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1 /*
2  * Copyright (c) 2000, 2001, 2002 Fabrice Bellard
3  * Copyright (c) 2007 Mans Rullgard
4  *
5  * This file is part of FFmpeg.
6  *
7  * FFmpeg is free software; you can redistribute it and/or
8  * modify it under the terms of the GNU Lesser General Public
9  * License as published by the Free Software Foundation; either
10  * version 2.1 of the License, or (at your option) any later version.
11  *
12  * FFmpeg is distributed in the hope that it will be useful,
13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
15  * Lesser General Public License for more details.
16  *
17  * You should have received a copy of the GNU Lesser General Public
18  * License along with FFmpeg; if not, write to the Free Software
19  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
20  */
21 
22 #include <limits.h>
23 #include <stdarg.h>
24 #include <stdint.h>
25 #include <stdio.h>
26 #include <string.h>
27 
28 #include "config.h"
29 #include "mem.h"
30 #include "avassert.h"
31 #include "avstring.h"
32 #include "bprint.h"
33 #include "error.h"
34 #include "macros.h"
35 #include "version.h"
36 
av_strstart(const char * str,const char * pfx,const char ** ptr)37 int av_strstart(const char *str, const char *pfx, const char **ptr)
38 {
39     while (*pfx && *pfx == *str) {
40         pfx++;
41         str++;
42     }
43     if (!*pfx && ptr)
44         *ptr = str;
45     return !*pfx;
46 }
47 
av_stristart(const char * str,const char * pfx,const char ** ptr)48 int av_stristart(const char *str, const char *pfx, const char **ptr)
49 {
50     while (*pfx && av_toupper((unsigned)*pfx) == av_toupper((unsigned)*str)) {
51         pfx++;
52         str++;
53     }
54     if (!*pfx && ptr)
55         *ptr = str;
56     return !*pfx;
57 }
58 
av_stristr(const char * s1,const char * s2)59 char *av_stristr(const char *s1, const char *s2)
60 {
61     if (!*s2)
62         return (char*)(intptr_t)s1;
63 
64     do
65         if (av_stristart(s1, s2, NULL))
66             return (char*)(intptr_t)s1;
67     while (*s1++);
68 
69     return NULL;
70 }
71 
av_strnstr(const char * haystack,const char * needle,size_t hay_length)72 char *av_strnstr(const char *haystack, const char *needle, size_t hay_length)
73 {
74     size_t needle_len = strlen(needle);
75     if (!needle_len)
76         return (char*)haystack;
77     while (hay_length >= needle_len) {
78         hay_length--;
79         if (!memcmp(haystack, needle, needle_len))
80             return (char*)haystack;
81         haystack++;
82     }
83     return NULL;
84 }
85 
av_strlcpy(char * dst,const char * src,size_t size)86 size_t av_strlcpy(char *dst, const char *src, size_t size)
87 {
88     size_t len = 0;
89     while (++len < size && *src)
90         *dst++ = *src++;
91     if (len <= size)
92         *dst = 0;
93     return len + strlen(src) - 1;
94 }
95 
av_strlcat(char * dst,const char * src,size_t size)96 size_t av_strlcat(char *dst, const char *src, size_t size)
97 {
98     size_t len = strlen(dst);
99     if (size <= len + 1)
100         return len + strlen(src);
101     return len + av_strlcpy(dst + len, src, size - len);
102 }
103 
av_strlcatf(char * dst,size_t size,const char * fmt,...)104 size_t av_strlcatf(char *dst, size_t size, const char *fmt, ...)
105 {
106     size_t len = strlen(dst);
107     va_list vl;
108 
109     va_start(vl, fmt);
110     len += vsnprintf(dst + len, size > len ? size - len : 0, fmt, vl);
111     va_end(vl);
112 
113     return len;
114 }
115 
av_asprintf(const char * fmt,...)116 char *av_asprintf(const char *fmt, ...)
