Add command line interface

[alexeiskachykhin]

Hi guys,

@metafloor @kav @pmn4

Your library looks awesome! I wanted to use it in CI scenario and I though that Command Line Interface would come in handy.

Changes are tested on:

• Windows 10 (Node 4.4.5)
• Ubuntu 14.04 (Node 4.5)

Please consider accepting this PR.

[metafloor]

This looks useful. I will merge the PR most likely this weekend, when I have some time to fully test it. I especially like that you pulled out all the BWIPP options and added descriptions. That will be useful to integrate into the demo and the wiki.

Thanks.

[alexeiskachykhin]

@metafloor sounds great :) please let me know if I can help with anything.

[terryburton]

Mainly aimed at @metafloor but others' comments welcome...

Regarding extracting available options, descriptions, ranges, etc. for each encoder I have it in mind to extend the BWIPP metadata in such a way that frontends can trivially parse out all of the data that they require. The basic idea is that by avoiding embedding static data in the frontends it should be that in many circumstances the user need only freshen their barcode.ps file to benefit from new functionality.

I've raised an issue to track this: bwipp/postscriptbarcode#68

To this end I've created an (unfinished) C library with a trivial API to facilitate options extraction and created bindings (via SWIG) for several languages.

https://github.com/bwipp/postscriptbarcode/tree/master/libs

I've completed the build system and created packaging for .deb, .rpm and Arch distributions so the grunt work is complete, but then I ran out of time/steam before doing the actual design work around the metadata format...

(I wouldn't of course expect that a binding of the metadata parser library for JavaScript would be of any direct use since you discard the barcode.ps in your runtime, but I can imagine that as part of your cross-compile that you might use one of the binding to extract the metadata into a format that is useful to BWIP-JS. Of course if we create a simple but flexible specification for the metadata then using the library in any form isn't required where writing your own parser may be preferable.)

If this sounds like it might be useful then I'll create a wiki page with my current ideas (once I've reminded myself what they are!) that you can comment on and improve.

P.S. Of course please don't let this delay/distract from merging this work. @alexeiskachykhin doesn't deserve the "thanks for the nice work but we'll hold on to this as everything is going to change" bomb - I've been there too many times to count :-)