lib/color-names.c

   1 /*
   2  * No copyright is claimed.  This code is in the public domain; do with
   3  * it what you wish.
   4  *
   5  * Written by Karel Zak <kzak@redhat.com>
   6  */
   7 #include "c.h"
   8 #include "color-names.h"
   9
  10 #include <ctype.h>
  11
  12 struct ul_color_name {
  13         const char *name;
  14         const char *seq;
  15 };
  16
  17 /*
  18  * qsort/bsearch buddy
  19  */
  20 static int cmp_color_name(const void *a0, const void *b0)
  21 {
  22         const struct ul_color_name
  23                 *a = (const struct ul_color_name *) a0,
  24                 *b = (const struct ul_color_name *) b0;
  25         return strcmp(a->name, b->name);
  26 }
  27
  28 /*
  29  * Maintains human readable color names
  30  */
  31 const char *color_sequence_from_colorname(const char *str)
  32 {
  33         static const struct ul_color_name basic_schemes[] = {
  34                 { "black",      UL_COLOR_BLACK           },
  35                 { "blink",      UL_COLOR_BLINK           },
  36                 { "blue",       UL_COLOR_BLUE            },
  37                 { "bold",       UL_COLOR_BOLD            },
  38                 { "brown",      UL_COLOR_BROWN           },
  39                 { "cyan",       UL_COLOR_CYAN            },
  40                 { "darkgray",   UL_COLOR_DARK_GRAY       },
  41                 { "gray",       UL_COLOR_GRAY            },
  42                 { "green",      UL_COLOR_GREEN           },
  43                 { "halfbright", UL_COLOR_HALFBRIGHT      },
  44                 { "lightblue",  UL_COLOR_BOLD_BLUE       },
  45                 { "lightcyan",  UL_COLOR_BOLD_CYAN       },
  46                 { "lightgray,", UL_COLOR_GRAY            },
  47                 { "lightgreen", UL_COLOR_BOLD_GREEN      },
  48                 { "lightmagenta", UL_COLOR_BOLD_MAGENTA  },
  49                 { "lightred",   UL_COLOR_BOLD_RED        },
  50                 { "magenta",    UL_COLOR_MAGENTA         },
  51                 { "red",        UL_COLOR_RED             },
  52                 { "reset",      UL_COLOR_RESET,          },
  53                 { "reverse",    UL_COLOR_REVERSE         },
  54                 { "yellow",     UL_COLOR_BOLD_YELLOW     },
  55                 { "white",      UL_COLOR_WHITE           }
  56         };
  57         struct ul_color_name key = { .name = str }, *res;
  58
  59         if (!str)
  60                 return NULL;
  61
  62         res = bsearch(&key, basic_schemes, ARRAY_SIZE(basic_schemes),
  63                                 sizeof(struct ul_color_name),
  64                                 cmp_color_name);
  65         return res ? res->seq : NULL;
  66 }
  67
  68
  69 int color_is_sequence(const char *color)
  70 {
  71         if (color && *color == 0x1B) {
  72                 size_t len = strlen(color);
  73
  74                 if (len >= 4 &&
  75                     *(color + 1) == '[' &&
  76                     isdigit(*(color + 2)) &&
  77                     *(color + len - 1) == 'm')
  78                 return 1;
  79         }
  80
  81         return 0;
  82 }
  83
  84 /* canonicalize sequence */
  85 static int __color_canonicalize(const char *str, char **seq)
  86 {
  87         char *in, *out;
  88         int len;
  89
  90         if (!str)
  91                 return -EINVAL;
  92
  93         *seq = NULL;
  94
  95         /* convert color names like "red" to the real sequence */
  96         if (*str != '\\' && isalpha(*str)) {
  97                 const char *s = color_sequence_from_colorname(str);
  98                 *seq = strdup(s ? s : str);
  99
 100                 return *seq ? 0 : -ENOMEM;
 101         }
 102
 103         /* convert xx;yy sequences to "\033[xx;yy" */
 104         if ((len = asprintf(seq, "\033[%sm", str)) < 1)
 105                 return -ENOMEM;
 106
 107         for (in = *seq, out = *seq; in && *in; in++) {
 108                 if (*in != '\\') {
 109                         *out++ = *in;
 110                         continue;
 111                 }
 112                 switch(*(in + 1)) {
 113                 case 'a':
 114                         *out++ = '\a';  /* Bell */
 115                         break;
 116                 case 'b':
 117                         *out++ = '\b';  /* Backspace */
 118                         break;
 119                 case 'e':
 120                         *out++ = '\033';        /* Escape */
 121                         break;
 122                 case 'f':
 123                         *out++ = '\f';  /* Form Feed */
 124                         break;
 125                 case 'n':
 126                         *out++ = '\n';  /* Newline */
 127                         break;
 128                 case 'r':
 129                         *out++ = '\r';  /* Carriage Return */
 130                         break;
 131                 case 't':
 132                         *out++ = '\t';  /* Tab */
 133                         break;
 134                 case 'v':
 135                         *out++ = '\v';  /* Vertical Tab */
 136                         break;
 137                 case '\\':
 138                         *out++ = '\\';  /* Backslash */
 139                         break;
 140                 case '_':
 141                         *out++ = ' ';   /* Space */
 142                         break;
 143                 case '#':
 144                         *out++ = '#';   /* Hash mark */
 145                         break;
 146                 case '?':
 147                         *out++ = '?';   /* Question mark */
 148                         break;
 149                 default:
 150                         *out++ = *in;
 151                         *out++ = *(in + 1);
 152                         break;
 153                 }
 154                 in++;
 155         }
 156
 157         if (out) {
 158                 assert ((out - *seq) <= len);
 159                 *out = '\0';
 160         }
 161
 162         return 0;
 163 }
 164
 165 char *color_get_sequence(const char *color)
 166 {
 167         char *seq = NULL;
 168         int rc = __color_canonicalize(color, &seq);
 169
 170         return rc ? NULL : seq;
 171 }