Regarding /proc

[ravi.nanjundappa at ap.sony.com (ravi)]

Hi,
Please havea a look at the following error statement.

# echo attach > /proc/1293/ctl
ctl:Operation not supported 

from where this error message is coming ?
I mean,which is the file that is responsible for checking this file
access permission and displaying the error messages ?

Regards,
N Ravi