src/setvtrgb.c

   1 #include <stdio.h>
   2 #include <stdlib.h>
   3 #include <unistd.h>
   4 #include <getopt.h>
   5 #include <sys/ioctl.h>
   6 #include <linux/kd.h>
   7 #include <errno.h>
   8 #include <error.h>
   9 #include "kbd.h"
  10 #include "getfd.h"
  11 #include "nls.h"
  12 #include "version.h"
  13
  14 static unsigned char *cmap;
  15
  16 /* Standard VGA terminal colors, matching those hardcoded in the Linux kernel's
  17  * drivers/char/vt.c
  18  */
  19 unsigned char vga_colors[] = {
  20         0x00, 0x00, 0x00,
  21         0xaa, 0x00, 0x00,
  22         0x00, 0xaa, 0x00,
  23         0xaa, 0x55, 0x00,
  24         0x00, 0x00, 0xaa,
  25         0xaa, 0x00, 0xaa,
  26         0x00, 0xaa, 0xaa,
  27         0xaa, 0xaa, 0xaa,
  28         0x55, 0x55, 0x55,
  29         0xff, 0x55, 0x55,
  30         0x55, 0xff, 0x55,
  31         0xff, 0xff, 0x55,
  32         0x55, 0x55, 0xff,
  33         0xff, 0x55, 0xff,
  34         0x55, 0xff, 0xff,
  35         0xff, 0xff, 0xff,
  36 };
  37
  38 static void __attribute__ ((noreturn))
  39 usage(int code)
  40 {
  41         fprintf(stderr,
  42                 _("Usage: %s vga|FILE|-\n"
  43                 "\n"
  44                 "If you use the FILE parameter, FILE should be exactly 3 lines of\n"
  45                 "comma-separated decimal values for RED, GREEN, and BLUE.\n"
  46                 "\n"
  47                 "To seed a valid FILE:\n"
  48                 "   cat /sys/module/vt/parameters/default_{red,grn,blu} > FILE\n"
  49                 "\n"
  50                 "and then edit the values in FILE.\n"
  51                 "\n"),
  52                 progname);
  53         exit(code);
  54 }
  55
  56 static void
  57 set_colormap(unsigned char *colormap)
  58 {
  59         int fd = getfd(NULL);
  60
  61         /* Apply the color map to the tty via ioctl */
  62         if (ioctl(fd, PIO_CMAP, colormap) == -1)
  63                 error(EXIT_FAILURE, errno, "ioctl");
  64
  65         close(fd);
  66 }
  67
  68 static void
  69 parse_file(FILE *fd, const char *filename)
  70 {
  71         int c;
  72         unsigned int rows, cols, val;
  73
  74         if ((cmap = calloc(3 * 16, sizeof(unsigned char))) == NULL)
  75                 error(EXIT_FAILURE, errno, "calloc");
  76
  77         for (rows = 0; rows < 3; rows++) {
  78                 cols = 0;
  79
  80                 while (cols < 16) {
  81                         if ((c = fscanf(fd, "%u", &val)) != 1) {
  82                                 if (c == EOF)
  83                                         error(EXIT_FAILURE, errno, "fscanf");
  84
  85                                 error(EXIT_FAILURE, 0, _("Error: %s: Invalid value in field %u in line %u."),
  86                                       filename, rows + 1, cols + 1);
  87                         }
  88
  89                         cmap[rows + cols * 3] = (unsigned char) val;
  90
  91                         if (cols < 15 && fgetc(fd) != ',')
  92                                 error(EXIT_FAILURE, 0, _("Error: %s: Insufficient number of fields in line %u."),
  93                                       filename, rows + 1);
  94                         cols++;
  95                 }
  96
  97                 if ((c = fgetc(fd)) == EOF)
  98                         error(EXIT_FAILURE, 0, _("Error: %s: Line %u has ended unexpectedly.\n"),
  99                               filename, rows + 1);
 100
 101                 if (c != '\n')
 102                         error(EXIT_FAILURE, 0, _("Error: %s: Line %u is too long.\n"),
 103                               filename, rows + 1);
 104         }
 105 }
 106
 107 int
 108 main(int argc, char **argv) {
 109         int c;
 110         const char *file;
 111         FILE *fd;
 112
 113         set_progname(argv[0]);
 114
 115         setlocale(LC_ALL, "");
 116         bindtextdomain(PACKAGE_NAME, LOCALEDIR);
 117         textdomain(PACKAGE_NAME);
 118
 119         while ((c = getopt(argc, argv, "hV")) != EOF) {
 120                 switch (c) {
 121                         case 'V':
 122                                 print_version_and_exit();
 123                                 break;
 124                         case 'h':
 125                                 usage(EXIT_SUCCESS);
 126                                 break;
 127                 }
 128         }
 129
 130         if (optind == argc)
 131                 usage(EXIT_FAILURE);
 132
 133         file = argv[optind];
 134
 135         if (!strcmp(file, "vga")) {
 136                 set_colormap(vga_colors);
 137                 return EXIT_SUCCESS;
 138
 139         } else if (!strcmp(file, "-")) {
 140                 parse_file(stdin, "stdin");
 141
 142         } else {
 143                 if ((fd = fopen(file, "r")) == NULL)
 144                         error(EXIT_FAILURE, errno, "fopen");
 145
 146                 parse_file(fd, file);
 147                 fclose(fd);
 148         }
 149
 150         set_colormap(cmap);
 151         free(cmap);
 152
 153         return EXIT_SUCCESS;
 154 }