Shell Programming and Scripting

How can I tell a script to only execute if the other scripts exits successfully?

So "script A" executes and if it executes successfully (0),then "script B" will run

or else

"script A "executes and it exits unsucessfully (1) then "script B" will read return code (1) and will not execute

I have an entry in crontab that run two shell scripts:

the bkscript.sh scripts runs fine (exit code 0)and executes successfully but it will not run the second spacechk.sh script. I can run spacechk.sh manually and all works as designed. It like it not reading the &&, is there a better way to do it?

That should work IF
bkscript.sh returns 0(zero) and only zero.

Chances are that your environment is broken in the cron, and the first script barfs some where.

Do a dummy run like this, just one time use the same user's crontab, then delete it.
test.sh with execute permissions:
crontab -e this entry into cron

Code:

#!/bin/[whatever shell you use goes here]
set > /tmp/set.$$

Code:

* * * * *  /path/to/test.sh

Give it a minute ior two.
crontab -e and remove the test.sh.

Now compare what you have in the /tmp/set[n] file with the expected environment.

Firstly does cron have your environment, a quick check is to source in the local profile for your user.

There are many ways of doing this we'd normally use a token file or the like.

Normally I would put a token in the last line of the log file or in a separate file, then check the token with the following script. You must remember to either create a new logfile or null the logfile at the begining of the first script and you should test that it has done so.

In the first file something like;

Code:

print "Completed Ok" >> ${logfile}

In the following script;

Code:

if
          tail -1 ${logfile} | grep "Completed Ok" | grep -v grep
                then
                      Do Your Bits Here!
                else
                      print "The Backup had a problem - please investigate." >> ${logfile}
fi

This is just one of many ways you could do this, this very simplistic and probably wouldn't be allowed in a production environment. Ensure that any tests that you write are suitable for purpose - key to any of them is testing the result and failing safe!

Regards

Dave

Awesome. Many Thanks

---------- Post updated at 01:25 PM ---------- Previous update was at 01:02 PM ----------

I think I may know why all of this did not work from the begginning using cron:

After taking a look at my bkscript.sh, I had many exit 1 and exit 0 statuses in various places. When the Full or Incremental section of the script is run, I am using an exit 1 , so when bkscript.sh was finished, it had an "1" exit status, so echo $? == 1. Therefore the "&&" would not execute spacechk.sh because of the exit status error within my script was a "1". I have not tested it but I am pretty sure that is what the orginal issue was.

---------- Post updated at 01:32 PM ---------- Previous update was at 01:25 PM ----------

In response to you previous post:

So what you suggested

I could add an entry to a log file:

In the following script;