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1 /* Determine the number of screen columns needed for a string.
2    Copyright (C) 2000-2005 Free Software Foundation, Inc.
3 
4    This program is free software; you can redistribute it and/or modify
5    it under the terms of the GNU General Public License as published by
6    the Free Software Foundation; either version 2, or (at your option)
7    any later version.
8 
9    This program is distributed in the hope that it will be useful,
10    but WITHOUT ANY WARRANTY; without even the implied warranty of
11    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
12    GNU General Public License for more details.
13 
14    You should have received a copy of the GNU General Public License
15    along with this program; if not, write to the Free Software Foundation,
16    Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.  */
17 
18 /* Written by Bruno Haible <haible@clisp.cons.org>.  */
19 
20 #ifdef HAVE_CONFIG_H
21 # include <config.h>
22 #endif
23 
24 /* Specification.  */
25 #include "mbswidth.h"
26 
27 /* Get MB_CUR_MAX.  */
28 #include <stdlib.h>
29 
30 #include <string.h>
31 
32 /* Get isprint().  */
33 #include <ctype.h>
34 
35 /* Get mbstate_t, mbrtowc(), mbsinit(), wcwidth().  */
36 #if HAVE_WCHAR_H
37 /* Tru64 with Desktop Toolkit C has a bug: <stdio.h> must be included before
38    <wchar.h>.
39    BSD/OS 4.1 has a bug: <stdio.h> and <time.h> must be included before
40    <wchar.h>.  */
41 # include <stdio.h>
42 # include <time.h>
43 # include <wchar.h>
44 #endif
45 
46 /* Get iswprint(), iswcntrl().  */
47 #if HAVE_WCTYPE_H
48 # include <wctype.h>
49 #endif
50 #if !defined iswprint && !HAVE_ISWPRINT
51 # define iswprint(wc) 1
52 #endif
53 #if !defined iswcntrl && !HAVE_ISWCNTRL
54 # define iswcntrl(wc) 0
55 #endif
56 
57 #ifndef mbsinit
58 # if !HAVE_MBSINIT
59 #  define mbsinit(ps) 1
60 # endif
61 #endif
62 
63 #ifndef HAVE_DECL_WCWIDTH
64 "this configure-time declaration test was not run"
65 #endif
66 #if !HAVE_DECL_WCWIDTH
67 int wcwidth ();
68 #endif
69 
70 #ifndef wcwidth
71 # if !HAVE_WCWIDTH
72 /* wcwidth doesn't exist, so assume all printable characters have
73    width 1.  */
74 #  define wcwidth(wc) ((wc) == 0 ? 0 : iswprint (wc) ? 1 : -1)
75 # endif
76 #endif
77 
78 /* Get ISPRINT.  */
79 #if defined (STDC_HEADERS) || (!defined (isascii) && !defined (HAVE_ISASCII))
80 # define IN_CTYPE_DOMAIN(c) 1
81 #else
82 # define IN_CTYPE_DOMAIN(c) isascii(c)
83 #endif
84 /* Undefine to protect against the definition in wctype.h of Solaris 2.6.   */
85 #undef ISPRINT
86 #define ISPRINT(c) (IN_CTYPE_DOMAIN (c) && isprint (c))
87 #undef ISCNTRL
88 #define ISCNTRL(c) (IN_CTYPE_DOMAIN (c) && iscntrl (c))
89 
90 /* Returns the number of columns needed to represent the multibyte
91    character string pointed to by STRING.  If a non-printable character
92    occurs, and MBSW_REJECT_UNPRINTABLE is specified, -1 is returned.
93    With flags = MBSW_REJECT_INVALID | MBSW_REJECT_UNPRINTABLE, this is
94    the multibyte analogue of the wcswidth function.
95    If STRING is not of length < INT_MAX / 2, integer overflow can occur.  */
96 int
mbswidth(const char * string,int flags)97 mbswidth (const char *string, int flags)
98 {
99   return mbsnwidth (string, strlen (string), flags);
100 }
101 
102 /* Returns the number of columns needed to represent the multibyte
103    character string pointed to by STRING of length NBYTES.  If a
104    non-printable character occurs, and MBSW_REJECT_UNPRINTABLE is
105    specified, -1 is returned.