117 {
118     char *p = NULL;
119     va_list va;
120     int len;
121 
122     va_start(va, fmt);
123     len = vsnprintf(NULL, 0, fmt, va);
124     va_end(va);
125     if (len < 0)
126         goto end;
127 
128     p = av_malloc(len + 1);
129     if (!p)
130         goto end;
131 
132     va_start(va, fmt);
133     len = vsnprintf(p, len + 1, fmt, va);
134     va_end(va);
135     if (len < 0)
136         av_freep(&p);
137 
138 end:
139     return p;
140 }
141 
142 #if FF_API_D2STR
av_d2str(double d)143 char *av_d2str(double d)
144 {
145     char *str = av_malloc(16);
146     if (str)
147         snprintf(str, 16, "%f", d);
148     return str;
149 }
150 #endif
151 
152 #define WHITESPACES " \n\t\r"
153 
av_get_token(const char ** buf,const char * term)154 char *av_get_token(const char **buf, const char *term)
155 {
156     char *out     = av_realloc(NULL, strlen(*buf) + 1);
157     char *ret     = out, *end = out;
158     const char *p = *buf;
159     if (!out)
160         return NULL;
161     p += strspn(p, WHITESPACES);
162 
163     while (*p && !strspn(p, term)) {
164         char c = *p++;
165         if (c == '\\' && *p) {
166             *out++ = *p++;
167             end    = out;
168         } else if (c == '\'') {
169             while (*p && *p != '\'')
170                 *out++ = *p++;
171             if (*p) {
172                 p++;
173                 end = out;
174             }
175         } else {
176             *out++ = c;
177         }
178     }
179 
180     do
181         *out-- = 0;
182     while (out >= end && strspn(out, WHITESPACES));
183 
184     *buf = p;
185 
186     char *small_ret = av_realloc(ret, out - ret + 2);
187     return small_ret ? small_ret : ret;
188 }
189 
av_strtok(char * s,const char * delim,char ** saveptr)190 char *av_strtok(char *s, const char *delim, char **saveptr)
191 {
192     char *tok;
193 
194     if (!s && !(s = *saveptr))
195         return NULL;
196 
197     /* skip leading delimiters */
198     s += strspn(s, delim);
199 
200     /* s now points to the first non delimiter char, or to the end of the string */
201     if (!*s) {
202         *saveptr = NULL;
203         return NULL;
204     }
205     tok = s++;
206 
207     /* skip non delimiters */
208     s += strcspn(s, delim);
209     if (*s) {
210         *s = 0;
211         *saveptr = s+1;
212     } else {
213         *saveptr = NULL;
214     }
215 
216     return tok;
217 }
218 
av_strcasecmp(const char * a,const char * b)219 int av_strcasecmp(const char *a, const char *b)
220 {
221     uint8_t c1, c2;
222     do {
223         c1 = av_tolower(*a++);
224         c2 = av_tolower(*b++);
225     } while (c1 && c1 == c2);
226     return c1 - c2;
227 }
228 
av_strncasecmp(const char * a,const char * b,size_t n)229 int av_strncasecmp(const char *a, const char *b, size_t n)
230 {
231     uint8_t c1, c2;
232     if (n <= 0)
233         return 0;
234     do {
235         c1 = av_tolower(*a++);
236         c2 = av_tolower(*b++);
237     } while (--n && c1 && c1 == c2);
238     return c1 - c2;
239 }
240 
av_strireplace(const char * str,const char * from,const char * to)241 char *av_strireplace(const char *str, const char *from, const char *to)
242 {
243     char *ret = NULL;
244     const char *pstr2, *pstr = str;
245     size_t tolen = strlen(to), fromlen = strlen(from);
246     AVBPrint pbuf;
247 
248     av_bprint_init(&pbuf, 1, AV_BPRINT_SIZE_UNLIMITED);
249     while ((pstr2 = av_stristr(pstr, from))) {
