Trapping SIGTSTP from /bin/sh

[Roy Mongiovi]

I'm trying to prevent a SIGTSTP from being sent to a shell script with
the command:

trap "" 21

since /usr/include/sys/signal.h #define's SIGTSTP 21, but sh complains:

21: bad trap

Is this just something I'm not supposed to want to do, or doesn't sh
understand the Berkeley signals?

Roy J. Mongiovi     Systems Support Specialist     Office of Computing Services
Georgia Institute of Technology	  Atlanta, Georgia  30332-0275   (404) 894-4660
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	ARPA: roy at prism.gatech.edu