sgmlid.cxx
Report PUBLIC and SYSTEM Identifiers of SGML Documents
Source: http://inamidst.com/proj/sgmlid/

Installation instructions: 
   1) You'll need SP, which is available from: 

         http://www.jclark.com/sp/

      The current version of which, and the one used in testing sgmlid,
      is available from: 

         ftp://ftp.jclark.com/pub/sp/sp-1.3.4.tar.gz

   2) Untar SP into its own directory, and follow the building
      instructions: you only need to *build* it, not *install* it.
      All you need SP for are the "generic/" and "lib/" directories, 
      and "lib/libsp.a".

   3) Run ./make-sgmlid (from the sgmlid package), giving the directory
      name of your sp build as the first argument. For example: 

         ./make-sgmlid ~/sp-1.3.4

      It should create the binary "sgmlid" for you.

Using sgmlid: 

     ./sgmlid filename

   or

     cat filename | ./sgmlid

Example: 

   $ ./sgmlid test.html 2> /dev/null
   PUBLIC: -//W3C//DTD XHTML 1.0 Strict//EN
   SYSTEM: http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd

Please feel free to send me feedback: 

   http://inamidst.com/sbp/contact

Thanks,

Sean B. Palmer, inamidst.com