Re: [libextractor] clarification on libextractor functionality and ev

[Christian Grothoff]

On Tuesday, March 29, 2011 11:15:03 pm nijil yes wrote:
> Hi,
> 
> I am a student who is planning to work on Xapian search and indexing
> libraries project.My area of work would be to replace the currect content
> and meta data mechanism , which make use of external filter programs
> resulting in a filter being run for every different file format increasing
> the cpu footprint.I would like to replace these external filter programs
> with shared libraries like the one provided with libextractor.If its not
> too much trouble please clarify on the following matters
> 
> 1:Does it also support to extract content of the file other than just meta
> data ?

In principle this would be possible, but none of the plugins that have been 
implemented do this and this is not the intend of the library.
 
> 2:Does the file format identification and extraction happen implicitly or
> does libextractor implement a mechanism where for each fileformat an
> external filter program is run.If that is the case then there is no need
> to replace the current xapian system with this.

File format identification happens internally; LE runs each plugin and the 
plugin then decides if the given format is applicable to it.  Naturally, most 
plugins terminate quickly after a brief look at the file header most of the 
time.
 
> 3:Is there any fileformats that would be desirable to be seen as a part of
> libextractor but which currently is not a part ?

Always ;-).  There is a TODO list in the distribution.

> 4: Could you suggest any alternative for the above requirements I
> mentioned. I would specifically require c/c++ libaries.

libmime is somewhat related, other than that, I don't know any C/C++ libraries 
doing something similar.

Happy hacking,

Christian