Re: [Ngspice-devel] Spice initialisation file and cygwin

[Steven B. <ste...@di...>]

Hello,

I spotted a bug and a missed a memory leak in my patch to main.c, so  
please use this new patch for main.c instead, along with the other  
patches from my last e-mail.

Regards,
Steven

On 25 Apr 2005, at 22:29, Steven Borley wrote:

> Hello,
>
> I have spotted a problem with the loading of the spice and nutmeg  
> initialisation file on cygwin.
>
> In main.c there is some logic to select the the initialisation file.   
> I believe it goes like this...
>
> For systems that support getpwuid():
> 	Load the standard start up file 'spinit'
> 	Then look for '.spiceinit' in the current directory
> 	If not found look for '.spiceinit' in the users home directory
>
> For systems that do not support getpwuid():
> 	Load the standard start up file 'spinit'
> 	Then look for 'spice.rc' in the current directory
>
> The problem with this is that (at least for Cygwin) getpwuid() uses  
> the /etc/passwd file to determine the users home directory, and for  
> many Cygwin users this is not set in the /etc/passwd file.
>
> The attached patch fixes this, but also subtly changes the logic in a  
> way that I think will be beneficial to others.
>
> The new logic is as follows:
>
> For all systems;
> 	Load the standard start up file 'spinit'
> 	Then look for '.spiceinit' in current directory
> 	If this fails look for 'spice.rc' in currect directory
> 	if this fails the check the HOME environment variable
> 	if HOME is set then:
> 		Look for for '.spiceinit' in user's home directory
> 		If this fails look for 'spice.rc' in user's home directory
>
> The advantage of this is that getpwuid() is not used and getenv() is  
> used to obtain the user's home directory.  I think this is safer and  
> more portable (I see getenv("HOME") being used elsewhere in ngspice  
> without issue).
>
> The second advantage is that spice.rc becomes usable on all systems as  
> an alternative to .spiceinit, thus there is more consistency between  
> platforms.
>
> A possible disadvantage of this is that a .spiceinit file in will  
> override a spice.rc file and this could be confusing to the user given  
> that dot files are often invisible on many platforms.  I chose not to  
> give higher priority to the spice.rc file so as to respect the  
> historic initialisation method, but this is one area I feel unsure  
> about.  It would be easy to modify the new code to reverse or modify  
> this priority.
>
> To implement this change I have added a new static function to main.c  
> called read_initialisation_file() - this is where most of the lower  
> level work is done, and is where I tried to put all the platform  
> dependent conditional macros. The logic (as outline above) is not in  
> this function, but in the body of main() where the original code was.  
> Hopefully this make the code a little more readable (and hence  
> maintainable).
>
> This new code also fixes one small memory leak caused by the use of  
> asprintf().
>
> The header include/defines.h now contains macros for the names of the  
> initialisation files
> and frontend/inp.c and frontend/nutinp.c have been updated to match.
>
> The remaining changes in main.c and some other files do some simple  
> tidying and removing of compile warnings.
>
> Regards,
> Steven
>
> <main.c-diff-2005-04-25-22-14-38.patch><include-diff-2005-04-25-22-16 
> -19.patch><frontend-diff-2005-04-25-22-17-03.patch>