summaryrefslogtreecommitdiff
path: root/src/string.cpp
blob: f01786a9739dd29ecdc26308180b79cce66725c4 (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
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
/* $Id$ */

/** @file string.cpp Handling of C-type strings (char*). */

#include "stdafx.h"
#include "debug.h"
#include "core/alloc_func.hpp"
#include "core/math_func.hpp"
#include "string_func.h"

#include "table/control_codes.h"

#include <stdarg.h>
#include <ctype.h> // required for tolower()

/**
 * Safer implementation of vsnprintf; same as vsnprintf except:
 * - last instead of size, i.e. replace sizeof with lastof.
 * - return gives the amount of characters added, not what it would add.
 * @param str    buffer to write to up to last
 * @param last   last character we may write to
 * @param format the formatting (see snprintf)
 * @param ap     the list of arguments for the format
 * @return the number of added characters
 */
static int CDECL vseprintf(char *str, const char *last, const char *format, va_list ap)
{
	if (str >= last) return 0;
	size_t size = last - str;
	return min((int)size, vsnprintf(str, size, format, ap));
}

void ttd_strlcat(char *dst, const char *src, size_t size)
{
	assert(size > 0);
	while (size > 0 && *dst != '\0') {
		size--;
		dst++;
	}

	ttd_strlcpy(dst, src, size);
}


void ttd_strlcpy(char *dst, const char *src, size_t size)
{
	assert(size > 0);
	while (--size > 0 && *src != '\0') {
		*dst++ = *src++;
	}
	*dst = '\0';
}


char *strecat(char *dst, const char *src, const char *last)
{
	assert(dst <= last);
	while (*dst != '\0') {
		if (dst == last) return dst;
		dst++;
	}

	return strecpy(dst, src, last);
}


char *strecpy(char *dst, const char *src, const char *last)
{
	assert(dst <= last);
	while (dst != last && *src != '\0') {
		*dst++ = *src++;
	}
	*dst = '\0';

	if (dst == last && *src != '\0') {
#ifdef STRGEN
		error("String too long for destination buffer");
#else /* STRGEN */
		DEBUG(misc, 0, "String too long for destination buffer");
#endif /* STRGEN */
	}
	return dst;
}


char *CDECL str_fmt(const char *str, ...)
{
	char buf[4096];
	va_list va;

	va_start(va, str);
	int len = vseprintf(buf, lastof(buf), str, va);
	va_end(va);
	char *p = MallocT<char>(len + 1);
	memcpy(p, buf, len + 1);
	return p;
}


void str_validate(char *str, bool allow_newlines, bool ignore)
{
	char *dst = str;
	WChar c;
	size_t len;

	for (len = Utf8Decode(&c, str); c != '\0'; len = Utf8Decode(&c, str)) {
		if (IsPrintable(c) && (c < SCC_SPRITE_START || c > SCC_SPRITE_END)) {
			/* Copy the character back. Even if dst is current the same as str
			 * (i.e. no characters have been changed) this is quicker than
			 * moving the pointers ahead by len */
			do {
				*dst++ = *str++;
			} while (--len != 0);
		} else if (allow_newlines && c == '\n') {
			*dst++ = *str++;
		} else {
			if (allow_newlines && c == '\r' && str[1] == '\n') {
				str += len;
				continue;
			}
			assert(c != '\r');
			/* Replace the undesirable character with a question mark */
			str += len;
			if (!ignore) *dst++ = '?';
		}
	}

	*dst = '\0';
}


void str_strip_colours(char *str)
{
	char *dst = str;
	WChar c;
	size_t len;

	for (len = Utf8Decode(&c, str); c != '\0'; len = Utf8Decode(&c, str)) {
		if (c < SCC_BLUE || c > SCC_BLACK) {
			/* Copy the character back. Even if dst is current the same as str
			 * (i.e. no characters have been changed) this is quicker than
			 * moving the pointers ahead by len */
			do {
				*dst++ = *str++;
			} while (--len != 0);
		} else {
			/* Just skip (strip) the colour codes */
			str += len;
		}
	}
	*dst = '\0';
}

