c2html

A tool to add HTML syntax highlighting to C code.

Basicaly you give c2html some C code as input and it classifies all the keywords, identifiers etc using <span> elements, associating them with the appropriate class names. By applying the style.css stylesheet to the generated output, you get the highliting. If you prefer, you can write your own style.

Installation and usage

c2html comes both as a C library and a command-line utility.

Command-line interface

By running build.sh, the c2h executable is built, which is command-line interface of c2html.

You can highlight your C files by doing

./c2h --input file.c --output file.html

This command will generate the highlighted C code.

--no-table

Normally, c2h will generate html using a <table> element, where each line is a <tr> element. This makes the output kind of big. By using the --no-table option, it's possible to generate a more lightweight output where lines are splitted using <br/> elements instead of using a <table>.

You'd use it like this;

./c2h --input file.c --output file.html --no-table

--style

The HTML comes with no styling. If you want to apply a CSS to it, you can provide to c2h a style file using the --style option followed by the name of the file.

./c2h --input file.c --output file.html --style style.css

This will basically add a <style> element with the contents of the style.css file, before the normal HTML output.

Library

The library only exports one function

char *c2html(const char *str, long len, _Bool table_mode, 
             const char *class_prefix, const char **error);

which, given a string containing C code, returns the highlighted version using HTML tags.

For example, lets consider the

/* .. include stdlib.h, string.h and stdio.h .. */
#include "c2html.h"

int main()
{
    _Bool table_mode = 0;
    const char *prefix = NULL;

    char *c = 
      "int main() {\n"
      "  int a = 5;\n"
      "  return 0;\n"
      "}\n";

    char *html = c2html(c, strlen(c), table_mode, prefix, NULL);
    printf("%s\n", html);
    free(html);
    return 0;
}

will output:

<div class="code">
  <div class="code-inner">
    <span class="kword kword-int">int</span> <span class="identifier fdeclname">main</span>() {<br />
    &emsp;&emsp;&emsp;&emsp;<span class="kword kword-int">int</span> <span class="identifier">a</span> <span class="operator">=</span> <span class="val-int">5</span>;<br />
    &emsp;&emsp;&emsp;&emsp;<span class="kword kword-return">return</span> <span class="val-int">0</span>;<br />
    }<br />
  </div>
</div>

if table_mode were 1, then the output would have been:

<div class="code">
  <div class="code-inner">
    <table>
      <tr><td>1</td><td><span class="kword kword-int">int</span> <span class="identifier fdeclname">main</span>() {</td></tr>
      <tr><td>2</td><td>&emsp;&emsp;<span class="kword kword-int">int</span> <span class="identifier">a</span> <span class="operator">=</span> <span class="val-int">5</span>;</td></tr>
      <tr><td>3</td><td>&emsp;&emsp;<span class="kword kword-return">return</span> <span class="val-int">0</span>;</td></tr>
      <tr><td>4</td><td>}</td></tr>
      <tr><td>5</td><td></td></tr>
    </table>
  </div>
</div>