FFmpeg: libavutil/file_open.c Source File

FFmpeg
file_open.c
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1 /*
2  * This file is part of FFmpeg.
3  *
4  * FFmpeg is free software; you can redistribute it and/or
5  * modify it under the terms of the GNU Lesser General Public
6  * License as published by the Free Software Foundation; either
7  * version 2.1 of the License, or (at your option) any later version.
8  *
9  * FFmpeg 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 GNU
12  * Lesser General Public License for more details.
13  *
14  * You should have received a copy of the GNU Lesser General Public
15  * License along with FFmpeg; if not, write to the Free Software
16  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
17  */
18 
19 #include "config.h"
20 #include "internal.h"
21 #include "mem.h"
22 #include <stdarg.h>
23 #include <fcntl.h>
24 #include <sys/stat.h>
25 #if HAVE_UNISTD_H
26 #include <unistd.h>
27 #endif
28 #if HAVE_IO_H
29 #include <io.h>
30 #endif
31 
32 #ifdef _WIN32
33 #undef open
34 #undef lseek
35 #undef stat
36 #undef fstat
37 #include <windows.h>
38 #include <share.h>
39 #include <errno.h>
40 #include "wchar_filename.h"
41 
42 static int win32_open(const char *filename_utf8, int oflag, int pmode)
43 {
44  int fd;
45  wchar_t *filename_w;
46 
47  /* convert UTF-8 to wide chars */
48  if (get_extended_win32_path(filename_utf8, &filename_w))
49  return -1;
50  if (!filename_w)
51  goto fallback;
52 
53  fd = _wsopen(filename_w, oflag, SH_DENYNO, pmode);
54  av_freep(&filename_w);
55 
56  if (fd != -1 || (oflag & O_CREAT))
57  return fd;
58 
59 fallback:
60  /* filename may be in CP_ACP */
61  return _sopen(filename_utf8, oflag, SH_DENYNO, pmode);
62 }
63 #define open win32_open
64 #endif
65 
66  int avpriv_open(const char *filename, int flags, ...)
67 {
68  int fd;
69  unsigned int mode = 0;
70  va_list ap;
71 
72  va_start(ap, flags);
73  if (flags & O_CREAT)
74  mode = va_arg(ap, unsigned int);
75  va_end(ap);
76 
77 #ifdef O_CLOEXEC
78  flags |= O_CLOEXEC;
79 #endif
80 #ifdef O_NOINHERIT
81  flags |= O_NOINHERIT;
82 #endif
83 
84  fd = open(filename, flags, mode);
85 #if HAVE_FCNTL
86  if (fd != -1) {
87  if (fcntl(fd, F_SETFD, FD_CLOEXEC) == -1)
88  av_log(NULL, AV_LOG_DEBUG, "Failed to set close on exec\n");
89  }
90 #endif
91 
92  return fd;
93 }
94 
95 typedef struct FileLogContext {
96  const AVClass *class;
97  int log_offset;
98  void *log_ctx;
99 } FileLogContext;
100 
101  static const AVClass file_log_ctx_class = {
102  .class_name = "TEMPFILE",
103  .item_name = av_default_item_name,
104  .option = NULL,
105  .version = LIBAVUTIL_VERSION_INT,
106  .log_level_offset_offset = offsetof(FileLogContext, log_offset),
107  .parent_log_context_offset = offsetof(FileLogContext, log_ctx),
108 };
109 
110  int avpriv_tempfile(const char *prefix, char **filename, int log_offset, void *log_ctx)
111 {
112  FileLogContext file_log_ctx = { &file_log_ctx_class, log_offset, log_ctx };
113  int fd = -1;
114 #if !HAVE_MKSTEMP
115  void *ptr= tempnam(NULL, prefix);
116  if(!ptr)
117  ptr= tempnam(".", prefix);
118  *filename = av_strdup(ptr);
119 #undef free
120  free(ptr);
121 #else
122  size_t len = strlen(prefix) + 12; /* room for "/tmp/" and "XXXXXX0円" */
123  *filename = av_malloc(len);
124 #endif
125  /* -----common section-----*/
126  if (!*filename) {
127  av_log(&file_log_ctx, AV_LOG_ERROR, "ff_tempfile: Cannot allocate file name\n");
128  return AVERROR(ENOMEM);
129  }
130 #if !HAVE_MKSTEMP
131 # ifndef O_BINARY
132 # define O_BINARY 0
133 # endif
134 # ifndef O_EXCL
135 # define O_EXCL 0
136 # endif
137  fd = open(*filename, O_RDWR | O_BINARY | O_CREAT | O_EXCL, 0600);
138 #else
139  snprintf(*filename, len, "/tmp/%sXXXXXX", prefix);
140  fd = mkstemp(*filename);
141 #if defined(_WIN32) || defined (__ANDROID__) || defined(__DJGPP__)
142  if (fd < 0) {
143  snprintf(*filename, len, "./%sXXXXXX", prefix);
144  fd = mkstemp(*filename);
145  }
146 #endif
147 #endif
148  /* -----common section-----*/
149  if (fd < 0) {
150  int err = AVERROR(errno);
151  av_log(&file_log_ctx, AV_LOG_ERROR, "ff_tempfile: Cannot open temporary file %s\n", *filename);
152  av_freep(filename);