/** Convert a given ASCII string to lowercase.
 * NOTE: only support ASCII characters, no UTF8 fancy. As currently
 * the function is only used to lowercase data-filenames if they are
 * not found, this is sufficient. If more, or general functionality is
 * needed, look to r7271 where it was removed because it was broken when
 * using certain locales: eg in Turkish the uppercase 'I' was converted to
 * '?', so just revert to the old functionality
 * @param str string to convert */
void strtolower(char *str)
{
	for (; *str != '\0'; str++) *str = tolower(*str);
}

/**
 * Only allow certain keys. You can define the filter to be used. This makes
 *  sure no invalid keys can get into an editbox, like BELL.
 * @param key character to be checked
 * @param afilter the filter to use
 * @return true or false depending if the character is printable/valid or not
 */
bool IsValidChar(WChar key, CharSetFilter afilter)
{
	switch (afilter) {
		case CS_ALPHANUMERAL: return IsPrintable(key);
		case CS_NUMERAL:      return (key >= '0' && key <= '9');
		case CS_ALPHA:        return IsPrintable(key) && !(key >= '0' && key <= '9');
	}

	return false;
}

#ifdef WIN32
/* Since version 3.14, MinGW Runtime has snprintf() and vsnprintf() conform to C99 but it's not the case for older versions */
#if (__MINGW32_MAJOR_VERSION < 3) || ((__MINGW32_MAJOR_VERSION == 3) && (__MINGW32_MINOR_VERSION < 14))
int CDECL snprintf(char *str, size_t size, const char *format, ...)
{
	va_list ap;
	int ret;

	va_start(ap, format);
	ret = vsnprintf(str, size, format, ap);
	va_end(ap);
	return ret;
}
#endif /* MinGW Runtime < 3.14 */

#ifdef _MSC_VER
/* *nprintf broken, not POSIX compliant, MSDN description
 * - If len < count, then len characters are stored in buffer, a null-terminator is appended, and len is returned.
 * - If len = count, then len characters are stored in buffer, no null-terminator is appended, and len is returned.
 * - If len > count, then count characters are stored in buffer, no null-terminator is appended, and a negative value is returned
 */
int CDECL vsnprintf(char *str, size_t size, const char *format, va_list ap)
{
	int ret;
	ret = _vsnprintf(str, size, format, ap);
	if (ret < 0 || ret == size) str[size - 1] = '\0';
	return ret;
}
#endif /* _MSC_VER */

#endif /* WIN32 */

/**
 * Safer implementation of snprintf; same as snprintf except:
 * - last instead of size, i.e. replace sizeof with lastof.
 * - return gives the amount of characters added, not what it would add.
 * @param str    buffer to write to up to last
 * @param last   last character we may write to
 * @param format the formatting (see snprintf)
 * @return the number of added characters
 */
int CDECL seprintf(char *str, const char *last, const char *format, ...)
{
	va_list ap;

	va_start(ap, format);
	int ret = vseprintf(str, last, format, ap);
	va_end(ap);
	return ret;
}


/** Convert the md5sum to a hexadecimal string representation
 * @param buf buffer to put the md5sum into
 * @param last last character of buffer (usually lastof(buf))
 * @param md5sum the md5sum itself
 * @return a pointer to the next character after the md5sum */
char *md5sumToString(char *buf, const char *last, const uint8 md5sum[16])
{
	char *p = buf;

	for (uint i = 0; i < 16; i++) {
		p += seprintf(p, last, "%02X", md5sum[i]);
	}

	return p;
}


/* UTF-8 handling routines */


/* Decode and consume the next UTF-8 encoded character
 * @param c Buffer to place decoded character.
 * @param s Character stream to retrieve character from.
 * @return Number of characters in the sequence.
 */
size_t Utf8Decode(WChar *c, const char *s)
{
	assert(c != NULL);

