diplodocus.org Git - nmh/blob - test/getcwidth.c

   1 /*
   2  * getcwidth - Get the OS's idea of the width of Unicode codepoints
   3  *
   4  * This code is Copyright (c) 2013, by the authors of nmh.  See the
   5  * COPYRIGHT file in the root directory of the nmh distribution for
   6  * complete copyright information.
   7  */
   8
   9 #include <stdio.h>
  10 #include <stdlib.h>
  11 #include <string.h>
  12 #include <errno.h>
  13
  14 #ifdef HAVE_CONFIG_H
  15 #include <config.h>
  16 #endif
  17
  18 #ifdef MULTIBYTE_SUPPORT
  19 #include <locale.h>
  20 #include <wchar.h>
  21 #endif
  22
  23 #ifdef MULTIBYTE_SUPPORT
  24 static void usage(char *);
  25 static void dumpwidth(void);
  26 static void getwidth(const char *);
  27 #endif /* MULTIBYTE_SUPPORT */
  28
  29 int
  30 main(int argc, char *argv[])
  31 {
  32 #ifndef MULTIBYTE_SUPPORT
  33         (void) argc;
  34         (void) argv;
  35         fprintf(stderr, "Nmh was not configured with multibyte support\n");
  36         exit(1);
  37 #else /* MULTIBYTE_SUPPORT */
  38         wchar_t c;
  39         int i;
  40
  41         if (! setlocale(LC_ALL, "")) {
  42                 fprintf(stderr, "setlocale failed, check your LC_ALL, "
  43                     "LC_CTYPE, and LANG environment variables\n");
  44         }
  45
  46         if (argc < 2)
  47                 usage(argv[0]);
  48
  49         if (strcmp(argv[1], "--dump") == 0) {
  50                 if (argc == 2) {
  51                         dumpwidth();
  52                         exit(0);
  53                 } else {
  54                         fprintf(stderr, "--dump cannot be combined with "
  55                                 "other arguments\n");
  56                         exit(1);
  57                 }
  58         }
  59
  60         /*
  61          * Process each argument.  If it begins with "U+", then try to
  62          * convert it to a Unicode codepoint.  Otherwise, take each
  63          * string and get the total width
  64          */
  65
  66         for (i = 1; i < argc; i++) {
  67                 if (strncmp(argv[i], "U+", 2) == 0) {
  68                         /*
  69                          * We're making a big assumption here that
  70                          * wchar_t represents a Unicode codepoint.
  71                          * That technically isn't valid unless the
  72                          * C compiler defines __STDC_ISO_10646__, but
  73                          * we're going to assume now that it works.
  74                          */
  75                         errno = 0;
  76                         c = strtoul(argv[i] + 2, NULL, 16);
  77                         if (errno) {
  78                                 fprintf(stderr, "Codepoint %s invalid\n",
  79                                         argv[i]);
  80                                 continue;
  81                         }
  82                         printf("%d\n", wcwidth(c));
  83                 } else {
  84                         getwidth(argv[i]);
  85                 }
  86         }
  87
  88         exit(0);
  89 }
  90
  91 static void
  92 usage(char *argv0)
  93 {
  94         fprintf(stderr, "Usage: %s [--dump]\n", argv0);
  95         fprintf(stderr, "       %s U+XXXX [...]\n", argv0);
  96         fprintf(stderr, "       %s utf-8-sequence [...]\n", argv0);
  97         fprintf(stderr, "Returns the column width of a Unicode codepoint "
  98                 "or UTF-8 character sequence\n");
  99         fprintf(stderr, "\t--dump\tDump complete width table\n");
 100
 101         exit(1);
 102 }
 103
 104 static void
 105 getwidth(const char *string)
 106 {
 107         wchar_t c;
 108         int charlen, charleft = strlen(string);
 109         int length = 0;
 110
 111         /*
 112          * In theory we should be able to use wcswidth(), but since we're
 113          * testing out how the format libraries behave we'll do it a character
 114          * at a time.
 115          */
 116
 117         if (mbtowc(NULL, NULL, 0)) {}
 118
 119         while (charleft > 0) {
 120                 int clen;
 121
 122                 charlen = mbtowc(&c, string, charleft);
 123
 124                 if (charlen == 0)
 125                         break;
 126
 127                 if (charlen < 0) {
 128                         fprintf(stderr, "Unable to convert string \"%s\"\n",
 129                                 string);
 130                         return;
 131                 }
 132
 133                 if ((clen = wcwidth(c)) < 0) {
 134                         fprintf(stderr, "U+%04lX non-printable\n",
 135                                 (unsigned long int) c);
 136                         return;
 137                 }
 138
 139                 length += clen;
 140                 string += charlen;
 141                 charleft -= charlen;
 142         }
 143
 144         printf("%d\n", length);
 145 }
 146
 147 static void
 148 dumpwidth(void)
 149 {
 150         static struct {
 151                 wchar_t min, max;
 152         } range[] = {
 153                 /* https://en.wikipedia.org/wiki/Unicode#Code_point_planes_and_blocks */
 154                 {  L'\x0000',  L'\xffff' },
 155                 { L'\x10000', L'\x14fff' },
 156                 { L'\x16000', L'\x18fff' },
 157                 { L'\x1b000', L'\x1bfff' },
 158                 { L'\x1d000', L'\x1ffff' },
 159                 { L'\x20000', L'\x2ffff' },
 160                 { L'\xe0000', L'\xe0fff' },
 161                 { L'\0', L'\0' }, /* Terminates list. */
 162         }, *r;
 163         int first;
 164         wchar_t wc, start;
 165         int width, lastwidth;
 166
 167         for (r = range; r->max; r++) {
 168                 first = 1;
 169                 for (wc = r->min; wc <= r->max; wc++) {
 170                         width = wcwidth(wc);
 171                         if (first) {
 172                                 start = wc;
 173                                 lastwidth = width;
 174                                 first = 0;
 175                                 continue;
 176                         }
 177                         if (width != lastwidth) {
 178                                 printf("%04lX - %04lX = %d\n", (unsigned long)start,
 179                                            (unsigned long int)wc - 1, lastwidth);
 180                                 start = wc;
 181                                 lastwidth = width;
 182                         }
 183                         if (wc == r->max)
 184                                 printf("%04lX - %04lX = %d\n", (unsigned long)start,
 185                                            (unsigned long int)wc, lastwidth);
 186                 }
 187         }
 188 #endif /* MULTIBYTE_SUPPORT */
 189 }