[TIKA-2609] Refine Emacs Lisp file recognition (.elc)

• Type: Improvement
• Status: Open
• Priority: Minor
• Resolution: Unresolved
• Component/s: core
• Assignee: Unassigned
• Reporter: Andreas Meier
• Created: 16/Mar/18 14:28
• Updated: 22/Mar/18 08:00

Description

Some newer .elc files are not recognized properly by the current matcher.
(Tested with emacs 24.4 files from https://github.com/jwiegley/emacs-release/tree/master/lisp)

I created a regex that should handle these files similar to the linux magic:

# Emacs 18 - this is always correct, but not very magical.
0 string \012( Emacs v18 byte-compiled Lisp data
!:mime application/x-elc
# Emacs 19+ - ver. recognition added by Ian Springer
# Also applies to XEmacs 19+ .elc files; could tell them apart with regexs
# - Chris Chittleborough <[e-mail]>
0 string ;ELC
>4 byte >18
>4 byte <32 Emacs/XEmacs v%d byte-compiled Lisp data
!:mime application/x-elc

<mime-type type="application/x-elc">
  <_comment>Emacs Lisp bytecode</_comment>
  <magic priority="50">
    <!-- Emacs 18 -->
    <match value="\012(" type="string" offset="0" />
    <!-- Emacs 19 -->
    <match value=";ELC" type="string" offset="0" >
      <match value="[\\x13-\\x1F]" type="regex" offset="4"/>
    </match>
  </magic>
  <glob pattern="*.elc"/>
</mime-type>

Please verify the hexvalues before committing.

 

Regards

 

Andreas