University of Phoenix Material

Systems Administration Scripting Log

From: Your name
Date: mm/dd/yyyy

As you complete each step listed below, keep track of what occurs at each point: what you type and the output given, as well as if you experience any errors.

1. Create a new file called week4.scr

2. Change the permissions on this new file to add the execute bit for user, group, and owner (sudo chmod 755 week4.scr).

3. Edit the file using Gedit

4. Enter the following lines of shell script into the file (just copy and paste):

#!/bin/bash

trap “echo You cannot press THAT key” SIGINT SIGTERM

count=1

echo "Start of week4 script"

while [ $count -le 10 ]

do

echo "Loop #$count"

sleep 5

count=`expr $count + 1`

done

echo "end of the program”

5. Save the file

6. Run the script to make sure you have no syntax errors:

• ./week4.scr

• NOTE: If you have syntax errors, you mistyped something. The script must run with NO syntax errors before you can move on. If you need help, ask.

7. Run the script and verify that you are trapping the SIGINT (signal 2) and SIGTERM (signal 15) signals properly:

• ./week4.scr

• Open a NEW, second Terminal window.

o ps –ef | grep week4.scr

▪ This will obtain the PID of your script

o kill -2 PID

▪ Verify that your trap message is displayed in the FIRST Terminal window

o kill -15 PID

▪ Verify that your trap message is displayed in the FIRST Terminal window

8. Take a screen capture of this sequence (FIRST Terminal window only) and paste it here:

9. Run the script again using the `crontab -e` command to schedule the job in the future. Make it easy on yourself, and schedule the job to run 5 minutes from now.

• crontab –e

o Schedule the week4.scr script to run in approximately five minutes from now. Provide the full path to the script (e.g. /home/path/to/script/week4.scr)

o If we assume that the current time is 11:15 AM, and that you wish to run your script at 11:20 AM, your cron setting would be:

20 11 * * * /home/path/to/script/week4.scr

• After scheduling the job with `crontab -e`, check to see that the job has been scheduled by using the `crontab -l` command from the shell prompt.

• The crontab command will spawn a new shell to run the designated script. This means that the output of the script will NOT be displayed in your current shell, the way it was displayed when you ran the script from the shell prompt.

• The easiest way to verify that your script has run is to redirect standard output (stdout) from the script to a text file. To do this, add the following as the second line of your script:

o exec 1>/home/path/to/script/week4.output.txt

o [Obviously, substitute YOUR path in the command, above]

• After the scheduled execution time has passed, verify the proper execution of the week4.scr script using cron:

o cat week4.output.txt

o Your output should look something like this:

wsaiko@ubuntu:~/POS420/week4$ cat week4.output.txt

Start of week4 script

Loop #1

Loop #2

Loop #3

Loop #4

Loop #5

Loop #6

Loop #7

Loop #8

Loop #9

Loop #10

End of the week4 script

The week4 script has ended Wed Jan 4 13:29:39 PST 2012

• Check the time and date contained in the week4.output.txt file, and verify that the file was written at the scheduled time.

• Capture a screenshot consisting of the `crontab -l` command and its output showing the scheduled job and the `cat` of week4.output.txt following the completion of the script. See the example screenshot on the next page of this document, regarding the required submission format for Screenshot #2.

Sample Output for #9.).

Delete this page when you submit.

-----------------------
These should match, or be 1-5 minutes off, at most, depending on how long your script ran.