[gPXE-devel] Script Exit Behaviour

[Shao Miller]

Stefan Hajnoczi wrote:
>
> =Exit=
>
> I think the 'exit' semantics are good.  The 'exit' command allows
> scripts to terminate and will be useful for error handling or stopping
> early.
>

Along with 'exit', we can also keep in mind that gPXE currently "errors 
out" of all executing scripts upon a single command returning an error.  
While 'exit' is a form of control transfer (to the calling script), 
'clear script_errors'[1] allows for a script to continue executing in 
spite of errors.  Since there's no mechanism for checking a command's 
return code yet, this does not allow for error handling as such, but 
does allow users' scripts a little more robustness in the face of 
exceptions.  It's fairly critical, in my opinion, in order to avoid the 
dreaded "manual user intervention required at the console" condition; 
sometimes sites are far away from the user.

- Shao Miller

[1] 
http://git.etherboot.org/?p=people/sha0/gpxe.git;a=commitdiff;h=79bcbbe5c07cb60ee8b240ec0ffff6448f3c42c5