	if (!HasBit(s[0], 7)) {
		/* Single byte character: 0xxxxxxx */
		*c = s[0];
		return 1;
	} else if (GB(s[0], 5, 3) == 6) {
		if (IsUtf8Part(s[1])) {
			/* Double byte character: 110xxxxx 10xxxxxx */
			*c = GB(s[0], 0, 5) << 6 | GB(s[1], 0, 6);
			if (*c >= 0x80) return 2;
		}
	} else if (GB(s[0], 4, 4) == 14) {
		if (IsUtf8Part(s[1]) && IsUtf8Part(s[2])) {
			/* Triple byte character: 1110xxxx 10xxxxxx 10xxxxxx */
			*c = GB(s[0], 0, 4) << 12 | GB(s[1], 0, 6) << 6 | GB(s[2], 0, 6);
			if (*c >= 0x800) return 3;
		}
	} else if (GB(s[0], 3, 5) == 30) {
		if (IsUtf8Part(s[1]) && IsUtf8Part(s[2]) && IsUtf8Part(s[3])) {
			/* 4 byte character: 11110xxx 10xxxxxx 10xxxxxx 10xxxxxx */
			*c = GB(s[0], 0, 3) << 18 | GB(s[1], 0, 6) << 12 | GB(s[2], 0, 6) << 6 | GB(s[3], 0, 6);
			if (*c >= 0x10000 && *c <= 0x10FFFF) return 4;
		}
	}

	//DEBUG(misc, 1, "[utf8] invalid UTF-8 sequence");
	*c = '?';
	return 1;
}


/* Encode a unicode character and place it in the buffer
 * @param buf Buffer to place character.
 * @param c   Unicode character to encode.
 * @return Number of characters in the encoded sequence.
 */
size_t Utf8Encode(char *buf, WChar c)
{
	if (c < 0x80) {
		*buf = c;
		return 1;
	} else if (c < 0x800) {
		*buf++ = 0xC0 + GB(c,  6, 5);
		*buf   = 0x80 + GB(c,  0, 6);
		return 2;
	} else if (c < 0x10000) {
		*buf++ = 0xE0 + GB(c, 12, 4);
		*buf++ = 0x80 + GB(c,  6, 6);
		*buf   = 0x80 + GB(c,  0, 6);
		return 3;
	} else if (c < 0x110000) {
		*buf++ = 0xF0 + GB(c, 18, 3);
		*buf++ = 0x80 + GB(c, 12, 6);
		*buf++ = 0x80 + GB(c,  6, 6);
		*buf   = 0x80 + GB(c,  0, 6);
		return 4;
	}

	//DEBUG(misc, 1, "[utf8] can't UTF-8 encode value 0x%X", c);
	*buf = '?';
	return 1;
}

/**
 * Properly terminate an UTF8 string to some maximum length
 * @param s string to check if it needs additional trimming
 * @param maxlen the maximum length the buffer can have.
 * @return the new length in bytes of the string (eg. strlen(new_string))
 * @NOTE maxlen is the string length _INCLUDING_ the terminating '\0'
 */
size_t Utf8TrimString(char *s, size_t maxlen)
{
	size_t length = 0;

	for (const char *ptr = strchr(s, '\0'); *s != '\0';) {
		size_t len = Utf8EncodedCharLen(*s);
		/* Silently ignore invalid UTF8 sequences, our only concern trimming */
		if (len == 0) len = 1;

		/* Take care when a hard cutoff was made for the string and
		 * the last UTF8 sequence is invalid */
		if (length + len >= maxlen || (s + len > ptr)) break;
		s += len;
		length += len;
	}

	*s = '\0';
	return length;
}

#ifndef _GNU_SOURCE
#include "core/math_func.hpp"
char *strndup(const char *s, size_t len)
{
	len = min(strlen(s), len);
	char *tmp = CallocT<char>(len + 1);
	memcpy(tmp, s, len);
	return tmp;
}
#endif /* !_GNU_SOURCE */

#ifdef DEFINE_STRCASESTR
const char *strcasestr(const char *haystack, const char *needle)
{
	size_t hay_len = strlen(haystack);
	size_t needle_len = strlen(needle);
	while (hay_len >= needle_len) {
		if (strncasecmp(haystack, needle, needle_len) == 0) return haystack;

		haystack++;
		hay_len--;
	}

	return NULL;
}
#endif /* DEFINE_STRCASESTR */