process-rgb-color.c

/*** file process-rgb-color.c from https://github.com/bstarynk/misc-basile/ ***/
/*** SPDX-License-Identifier: GPLv3+ ***/

/*******************************************************************************
 * © Copyright 2024 Basile STARYNKEVITCH (France)
 * email <basile@starynkevitch.net>
 * License: GPLv3+ (file COPYING-GPLv3)
 *    This software is free software: you can redistribute it and/or modify
 *    it under the terms of the GNU General Public License as published by
 *    the Free Software Foundation, either version 3 of the License, or
 *    (at your option) any later version.
 *    This program is distributed in the hope that it will be useful,
 *    but WITHOUT ANY WARRANTY; without even the implied warranty of
 *    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *    GNU General Public License for more details.
 *
 *    You should have received a copy of the GNU General Public License
 *    along with this program.  If not, see <http://www.gnu.org/licenses/>.
 *
 ******************************************************************************/

#include <stdio.h>
#include <stdlib.h>
#include <errno.h>
#include <string.h>
#include <unistd.h>

char *progname;
int
main (int argc, char **argv)
{
  char linebuf[128];
  char colorbuf[80];
  progname = argv[0];
  if (argc > 1 && !strcmp (argv[1], "--help"))
    {
      printf
	("%s: process the /etc/X11/rgb.txt file and emit on stdout C macro expressions\n"
	 "RPS_RGB_COLOR(Red,Green,Blue,\"colorname\");\n", progname);
      return 0;
    }
  char *rgbfilename = "/etc/X11/rgb.txt";
  if (argc > 1 && !access (argv[1], R_OK))
    rgbfilename = argv[1];
  FILE *rgbf = fopen (rgbfilename, "r");
  if (!rgbf)
    {
      fprintf (stderr, "%s: cannot fopen %s - %s\n", progname, rgbfilename,
	       strerror (errno));
      exit (EXIT_FAILURE);
    };
  int nbcolors = 0;
  int widestcolor = 0;
  do
    {
      memset (linebuf, 0, sizeof (linebuf));
      memset (colorbuf, 0, sizeof (colorbuf));
      if (!fgets (linebuf, sizeof (linebuf) - 4, rgbf))
	break;
      int r = 0, g = 0, b = 0, i = 0;
      if (sscanf (linebuf, "%d %d %d %64[A-Za-z0-9 ]%n",
		  &r, &g, &b, colorbuf, &i) <= 3)
	continue;
      if (widestcolor < (int) strlen (colorbuf))
	widestcolor = (int) strlen (colorbuf);
      nbcolors++;
      printf ("RPS_RGB_COLOR(%3d,%3d,%3d,\"%s\")\n", r, g, b, colorbuf);
    }
  while (!feof (rgbf));
  printf ("#define RPS_NB_RGB_COLORS %d\n", nbcolors);
  printf ("#define RPS_WIDEST_RGB_COLOR %d /*bytes*/\n", widestcolor);
  printf ("/// end of colors\n");
  return 0;
}