Wireshark · Ethereal-dev: Re: [Ethereal-dev] MAX_VAR_LEN in prefs.h

[Guy Harris <guy@xxxxxxxxxxxx>]

On Sep 10, 2003, at 4:15 PM, Ian Schorr wrote:

> Why is MAX_VAR_LEN in prefs.h set to 48?  Is there any reason why it  
> can't be set to a larger number, say 256?
>
> (I'm guessing this had something to do with a platform limitation of  
> some kind?)

The platform on which Ethereal's running knows nothing about Ethereal  
preference files, and there are auto char arrays in Ethereal longer  
than 48 characters (i.e., it's not as if there's some platform that  
limits those arrays to 48 bytes or less), so that's not it.

It was originally 32, probably because that was a power of 2 considered  
sufficiently large for preference names, and was boosted to 48 in  
revision 1.28 of prefs.c (it was only recently put in prefs.h, and  
nothing outside of prefs.c uses it, so I'm going to move it back to  
prefs.c), because 32 was too short for  
"gui.protocol_tree_expander_style" if it includes the trailing '\0' -  
why 48?  Why not?

If somebody says they *want* a preference variable with a 256-character  
name, I'm tempted to ask "why?" -  
"ip.treat_the_type_of_service_field_as_if_it_were_a_differentiated_servi 
ces_field_as_specified_in_rfc_2474_and_so_on_rather_than_as_the_type_of_ 
service_field_as_specified_in_rfc_791" seems a bit excessive.