)   
                   start  #calling the start () function  
             ;;  
             stop)  
                   stop # calling the stop() function
             ;;  
             *)
                   echo "Usage: $0 {start|stop}"  
                   RETVAL=1 #we return the value 1 bcz cmd is not sucessfull  
  esac
  exit 0



 chmod +x /etc/init.d/time  (enabling the execute permission of script)
 service time start    (it will start the script timed)
 ps –ef | grep timed (we can check that script is running with this command)

Explanation of Script

Time script must be in the /etc/init.d directory. chkconfig: 345 80 20 is necessary component of script 345 represent the 3,4 & 5 runlevels. 20 means start command will have the number 20 (S20) in /etc/rc3/ directory. 80 means stop command will have the number 80 (k80) in /etc/rc3/ directory.

start() and stop() are functions for starting and stopping the daemon. When you execute a Unix job in the background (using &, bg command), and logout from the session, your process will get killed. You can avoid this using several methods — executing the job with nohup, or making it as batch job using at, batch or cron command. The PKill command allows you to kill a program simply by specifying the name. $1 takes the first argument. $0 means name of the script. RETVAL is the environment variable that is like exit status of the script if it is 0 script is run successfully and 1 means script not run successfully. If we specify the command other than start or stop then the usage message is printed.