Message-ID: <46C6FEDC.5020709@x-ray.at>
Date: Sat, 18 Aug 2007 16:14:52 +0200
From: Reini Urban <rurban@x-ray.at>
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To: cygwin@cygwin.com
Subject: Re: empty PATH, LD_LOAD_PATH default
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Reini Urban schrieb:

Oops! s/LD_LOAD_PATH/LD_LIBRARY_PATH/g of course.

> Reini Urban schrieb:
>> I have a minor compatibility problem.
>>
>> In Linux and other unices it is valid to start a process with an empty 
>> path because the LD_LOAD_PATH is correctly set to resolve the path for 
>> dynamic libraries.
>> I have this situation in perl TAINT-checked environments.
>> Our dll loader cannot handle LD_LOAD_PATH because in the case of 
>> linked shared libs we don't have our own loader, besides doing the 
>> dynamic dlopen.
>>
>> So in linux et al. it is valid to do:
>> $ PATH= ./someprog-with-dependent-so
>> because linux has LD_LOAD_PATH and paths from /etc/ld.so.conf
>> while under cygwin it will fail.
>>
>> Is there some fast way in the environment handling of the startup from 
>> cygwin processes before CreateProcess with a cygwin binary to detect 
>> an empty PATH, to mimic the behaviour of
>>   LD_LOAD_PATH=/usr/bin:$SYSTEMROOT/System32
>> Setting PATH to "/usr/bin/:$SYSTEMROOT:$SYSTEMROOT/System32"
>> to resolve the dll's to please the kernel loader.
> 
> $SYSTEMROOT:$SYSTEMROOT/System32 is not needed, since native windows 
> loads an exe with dll dependencies in $SYSTEMROOT/System32 and empty 
> PATH correctly. Some CreateProcess magic.
> So only some similar /usr/bin magic is required.
> 
>> Or is this a stupid idea? It would make process slower I assume if we 
>> want to detect the dependency of shared libs in processes to be created.
>>
>> I do not know how the situation of an empty PATH in cygwin
>> should be handled.
>> cygcheck does write "WARNING: PATH is not set at all!"
>> Currently the process fails to start, which seems logic, but is a bit 
>> incompatible.


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