[asterisk-users] Return code - How to?

[Doug Crompton]

At voip-info.org they show the following example....

exten => s,1,Set(foo=${STAT(s,/var/t3)})

which I guess is suppose to work and make foo = size of t3

I did the following....

exten => 542,1,Set(s1=${STAT(e,"/var/lib/asterisk/t1")})

which should set s1 = 1  if the file exists and 0 if not.

but I get ....

Nov 30 00:19:06 ERROR[23493]: pbx.c:1382 ast_func_read: Function STAT not
registered
    -- Executing Set("SIP/grandstream406-22e9", "s1=0") in new stack

and in general I am confused about return codes. How would you use a
return code from the following....

exten => s,1,System(somescript arg1 arg2)

Can someone give me a working example??? I keep getting the above error

Doug