mbeall/crontab.md

## crontab.md

      
    Raw
  

              crontab.md
            
          
    USER is the user's home directory, i.e. queral
PATH


On your team machine, edit the .bashrc file in your home directory.

vi ~/.bashrc


At the bottom of the file, type export PATH=$PATH:~/etc
Save and quit ( :wq )
If it does not already exist create a new directory in your home folder:

mkdir ~/etc


From the command line, type:

source ~/.bashrc
echo $PATH


If you did everything correctly, /home/USER/etc should appear when you echo $PATH

crontab -e (Part 1)


Edit the crontab (crontab -e) so the last two lines look like the following:

# m  h  dom mon dow   command
  *  *  *   *   *     echo "$(whoami): $(date): Hello (Part 1)" >> ~/etc/cron_output.data


Save and quit. Wait a minute, then type cat ~/etc/cron_output.data. It should look like the following:

USER: Mon Dec  8 11:53:01 MST 2014: Hello (Part 1)
USER: Mon Dec  8 11:54:01 MST 2014: Hello (Part 1)


If you see output like shown above, wait 5 minutes, then move on to next step. If you do not, something is wrong.

crontab -e (Part 2)


Create a new script in your ~/etc directory:

vi ~/etc/cron_hello_part2


This file should look like the following:

#!/bin/bash
echo "$(whoami): $(date): Hello (Part 2)" >> ~/etc/cron_output.data


Edit the crontab file (crontab -e), commenting out the line from the previous step and adding a line for the new script.

# m  h  dom mon dow   command
#  *  *  *   *   *     echo "$(whoami): $(date): Hello (Part 1)" >> ~/etc/cron_output.data
  *  *  *   *   *     ~/etc/cron_hello_part2


Wait a minute, then type tail -n5 ~/etc/cron_output.data. It should look like the following:

USER: Mon Dec  8 11:55:01 MST 2014: Hello (Part 1)
USER: Mon Dec  8 11:56:01 MST 2014: Hello (Part 1)
USER: Mon Dec  8 11:57:01 MST 2014: Hello (Part 1)
USER: Mon Dec  8 11:58:01 MST 2014: Hello (Part 2)
USER: Mon Dec  8 11:59:01 MST 2014: Hello (Part 2)


If you see output like shown above, wait 5 minutes, then move on to next step. If you do not, something is wrong.

sudo crontab -e (Part 3)


Edit the system crontab (sudo crontab -e) so the last two lines look like the following:

# m  h  dom mon dow   command
  *  *  *   *   *     echo "$(whoami): $(date): Hello (Part 3)" >> ~USER/etc/cron_output.data


Save and quit. Wait a minute, then type tail -n5 ~USER/etc/cron_output.data. It should look like the following:

USER: Mon Dec  8 11:57:01 MST 2014: Hello (Part 1)
USER: Mon Dec  8 11:58:01 MST 2014: Hello (Part 2)
USER: Mon Dec  8 11:59:01 MST 2014: Hello (Part 2)
USER: Mon Dec  8 12:00:01 MST 2014: Hello (Part 3)
USER: Mon Dec  8 12:01:01 MST 2014: Hello (Part 3)


If you see output like shown above, wait 5 minutes, then move on to next step. If you do not, something is wrong.

sudo crontab -e (Part 4)


Create a new script in your ~/etc directory:

vi ~USER/etc/cron_hello_part4


This file should look like the following:

#!/bin/bash
echo "$(whoami): $(date): Hello (Part 4)" >> ~USER/etc/cron_output.data


Edit the system crontab file (sudo crontab -e), commenting out the line from the previous step and adding a line for the new script.

# m  h  dom mon dow   command
#  *  *  *   *   *     echo "$(whoami): $(date): Hello (Part 3)" >> ~USER/etc/cron_output.data
  *  *  *   *   *     ~USER/etc/cron_hello_part4


Wait a minute, then type tail -n5 ~USER/etc/cron_output.data. It should look like the following:

USER: Mon Dec  8 11:59:01 MST 2014: Hello (Part 2)
USER: Mon Dec  8 12:00:01 MST 2014: Hello (Part 3)
USER: Mon Dec  8 12:01:01 MST 2014: Hello (Part 3)
USER: Mon Dec  8 12:02:01 MST 2014: Hello (Part 4)
USER: Mon Dec  8 12:03:01 MST 2014: Hello (Part 4)


If you see output like shown above, wait 5 minutes, then move on to next step. If you do not, something is wrong.