[syslinux] Issues with syslinux_run_command(str) and parameters

Ady ady-sf at hotmail.com
Tue Apr 29 19:06:55 PDT 2014

> I did confirm earlier that this does work, and combined with a MENU 
> HIDDEN to hide it from the visible menu it is a possible solution. I 
> originally assumed that this was due to that going down a different 
> code path and did not mention it, apologies. The scale of my menu 
> makes doubling/tripling menu entries less ideal, though.  
> Do we consider it intended functionality that modules such as 
> whichsys will not work under ALLOWOPTIONS 0? A strict reading of the 
> wiki would allow for this, as the subsequently loaded module does not 
> have parameters in an append 
> label: http://www.syslinux.org/wiki/index.php/SYSLINUX#ALLOWOPTIONS_fl
> ag_val
> Naturally given my situation here, I think it would be ideal if we 
> could separate disabling user edits & commands from blocking modules 
> loading other modules, etc. :)
> --Ian
Just FYI... You could potentially avoid MENU HIDDEN. A different 
directive, MENU HIDE, might be convenient. It all depends on the 
whole set of cfg files, and on your goals. For example:
 LABEL sys
 LINUX memdisk
 INITRD myimage
 APPEND floppy raw

Regarding "ALLOWOPTIONS 0"...

It is not blocking modules. And this directive can also be used in 
CLI too, without a menu.

In particular, these tests show you that it is not blocking 

You might want to read the meaning of this directive as: "only allow 
LABELs (as-is) to be executed", but that would be slightly 
inaccurate, as any (type of) command can be executed, as long as it 
doesn't need additional arguments.

So, if we use "ALLOWOPTIONS 0", the following command (from CLI) is 
not allowed:
 cat.c32 help.txt

just because "cat.c32" needs an additional argument, a file 

In case we had an entry in the cfg file such as:
 LABEL cat_help
 COM32 cat.c32
 APPEND help.txt

then we could execute the command:

which doesn't need additional arguments.

We could also execute "ls.c32", because it doesn't need additional 

In your example, 'memdisk' requires additional arguments (at least 
the "initrd"). So, if you define a LABEL entry for the exact command, 
you should be able to execute it (by means of the corresponding 


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