250         av_bprint_append_data(&pbuf, pstr, pstr2 - pstr);
251         pstr = pstr2 + fromlen;
252         av_bprint_append_data(&pbuf, to, tolen);
253     }
254     av_bprint_append_data(&pbuf, pstr, strlen(pstr));
255     if (!av_bprint_is_complete(&pbuf)) {
256         av_bprint_finalize(&pbuf, NULL);
257     } else {
258         av_bprint_finalize(&pbuf, &ret);
259     }
260 
261     return ret;
262 }
263 
av_basename(const char * path)264 const char *av_basename(const char *path)
265 {
266     char *p;
267 #if HAVE_DOS_PATHS
268     char *q, *d;
269 #endif
270 
271     if (!path || *path == '\0')
272         return ".";
273 
274     p = strrchr(path, '/');
275 #if HAVE_DOS_PATHS
276     q = strrchr(path, '\\');
277     d = strchr(path, ':');
278     p = FFMAX3(p, q, d);
279 #endif
280 
281     if (!p)
282         return path;
283 
284     return p + 1;
285 }
286 
av_dirname(char * path)287 const char *av_dirname(char *path)
288 {
289     char *p = path ? strrchr(path, '/') : NULL;
290 
291 #if HAVE_DOS_PATHS
292     char *q = path ? strrchr(path, '\\') : NULL;
293     char *d = path ? strchr(path, ':')  : NULL;
294 
295     d = d ? d + 1 : d;
296 
297     p = FFMAX3(p, q, d);
298 #endif
299 
300     if (!p)
301         return ".";
302 
303     *p = '\0';
304 
305     return path;
306 }
307 
av_append_path_component(const char * path,const char * component)308 char *av_append_path_component(const char *path, const char *component)
309 {
310     size_t p_len, c_len;
311     char *fullpath;
312 
313     if (!path)
314         return av_strdup(component);
315     if (!component)
316         return av_strdup(path);
317 
318     p_len = strlen(path);
319     c_len = strlen(component);
320     if (p_len > SIZE_MAX - c_len || p_len + c_len > SIZE_MAX - 2)
321         return NULL;
322     fullpath = av_malloc(p_len + c_len + 2);
323     if (fullpath) {
324         if (p_len) {
325             av_strlcpy(fullpath, path, p_len + 1);
326             if (c_len) {
327                 if (fullpath[p_len - 1] != '/' && component[0] != '/')
328                     fullpath[p_len++] = '/';
329                 else if (fullpath[p_len - 1] == '/' && component[0] == '/')
330                     p_len--;
331             }
332         }
333         av_strlcpy(&fullpath[p_len], component, c_len + 1);
334         fullpath[p_len + c_len] = 0;
335     }
336     return fullpath;
337 }
338 
av_escape(char ** dst,const char * src,const char * special_chars,enum AVEscapeMode mode,int flags)339 int av_escape(char **dst, const char *src, const char *special_chars,
340               enum AVEscapeMode mode, int flags)
341 {
342     AVBPrint dstbuf;
343     int ret;
344 
345     av_bprint_init(&dstbuf, 1, INT_MAX); /* (int)dstbuf.len must be >= 0 */
346     av_bprint_escape(&dstbuf, src, special_chars, mode, flags);
347 
348     if (!av_bprint_is_complete(&dstbuf)) {
349         av_bprint_finalize(&dstbuf, NULL);
350         return AVERROR(ENOMEM);
351     }
352     if ((ret = av_bprint_finalize(&dstbuf, dst)) < 0)
353         return ret;
354     return dstbuf.len;
355 }
356 
av_match_name(const char * name,const char * names)357 int av_match_name(const char *name, const char *names)
358 {
359     const char *p;
360     int len, namelen;
361 
362     if (!name || !names)
363         return 0;
364 
365     namelen = strlen(name);
366     while (*names) {
367         int negate = '-' == *names;
