I have tried grep -c but that doesnt work either, it keeps on dumping out.

The script is actually a TCL script with embedded UNIX commands. The part its failing on is like so:

set td [exec grep -c "InvalidMessage" $logdir/$t | wc -l]

(I have assigned the variables logdir and t from before)

and i run the script and this occurs:

child process exited abnormally
while executing
"exec grep -c "InvalidMessage" $logdir/$t | wc -l"


It happens because there are no "InvalidMessage" strings in the file, but I know this and want the result i.e. 0 to be assigned to td