Archive for November, 2010

Make GNU PDF manuals: converting texi files to html or pdf

3 Comments
November 24th, 2010 by Albert

All documentation in GNU PDF, as in many other free software projects, is written using texinfo. Texinfo is a documentation format by Richard Stallman and Bob Chassell, which aims to integrate all the project documentation in a unique source, and then produce any desired output document format in an automatic and transparent way. As described in the official page:

Texinfo uses a single source file to produce output in a number of formats, both online and printed (dvi, html, info, pdf, xml, etc.). This means that instead of writing different documents for online information and another for a printed manual, you need write only one document. And when the work is revised, you need revise only that one document.

Several tools and scripts are available from the usual repositories to transform texi files to html or pdf files. In Debian-like systems, they can be installed issuing:

  1. sudo apt-get install texi2html texinfo

This should make available in your system the texi2html and texi2pdf binaries, which you can use to convert texi files into html or pdf files:

  1. cd ~/trunk/doc/
  2. texi2html *.texi
  3. texi2pdf *.texi

Now you can read all GNU PDF manuals in your favourite format. Hope this helps!

Documentation,Free Software,GNU PDF , .

First hacking session with GNU PDF library

4 Comments
November 3rd, 2010 by Albert

In this short session we’ll get running a minimal piece of C code which uses types and functions of the types module, in the base layer of the GNU PDF library. For more information about the GNU PDF library architecture, please go here.

First of all, create a directory to store these little hacking things:

  1. mkdir gnupdfhack
  2. cd gnupdfhack/

Then, create a C test file, and open it with your favorite editor:

  1. touch test.c
  2. emacs test.c

This is a very first approximation to a trivial test unit, which simply:

  • checks the types declared in the library specification, and
  • tries to call some functionalities of the library implementation

The test.c file goes like this:

  1. #include <stdio.h>
  2. #include “../trunk/src/pdf.h”
  3.  
  4. int main ()
  5. {
  6.   printf (“GNU PDF hack test\n”);
  7.  
  8.   pdf_size_t size = 128;
  9.   pdf_error_t *error = NULL;
  10.   pdf_buffer_t *buf = pdf_buffer_new(size, &error);
  11.  
  12.   if (buf == NULL)
  13.     {
  14.       printf(“PDF buffer creation failed\n”);
  15.       /* do some more **error analysis here … */
  16.  
  17.       return 1;
  18.     }
  19.   else
  20.     {
  21.       pdf_buffer_destroy(buf);
  22.       printf(“PDF buffer created and destroyed successfully\n”);
  23.     }
  24.  
  25.   return 0;
  26. }

The type check tries to use the declaration of GNU PDF boolean types, while the library calls essentially allocate space for a buffer, and then they destroy it.

To get it working:

  1. gcc -Wall /usr/local/lib/libgnupdf.so test.c -o test
  2. ./text

This works under the assumption that the GNU PDF library is installed under /usr/local/lib. Please go to this previous post here for a guide on how to install the GNU PDF library in your system. If everything goes well, you’ll get this output:

  1. GNU PDF hack test
  2. —————–
  3. I have the types!
  4. PDF buffer created and destroyed successfully

On further sessions we’ll get more from the actual implementation to make some improvements required on the actual types module. Please feel free to read the base layer interfaces, and happy hacking! Hope this helps!

C library test,Free Software,GNU PDF,Programming , , .