368         p = strchr(names, ',');
369         if (!p)
370             p = names + strlen(names);
371         names += negate;
372         len = FFMAX(p - names, namelen);
373         if (!av_strncasecmp(name, names, len) || !strncmp("ALL", names, FFMAX(3, p - names)))
374             return !negate;
375         names = p + (*p == ',');
376     }
377     return 0;
378 }
379 
av_utf8_decode(int32_t * codep,const uint8_t ** bufp,const uint8_t * buf_end,unsigned int flags)380 int av_utf8_decode(int32_t *codep, const uint8_t **bufp, const uint8_t *buf_end,
381                    unsigned int flags)
382 {
383     const uint8_t *p = *bufp;
384     uint32_t top;
385     uint64_t code;
386     int ret = 0, tail_len;
387     uint32_t overlong_encoding_mins[6] = {
388         0x00000000, 0x00000080, 0x00000800, 0x00010000, 0x00200000, 0x04000000,
389     };
390 
391     if (p >= buf_end)
392         return 0;
393 
394     code = *p++;
395 
396     /* first sequence byte starts with 10, or is 1111-1110 or 1111-1111,
397        which is not admitted */
398     if ((code & 0xc0) == 0x80 || code >= 0xFE) {
399         ret = AVERROR(EILSEQ);
400         goto end;
401     }
402     top = (code & 128) >> 1;
403 
404     tail_len = 0;
405     while (code & top) {
406         int tmp;
407         tail_len++;
408         if (p >= buf_end) {
409             (*bufp) ++;
410             return AVERROR(EILSEQ); /* incomplete sequence */
411         }
412 
413         /* we assume the byte to be in the form 10xx-xxxx */
414         tmp = *p++ - 128;   /* strip leading 1 */
415         if (tmp>>6) {
416             (*bufp) ++;
417             return AVERROR(EILSEQ);
418         }
419         code = (code<<6) + tmp;
420         top <<= 5;
421     }
422     code &= (top << 1) - 1;
423 
424     /* check for overlong encodings */
425     av_assert0(tail_len <= 5);
426     if (code < overlong_encoding_mins[tail_len]) {
427         ret = AVERROR(EILSEQ);
428         goto end;
429     }
430 
431     if (code >= 1U<<31) {
432         ret = AVERROR(EILSEQ);  /* out-of-range value */
433         goto end;
434     }
435 
436     *codep = code;
437 
438     if (code > 0x10FFFF &&
439         !(flags & AV_UTF8_FLAG_ACCEPT_INVALID_BIG_CODES))
440         ret = AVERROR(EILSEQ);
441     if (code < 0x20 && code != 0x9 && code != 0xA && code != 0xD &&
442         flags & AV_UTF8_FLAG_EXCLUDE_XML_INVALID_CONTROL_CODES)
443         ret = AVERROR(EILSEQ);
444     if (code >= 0xD800 && code <= 0xDFFF &&
445         !(flags & AV_UTF8_FLAG_ACCEPT_SURROGATES))
446         ret = AVERROR(EILSEQ);
447     if ((code == 0xFFFE || code == 0xFFFF) &&
448         !(flags & AV_UTF8_FLAG_ACCEPT_NON_CHARACTERS))
449         ret = AVERROR(EILSEQ);
450 
451 end:
452     *bufp = p;
453     return ret;
454 }
455 
av_match_list(const char * name,const char * list,char separator)456 int av_match_list(const char *name, const char *list, char separator)
457 {
458     const char *p, *q;
459 
460     for (p = name; p && *p; ) {
461         for (q = list; q && *q; ) {
462             int k;
463             for (k = 0; p[k] == q[k] || (p[k]*q[k] == 0 && p[k]+q[k] == separator); k++)
464                 if (k && (!p[k] || p[k] == separator))
465                     return 1;
466             q = strchr(q, separator);
467             q += !!q;
468         }
469         p = strchr(p, separator);
470         p += !!p;
471     }
472 
473     return 0;
474 }
475