153  return err;
154  }
155  return fd; /* success */
156 }
157 
158  FILE *avpriv_fopen_utf8(const char *path, const char *mode)
159 {
160  int fd;
161  int access;
162  const char *m = mode;
163 
164  switch (*m++) {
165  case 'r': access = O_RDONLY; break;
166  case 'w': access = O_CREAT|O_WRONLY|O_TRUNC; break;
167  case 'a': access = O_CREAT|O_WRONLY|O_APPEND; break;
168  default :
169  errno = EINVAL;
170  return NULL;
171  }
172  while (*m) {
173  if (*m == '+') {
174  access &= ~(O_RDONLY | O_WRONLY);
175  access |= O_RDWR;
176  } else if (*m == 'b') {
177 #ifdef O_BINARY
178  access |= O_BINARY;
179 #endif
180  } else if (*m) {
181  errno = EINVAL;
182  return NULL;
183  }
184  m++;
185  }
186  fd = avpriv_open(path, access, 0666);
187  if (fd == -1)
188  return NULL;
189  return fdopen(fd, mode);
190 }
191 
192 #if FF_API_AV_FOPEN_UTF8
193  FILE *av_fopen_utf8(const char *path, const char *mode)
194 {
195  return avpriv_fopen_utf8(path, mode);
196 }
197 #endif
wchar_filename.h
AVERROR
Filter the word "frame" indicates either a video frame or a group of audio as stored in an AVFrame structure Format for each input and each output the list of supported formats For video that means pixel format For audio that means channel sample they are references to shared objects When the negotiation mechanism computes the intersection of the formats supported at each end of a all references to both lists are replaced with a reference to the intersection And when a single format is eventually chosen for a link amongst the remaining all references to the list are updated That means that if a filter requires that its input and output have the same format amongst a supported all it has to do is use a reference to the same list of formats query_formats can leave some formats unset and return AVERROR(EAGAIN) to cause the negotiation mechanism toagain later. That can be used by filters with complex requirements to use the format negotiated on one link to set the formats supported on another. Frame references ownership and permissions
FileLogContext::log_offset
int log_offset
Definition: file.c:40
av_malloc
#define av_malloc(s)
Definition: tableprint_vlc.h:30
AV_LOG_ERROR
#define AV_LOG_ERROR
Something went wrong and cannot losslessly be recovered.
Definition: log.h:180
avpriv_open
int avpriv_open(const char *filename, int flags,...)
A wrapper for open() setting O_CLOEXEC.
Definition: file_open.c:66
AV_LOG_DEBUG
#define AV_LOG_DEBUG
Stuff which is only useful for libav* developers.
Definition: log.h:201
LIBAVUTIL_VERSION_INT
#define LIBAVUTIL_VERSION_INT
Definition: version.h:85
AVClass
Describe the class of an AVClass context structure.
Definition: log.h:66
NULL
#define NULL
Definition: coverity.c:32
O_EXCL
#define O_EXCL
av_default_item_name
const char * av_default_item_name(void *ptr)
Return the context name.
Definition: log.c:237
avpriv_tempfile
int avpriv_tempfile(const char *prefix, char **filename, int log_offset, void *log_ctx)
Wrapper to work around the lack of mkstemp() on mingw.
Definition: file_open.c:110
av_fopen_utf8
FILE * av_fopen_utf8(const char *path, const char *mode)
Open a file using a UTF-8 filename.
Definition: file_open.c:193
FileLogContext
Definition: file.c:38
file_log_ctx_class
static const AVClass file_log_ctx_class
Definition: file_open.c:101
internal.h
len
int len
Definition: vorbis_enc_data.h:426
avpriv_fopen_utf8
FILE * avpriv_fopen_utf8(const char *path, const char *mode)
Open a file using a UTF-8 filename.
Definition: file_open.c:158
O_BINARY
#define O_BINARY
AVClass::class_name
const char * class_name
The name of the class; usually it is the same name as the context structure type to which the AVClass...
Definition: log.h:71
FileLogContext::log_ctx
void * log_ctx
Definition: file.c:41
mode
mode
Definition: ebur128.h:83
av_strdup
char * av_strdup(const char *s)
Duplicate a string.
Definition: mem.c:280
mem.h
av_freep
#define av_freep(p)
Definition: tableprint_vlc.h:34
flags
#define flags(name, subs,...)
Definition: cbs_av1.c:561
av_log
#define av_log(a,...)
Definition: tableprint_vlc.h:27
snprintf
#define snprintf
Definition: snprintf.h:34
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