1 /* Determine the number of screen columns needed for a string.
2 Copyright (C) 2000-2006 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 #include <config.h>
21
22 /* Specification. */
23 #include "mbswidth.h"
24
25 /* Get MB_CUR_MAX. */
26 #include <stdlib.h>
27
28 #include <string.h>
29
30 /* Get isprint(). */
31 #include <ctype.h>
32
33 /* Get mbstate_t, mbrtowc(), mbsinit(). */
34 #if HAVE_WCHAR_H
35 /* Tru64 with Desktop Toolkit C has a bug: <stdio.h> must be included before
36 <wchar.h>.
37 BSD/OS 4.1 has a bug: <stdio.h> and <time.h> must be included before
38 <wchar.h>. */
39 # include <stdio.h>
40 # include <time.h>
41 # include <wchar.h>
42 #endif
43
44 /* Get wcwidth(). */
45 #include "wcwidth.h"
46
47 /* Get iswcntrl(). */
48 #if HAVE_WCTYPE_H
49 # include <wctype.h>
50 #endif
51 #if !defined iswcntrl && !HAVE_ISWCNTRL
52 # define iswcntrl(wc) (((wc) & ~0x1f) == 0 || (wc) == 0x7f)
53 #endif
54
55 #ifndef mbsinit
56 # if !HAVE_MBSINIT
57 # define mbsinit(ps) 1
58 # endif
59 #endif
60
61 /* Returns the number of columns needed to represent the multibyte
62 character string pointed to by STRING. If a non-printable character
63 occurs, and MBSW_REJECT_UNPRINTABLE is specified, -1 is returned.
64 With flags = MBSW_REJECT_INVALID | MBSW_REJECT_UNPRINTABLE, this is
65 the multibyte analogue of the wcswidth function.
66 If STRING is not of length < INT_MAX / 2, integer overflow can occur. */
67 int
mbswidth(const char * string,int flags)68 mbswidth (const char *string, int flags)
69 {
70 return mbsnwidth (string, strlen (string), flags);
71 }
72
73 /* Returns the number of columns needed to represent the multibyte
74 character string pointed to by STRING of length NBYTES. If a
75 non-printable character occurs, and MBSW_REJECT_UNPRINTABLE is
76 specified, -1 is returned.
77 If NBYTES is not < INT_MAX / 2, integer overflow can occur. */
78 int
mbsnwidth(const char * string,size_t nbytes,int flags)79 mbsnwidth (const char *string, size_t nbytes, int flags)
80 {
81 const char *p = string;
82 const char *plimit = p + nbytes;
83 int width;
84
85 width = 0;
86 #if HAVE_MBRTOWC
87 if (MB_CUR_MAX > 1)
88 {
89 while (p < plimit)
90 switch (*p)
91 {
92 case ' ': case '!': case '"': case '#': case '%':
93 case '&': case '\'': case '(': case ')': case '*':
94 case '+': case ',': case '-': case '.': case '/':
95 case '0': case '1': case '2': case '3': case '4':
96 case '5': case '6': case '7': case '8': case '9':
97 case ':': case ';': case '<': case '=': case '>':
98 case '?':
99 case 'A': case 'B': case 'C': case 'D': case 'E':
100 case 'F': case 'G': case 'H': case 'I': case 'J':
101 case 'K': case 'L': case 'M': case 'N': case 'O':
102 case 'P': case 'Q': case 'R': case 'S': case 'T':
103 case 'U': case 'V': case 'W': case 'X': case 'Y':
104 case 'Z':
105 case '[': case '\\': case ']': case '^': case '_':
106 case 'a': case 'b': case 'c': case 'd': case 'e':
107 case 'f': case 'g': case 'h': case 'i': case 'j':
108 case 'k': case 'l': case 'm': case 'n': case 'o':
109 case 'p': case 'q': case 'r': case 's': case 't':
110 case 'u': case 'v': case 'w': case 'x': case 'y':
111 case 'z': case '{': case '|': case '}': case '~':
112 /* These characters are printable ASCII characters. */
113 p++;
114 width++;
115 break;
116 default:
117 /* If we have a multibyte sequence, scan it up to its end. */
118 {
119 mbstate_t mbstate;
120 memset (&mbstate, 0, sizeof mbstate);
121 do
122 {
123 wchar_t wc;
124 size_t bytes;
125 int w;
126
127 bytes = mbrtowc (&wc, p, plimit - p, &mbstate);
128
129 if (bytes == (size_t) -1)
130 /* An invalid multibyte sequence was encountered. */
131 {
132 if (!(flags & MBSW_REJECT_INVALID))
133 {
134 p++;
135 width++;
136 break;
137 }
138 else
139 return -1;
140 }
141
142 if (bytes == (size_t) -2)
143 /* An incomplete multibyte character at the end. */
144 {
145 if (!(flags & MBSW_REJECT_INVALID))
146 {
147 p = plimit;
148 width++;
149 break;
150 }
151 else
152 return -1;
153 }
154
155 if (bytes == 0)
156 /* A null wide character was encountered. */
157 bytes = 1;
158
159 w = wcwidth (wc);
160 if (w >= 0)
161 /* A printable multibyte character. */
162 width += w;
163 else
164 /* An unprintable multibyte character. */
165 if (!(flags & MBSW_REJECT_UNPRINTABLE))
166 width += (iswcntrl (wc) ? 0 : 1);
167 else
168 return -1;
169
170 p += bytes;
171 }
172 while (! mbsinit (&mbstate));
173 }
174 break;
175 }
176 return width;
177 }
178 #endif
179
180 while (p < plimit)
181 {
182 unsigned char c = (unsigned char) *p++;
183
184 if (isprint (c))
185 width++;
186 else if (!(flags & MBSW_REJECT_UNPRINTABLE))
187 width += (iscntrl (c) ? 0 : 1);
188 else
189 return -1;
190 }
191 return width;
192 }
193