[GSoC] Machine readable output from userland utilities

[Vsevolod Stakhov]

On 20/05/14 17:59, Zaro Korchev wrote:
> I'm working on the project "Machine readable output from userland
> utilities" and I want to share my ideas and thoughts.
> 
> Here is the wiki page of the project: 
> https://wiki.freebsd.org/SummerOfCode2014/MachineReadableFromUserlandUtils
>
>  I'm planning to create a unified output abstraction in the form of a
> library. The tools supporting the machine-readable output feature
> will write output exclusively using the library. The exact output
> format will be customizable. Several backend libraries (like libucl
> and libnv) can be used to implement different formats. Such library
> can either be compiled statically into each application or linked
> dynamically (depending on space/performance/versioning and other
> considerations). Each tool will have to be modified to support the
> new output mechanism. These modifications could trivially be turned
> on and off using a macro switch. One issue that must be considered is
> how to manage long outputs since it may not be possible to store all
> data in memory. This would happen rarely but can still be a problem.
> Probably the easiest way to solve this is to add streamed dumping
> capability into the underlying libraries.
> 
> Do you have any suggestions or ideas?

For libucl output I've used the following approach:
- convert all output objects to ucl;
- write custom emitter for human-readable output.

Perhaps, it might be possible to do it in some unified way, then it is
worth to think about output to:

1) some unified BSD/Posix compatible human readable output
2) libnv output (I'm not sure about arrays, however)
3) xml output (if someone needs it)

-- 
Vsevolod Stakhov