[Jprogramming] How to obtain process status code?

[Jorge Arredondo]

I'm using (2!:0) on Linux to execute a process, if it exits with code
0, I can obtain its output and continue, otherwise an interface error
exception is signaled. Is it possible to execute a process from J on
Linux and get its status code? I tried using (2!:2) but it doesn't
work as it abnormally ends J.

I'm using OpenSuse Linux 10.2 x64 kernel 2.6.18.8-0.9-default (no
mods) and J 6.01

Example:
   (2!:0) 'ls -x'
addons       breaker.ijs  install.txt  jbreak  jconsole    jee
jep          jicon.gif    j.jar        jw      libj601.so  libjnative.so
libjpcre.so  profile.ijs  system       temp    user        version_bin.txt

   (2!:0) 'ls -'
ls: cannot access -: No such file or directory
|interface error
|       (2!:0)'ls -'
   (2!:2) 'ls -x'
*** glibc detected *** ./jconsole: double free or corruption (!prev):
0x00000000008daf90 ***
======= Backtrace: =========
/lib64/libc.so.6[0x2b9b98c268fe]
/lib64/libc.so.6(cfree+0x76)[0x2b9b98c27f36]
/lib64/libc.so.6(fclose+0x155)[0x2b9b98c17a65]
...