Hi all,

On WebFaction, my Linux shared hosting server, I created a simple "Hello, World!" script in a file named "hello.d".

Attempting to run the script with "rdmd hello.d" yielded no error messages, and strangely, no output.

However, the following works, and I see the output:

(1) dmd hello.d
(2) ./hello

Running "rdmd --chatty hellod.d" shows D writing some files to /tmp folder and calling exec on the final temp file.

I suspect the reason I'm not seeing any output using rdmd has something to do with WebFaction's security policies disallowing any execution on files in the /tmp folder.

May I request that rdmd check, say, the environment variables tmp or temp for the path to write the temporary files in?

Thanks!

Am Sun, 31 Aug 2014 09:01:23 +0000
schrieb "David Chin" <dlcmhd@me.com>:

> Hi all,
> 
> On WebFaction, my Linux shared hosting server, I created a simple "Hello, World!" script in a file named "hello.d".
> 
> Attempting to run the script with "rdmd hello.d" yielded no error messages, and strangely, no output.
> 
> However, the following works, and I see the output:
> 
> (1) dmd hello.d
> (2) ./hello
> 
> Running "rdmd --chatty hellod.d" shows D writing some files to /tmp folder and calling exec on the final temp file.
> 
> I suspect the reason I'm not seeing any output using rdmd has something to do with WebFaction's security policies disallowing any execution on files in the /tmp folder.
> 
> May I request that rdmd check, say, the environment variables tmp or temp for the path to write the temporary files in?
> 
> Thanks!

Sorry for hijacking. I believe any program should remove what it placed in /tmp on exit and actively manage any cached files under /var/lib, e.g. by age or size of the cache. In the case of rdmd, I'd even prefer to just do what most native compilers do and place object files alongside the sources, but allow custom object file directories. Usually I wouldn't say anything, because endless bike-shedding ensues, but it looks like now there is a technical argument, too. :p

-- 
Marco

On Sunday, 31 August 2014 at 09:51:13 UTC, Marco Leise wrote:
> Am Sun, 31 Aug 2014 09:01:23 +0000
> schrieb "David Chin" <dlcmhd@me.com>:
>
>> Hi all,
>> 
>> On WebFaction, my Linux shared hosting server, I created a simple "Hello, World!" script in a file named "hello.d".
>> 
>> Attempting to run the script with "rdmd hello.d" yielded no error messages, and strangely, no output.
>> 
>> However, the following works, and I see the output:
>> 
>> (1) dmd hello.d
>> (2) ./hello
>> 
>> Running "rdmd --chatty hellod.d" shows D writing some files to /tmp folder and calling exec on the final temp file.
>> 
>> I suspect the reason I'm not seeing any output using rdmd has something to do with WebFaction's security policies disallowing any execution on files in the /tmp folder.
>> 
>> May I request that rdmd check, say, the environment variables tmp or temp for the path to write the temporary files in?
>> 
>> Thanks!
>
> Sorry for hijacking. I believe any program should remove what
> it placed in /tmp on exit and actively manage any cached files
> under /var/lib, e.g. by age or size of the cache. In the case
> of rdmd, I'd even prefer to just do what most native compilers
> do and place object files alongside the sources, but allow
> custom object file directories. Usually I wouldn't say
> anything, because endless bike-shedding ensues, but it looks
> like now there is a technical argument, too. :p

There are some other technical arguments, too, but it looks like they speak against /var/lib:

* Permissions: /var/lib is not world-writable; there would either need to be a new world-writable directory below it (bad practice), or rdmd would have to run as setuid with a dedicated user. That's not a good idea either, because users would then have access to other users' binaries.
* Similarly, you don't want to store the binaries next to the sources if those are in /usr/bin, for example.
* /tmp is often cleaned regularly. But maybe /var/tmp would be more appropriate than /tmp.

About the original post: While the cause of the problem seems clear in your case, rdmd also doesn't print anything when the compiled program segfaults. This could be another candidate for the observed behaviour.