Shell Programming and Scripting

Hi,
Anyone has an idea how to go about this?
Once the below logfile starts populating line by line, I want to send an email alert whenever the following keywords both appears, so users will know that process has started:
"- PROCESS: CHECK_MACH"
"Start -- 09/20/2008 5.25.36PM"

Then the logfile will continue populating, once it reaches this keyword:
"Completion -- 09/20/2008 6.55.47PM"
It will send another email alert to notify process ended.

There will be different process name to scan, i.e. CHECK_MACH, CHECK_DEV, CHECK_SYS, etc. but each process will generate its own separate logfile.

Logfile -->
- APPNAME: MACHQUERY
- TYPE: Device
- PROCESS: CHECK_MACH
- FORMAT: XML
- FILE:
- COUNT: 2
- LOGNAME: AXYRTW_157494
- STATS=0

================================
xxx Checking all logfiles xxx
================================

================================
xxx Detailed results from Run xxx
================================

ExecMacro();
Start -- 09/20/2008 5.25.36PM
The process id = 157494
Starting Process
===============
+ End Status: +Positive+
===============
Ending Process
Completion -- 09/20/2008 6.55.47PM
Closing Process
- Backup step
- QUIT

Well, afaik there are two ways of fixing this:
1) Write another implementation of tail, which take regexps and hook functions to run when the regexps are matched.

I was lazy and went with
2) write a function (I chose bash, I think) which does following

a) Look for linenumber file. If exists, set variable $start to number in file. Else set it to 0.
b) count number of lines in log file, set variable $end with this.
c) using head and tail, read file from line number $start+1 to line number $end , grepping for your regexp(s).
d) If we get a match, send email.
e) write $end to linenumber file.

write the rest of the shell script, which regularly (once a second or whatever) runs the above function.

I chose to save the number of lines in "linenumberfile" since if the watching script should die, we should be able to restart it without getting all the old alarms again.

This should get you started
/fimblo

Not necessary: The existing tail does this just fine:

Code:

tail -f logfile |
 perl -n -e '/^Start/ && mail_function(); /^Finished/ && mail_function();'

Do this for each log file.

Or you can do something like this:

Code:

 perl -e 'open(PIPE,"tail -f $logfile |"); while ($_=<PIPE>) {  ... }'

You can also do all the logfiles at once:

tail -f file1 file2 file3

But then you have to do tricks to make sure that perl knows which process actually started and finished.