unable to schedule in cron

Shell Programming and Scripting
1

the follwing script is running fine , when run from the ksh shell...it runs properly i.e. waits for a file "test.flag" and sends mail accordingly.

But when I schedule it in the crontab ...it does not run at the specified time (it never runs).
I am using ksh

####shell script starts
count=1
while true; do
if test -f test.flag
then
mailx -s "File Found" s.ba@dsc.com s.ba@hcil.in </man/prd2/bat/tmp/found.txt
exit 0
fi
let count="$count + 1"
#####count=$(( $count + 1 ))
sleep 2
####wait (2)
if [ $count -gt 300 ]
then
mailx -s "File not Found" s.ba@dsc.com s.ba@hcil.in </man/prd2/bat/tmp/not_found.txt
exit 0
fi
done

####shell script ends

###ran crontab -l
20 11 * * * /sa/p/brd/tmp/mailer.sh

##### ran uname -X
System = SunOS
Node = ritba
Release = 5.8
KernelID = Generic_108528-24
Machine = sun4u
BusType = <unknown>
Serial = <unknown>
Users = <unknown>
OEM# = 0
Origin# = 1
NumCPU = 2

Please suggest, (the path of .txt files is correct)

2

As mentioned by you, 'it does not run at the specified time' means it runs after the apecified time or never runs ?

3

Check "man crontab" for the exact location of cron's files on your system.
Please state the unix/Linux version - there is much variation.

In general:
Check /usr/adm/cron/log to see if the job ran at all.
Run "fuser /usr/adm/cron/log" and check there is a process using the log (i.e. cron is running).
Check mail for the user of the cron for error messages.
Check /usr/adm/cron/cron.allow and /usr/adm/cron/cron.deny to make sure that the user is allowed to run a cron.

4

Maybe mailx is not on the path for the cron user?

5

Path is correct ...