summaryrefslogtreecommitdiff
path: root/gnulib/lib/mbswidth.c
blob: 3c54133a99005e5d31e1c29aecb0de09a58b17b3 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
/* Determine the number of screen columns needed for a string.
   Copyright (C) 2000-2007 Free Software Foundation, Inc.

   This program 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/>.  */

/* Written by Bruno Haible <haible@clisp.cons.org>.  */

#include <config.h>

/* Specification.  */
#include "mbswidth.h"

/* Get MB_CUR_MAX.  */
#include <stdlib.h>

#include <string.h>

/* Get isprint().  */
#include <ctype.h>

/* Get mbstate_t, mbrtowc(), mbsinit(), wcwidth().  */
#include <wchar.h>

/* Get iswcntrl().  */
#include <wctype.h>

#ifndef mbsinit
# if !HAVE_MBSINIT
#  define mbsinit(ps) 1
# endif
#endif

/* Returns the number of columns needed to represent the multibyte
   character string pointed to by STRING.  If a non-printable character
   occurs, and MBSW_REJECT_UNPRINTABLE is specified, -1 is returned.
   With flags = MBSW_REJECT_INVALID | MBSW_REJECT_UNPRINTABLE, this is
   the multibyte analogue of the wcswidth function.
   If STRING is not of length < INT_MAX / 2, integer overflow can occur.  */
int
mbswidth (const char *string, int flags)
{
  return mbsnwidth (string, strlen (string), flags);
}

/* Returns the number of columns needed to represent the multibyte
   character string pointed to by STRING of length NBYTES.  If a
   non-printable character occurs, and MBSW_REJECT_UNPRINTABLE is
   specified, -1 is returned.
   If NBYTES is not < INT_MAX / 2, integer overflow can occur.  */
int
mbsnwidth (const char *string, size_t nbytes, int flags)
{
  const char *p = string;
  const char *plimit = p + nbytes;
  int width;

  width = 0;
#if HAVE_MBRTOWC
  if (MB_CUR_MAX > 1)
    {
      while (p < plimit)
	switch (*p)
	  {
	    case ' ': case '!': case '"': case '#': case '%':
	    case '&': case '\'': case '(': case ')': case '*':
	    case '+': case ',': case '-': case '.': case '/':
	    case '0': case '1': case '2': case '3': case '4':
	    case '5': case '6': case '7': case '8': case '9':
	    case ':': case ';': case '<': case '=': case '>':
	    case '?':
	    case 'A': case 'B': case 'C': case 'D': case 'E':
	    case 'F': case 'G': case 'H': case 'I': case 'J':
	    case 'K': case 'L': case 'M': case 'N': case 'O':
	    case 'P': case 'Q': case 'R': case 'S': case 'T':
	    case 'U': case 'V': case 'W': case 'X': case 'Y':
	    case 'Z':
	    case '[': case '\\': case ']': case '^': case '_':
	    case 'a': case 'b': case 'c': case 'd': case 'e':
	    case 'f': case 'g': case 'h': case 'i': case 'j':
	    case 'k': case 'l': case 'm': case 'n': case 'o':
	    case 'p': case 'q': case 'r': case 's': case 't':
	    case 'u': case 'v': case 'w': case 'x': case 'y':
	    case 'z': case '{': case '|': case '}': case '~':
	      /* These characters are printable ASCII characters.  */
	      p++;
	      width++;
	      break;
	    default:
	      /* If we have a multibyte sequence, scan it up to its end.  */
	      {
		mbstate_t mbstate;
		memset (&mbstate, 0, sizeof mbstate);
		do
		  {
		    wchar_t wc;
		    size_t bytes;
		    int w;

		    bytes = mbrtowc (&wc, p, plimit - p, &mbstate);

		    if (bytes == (size_t) -1)
		      /* An invalid multibyte sequence was encountered.  */
		      {
			if (!(flags & MBSW_REJECT_INVALID))
			  {
			    p++;
			    width++;
			    break;
			  }
			else
			  return -1;
		      }

		    if (bytes == (size_t) -2)
		      /* An incomplete multibyte character at the end.  */
		      {
			if (!(flags & MBSW_REJECT_INVALID))
			  {
			    p = plimit;
			    width++;
			    break;
			  }
			else
			  return -1;
		      }

		    if (bytes == 0)
		      /* A null wide character was encountered.  */
		      bytes = 1;

		    w = wcwidth (wc);
		    if (w >= 0)
		      /* A printable multibyte character.  */
		      width += w;
		    else
		      /* An unprintable multibyte character.  */
		      if (!(flags & MBSW_REJECT_UNPRINTABLE))
			width += (iswcntrl (wc) ? 0 : 1);
		      else
			return -1;

		    p += bytes;
		  }
		while (! mbsinit (&mbstate));
	      }
	      break;
	  }
      return width;
    }
#endif

  while (p < plimit)
    {
      unsigned char c = (unsigned char) *p++;

      if (isprint (c))
	width++;
      else if (!(flags & MBSW_REJECT_UNPRINTABLE))
	width += (iscntrl (c) ? 0 : 1);
      else
	return -1;
    }
  return width;
}