106    If NBYTES is not < INT_MAX / 2, integer overflow can occur.  */
107 int
mbsnwidth(const char * string,size_t nbytes,int flags)108 mbsnwidth (const char *string, size_t nbytes, int flags)
109 {
110   const char *p = string;
111   const char *plimit = p + nbytes;
112   int width;
113 
114   width = 0;
115 #if HAVE_MBRTOWC
116   if (MB_CUR_MAX > 1)
117     {
118       while (p < plimit)
119 	switch (*p)
120 	  {
121 	    case ' ': case '!': case '"': case '#': case '%':
122 	    case '&': case '\'': case '(': case ')': case '*':
123 	    case '+': case ',': case '-': case '.': case '/':
124 	    case '0': case '1': case '2': case '3': case '4':
125 	    case '5': case '6': case '7': case '8': case '9':
126 	    case ':': case ';': case '<': case '=': case '>':
127 	    case '?':
128 	    case 'A': case 'B': case 'C': case 'D': case 'E':
129 	    case 'F': case 'G': case 'H': case 'I': case 'J':
130 	    case 'K': case 'L': case 'M': case 'N': case 'O':
131 	    case 'P': case 'Q': case 'R': case 'S': case 'T':
132 	    case 'U': case 'V': case 'W': case 'X': case 'Y':
133 	    case 'Z':
134 	    case '[': case '\\': case ']': case '^': case '_':
135 	    case 'a': case 'b': case 'c': case 'd': case 'e':
136 	    case 'f': case 'g': case 'h': case 'i': case 'j':
137 	    case 'k': case 'l': case 'm': case 'n': case 'o':
138 	    case 'p': case 'q': case 'r': case 's': case 't':
139 	    case 'u': case 'v': case 'w': case 'x': case 'y':
140 	    case 'z': case '{': case '|': case '}': case '~':
141 	      /* These characters are printable ASCII characters.  */
142 	      p++;
143 	      width++;
144 	      break;
145 	    default:
146 	      /* If we have a multibyte sequence, scan it up to its end.  */
147 	      {
148 		mbstate_t mbstate;
149 		memset (&mbstate, 0, sizeof mbstate);
150 		do
151 		  {
152 		    wchar_t wc;
153 		    size_t bytes;
154 		    int w;
155 
156 		    bytes = mbrtowc (&wc, p, plimit - p, &mbstate);
157 
158 		    if (bytes == (size_t) -1)
159 		      /* An invalid multibyte sequence was encountered.  */
160 		      {
161 			if (!(flags & MBSW_REJECT_INVALID))
162 			  {
163 			    p++;
164 			    width++;
165 			    break;
166 			  }
167 			else
168 			  return -1;
169 		      }
170 
171 		    if (bytes == (size_t) -2)
172 		      /* An incomplete multibyte character at the end.  */
173 		      {
174 			if (!(flags & MBSW_REJECT_INVALID))
175 			  {
176 			    p = plimit;
177 			    width++;
178 			    break;
179 			  }
180 			else
181 			  return -1;
182 		      }
183 
184 		    if (bytes == 0)
185 		      /* A null wide character was encountered.  */
186 		      bytes = 1;
187 
188 		    w = wcwidth (wc);
189 		    if (w >= 0)
190 		      /* A printable multibyte character.  */
191 		      width += w;
192 		    else
193 		      /* An unprintable multibyte character.  */
194 		      if (!(flags & MBSW_REJECT_UNPRINTABLE))
195 			width += (iswcntrl (wc) ? 0 : 1);
196 		      else
197 			return -1;
198 
199 		    p += bytes;
200 		  }
201 		while (! mbsinit (&mbstate));
202 	      }
203 	      break;
204 	  }
205       return width;
206     }
207 #endif
208 
209   while (p < plimit)
210     {
211       unsigned char c = (unsigned char) *p++;
212 
213       if (ISPRINT (c))
214 	width++;
215       else if (!(flags & MBSW_REJECT_UNPRINTABLE))
216 	width += (ISCNTRL (c) ? 0 : 1);
217       else
218 	return -1;
219     }
220   return width;
221 }
222