docs/reference/glib/tmpl/fileutils.sgml

   1 <!-- ##### SECTION Title ##### -->
   2 File Utilities
   3
   4 <!-- ##### SECTION Short_Description ##### -->
   5 various file-related functions.
   6
   7 <!-- ##### SECTION Long_Description ##### -->
   8 <para>
   9 There is a group of functions which wrap the common POSIX functions
  10 dealing with filenames (g_open(), g_rename(), g_mkdir(), g_stat(),
  11 g_unlink(), g_remove(), g_fopen(), g_freopen()). The point of these
  12 wrappers is to make it possible to handle file names with any Unicode
  13 characters in them on Windows without having to use ifdefs and the
  14 wide character API in the application code.
  15 </para>
  16 <para>
  17 The pathname argument should be in the GLib file name encoding. On
  18 POSIX this is the actual on-disk encoding which might correspond to
  19 the locale settings of the process (or the
  20 <envar>G_FILENAME_ENCODING</envar> environment variable), or not.
  21 </para>
  22 <para>
  23 On Windows the GLib file name encoding is UTF-8. Note that the
  24 Microsoft C library does not use UTF-8, but has separate APIs for
  25 current system code page and wide characters (UTF-16). The GLib
  26 wrappers call the wide character API if present (on modern Windows
  27 systems), otherwise convert to/from the system code page.
  28 </para>
  29
  30 <para>
  31 Another group of functions allows to open and read directories
  32 in the GLib file name encoding. These are g_dir_open(),
  33 g_dir_read_name(), g_dir_rewind(), g_dir_close().
  34 </para>
  35
  36 <!-- ##### SECTION See_Also ##### -->
  37 <para>
  38
  39 </para>
  40
  41 <!-- ##### ENUM GFileError ##### -->
  42 <para>
  43 Values corresponding to <literal>errno</literal> codes returned from file operations
  44 on UNIX. Unlike <literal>errno</literal> codes, #GFileError values are available on
  45 all systems, even Windows. The exact meaning of each code depends on what
  46 sort of file operation you were performing; the UNIX documentation
  47 gives more details. The following error code descriptions come
  48 from the GNU C Library manual, and are under the copyright
  49 of that manual.
  50 </para>
  51
  52 <para>
  53 It's not very portable to make detailed assumptions about exactly
  54 which errors will be returned from a given operation. Some errors
  55 don't occur on some systems, etc., sometimes there are subtle
  56 differences in when a system will report a given error, etc.
  57 </para>
  58
  59 @G_FILE_ERROR_EXIST: Operation not permitted; only the owner of the
  60      file (or other resource) or processes with special privileges can
  61      perform the operation.
  62 @G_FILE_ERROR_ISDIR: File is a directory; you cannot open a directory
  63      for writing, or create or remove hard links to it.
  64 @G_FILE_ERROR_ACCES: Permission denied; the file permissions do not
  65      allow the attempted operation.
  66 @G_FILE_ERROR_NAMETOOLONG: Filename too long.
  67 @G_FILE_ERROR_NOENT: No such file or directory.  This is a "file
  68      doesn't exist" error for ordinary files that are referenced in
  69      contexts where they are expected to already exist.
  70 @G_FILE_ERROR_NOTDIR: A file that isn't a directory was specified when
  71      a directory is required.
  72 @G_FILE_ERROR_NXIO: No such device or address.  The system tried to
  73      use the device represented by a file you specified, and it
  74      couldn't find the device.  This can mean that the device file was
  75      installed incorrectly, or that the physical device is missing or
  76      not correctly attached to the computer.
  77 @G_FILE_ERROR_NODEV: This file is of a type that doesn't support
  78      mapping.
  79 @G_FILE_ERROR_ROFS: The directory containing the new link can't be
  80           modified because it's on a read-only file system.
  81 @G_FILE_ERROR_TXTBSY: Text file busy.
  82 @G_FILE_ERROR_FAULT: You passed in a pointer to bad memory.
  83   (GLib won't reliably return this, don't pass in pointers to bad
  84   memory.)
  85 @G_FILE_ERROR_LOOP: Too many levels of symbolic links were encountered
  86   in looking up a file name.  This often indicates a cycle of symbolic
  87   links.
  88 @G_FILE_ERROR_NOSPC: No space left on device; write operation on a
  89   file failed because the disk is full.
  90 @G_FILE_ERROR_NOMEM: No memory available.  The system cannot allocate
  91      more virtual memory because its capacity is full.
  92 @G_FILE_ERROR_MFILE: The current process has too many files open and
  93      can't open any more.  Duplicate descriptors do count toward this
  94      limit.
  95 @G_FILE_ERROR_NFILE: There are too many distinct file openings in the
  96      entire system.
  97 @G_FILE_ERROR_BADF: Bad file descriptor; for example, I/O on a
  98      descriptor that has been closed or reading from a descriptor open
  99      only for writing (or vice versa).
 100 @G_FILE_ERROR_INVAL: Invalid argument.  This is used to indicate
 101      various kinds of problems with passing the wrong argument to a
 102      library function.
 103 @G_FILE_ERROR_PIPE: Broken pipe; there is no process reading from the
 104      other end of a pipe.  Every library function that returns this
 105      error code also generates a `SIGPIPE' signal; this signal
 106      terminates the program if not handled or blocked.  Thus, your
 107      program will never actually see this code unless it has handled or
 108      blocked `SIGPIPE'.
 109 @G_FILE_ERROR_AGAIN: Resource temporarily unavailable; the call might
 110      work if you try again later.
 111 @G_FILE_ERROR_INTR: Interrupted function call; an asynchronous signal
 112      occurred and prevented completion of the call.  When this
 113      happens, you should try the call again.
 114 @G_FILE_ERROR_IO: Input/output error; usually used for physical read
 115     or write errors. i.e. the disk or other physical device hardware
 116     is returning errors.
 117 @G_FILE_ERROR_PERM: Operation not permitted; only the owner of the
 118      file (or other resource) or processes with special privileges can
 119      perform the operation.
 120 @G_FILE_ERROR_NOSYS: Function not implemented; this indicates that the
 121     system is missing some functionality.
 122 @G_FILE_ERROR_FAILED: Does not correspond to a UNIX error code; this
 123   is the standard "failed for unspecified reason" error code present in
 124   all #GError error code enumerations. Returned if no specific
 125   code applies.
 126
 127 <!-- ##### MACRO G_FILE_ERROR ##### -->
 128 <para>
 129 Error domain for file operations. Errors in this domain will
 130 be from the #GFileError enumeration. See #GError for information on
 131 error domains.
 132 </para>
 133
 134
 135
 136 <!-- ##### ENUM GFileTest ##### -->
 137 <para>
 138 A test to perform on a file using g_file_test().
 139 </para>
 140
 141 @G_FILE_TEST_IS_REGULAR: %TRUE if the file is a regular file (not a symlink or directory)
 142 @G_FILE_TEST_IS_SYMLINK: %TRUE if the file is a symlink.
 143 @G_FILE_TEST_IS_DIR: %TRUE if the file is a directory.
 144 @G_FILE_TEST_IS_EXECUTABLE: %TRUE if the file is executable.
 145 @G_FILE_TEST_EXISTS: %TRUE if the file exists. It may or may not be a regular file.
 146
 147 <!-- ##### FUNCTION g_file_error_from_errno ##### -->
 148 <para>
 149
 150 </para>
 151
 152 @err_no:
 153 @Returns:
 154
 155
 156 <!-- ##### FUNCTION g_file_get_contents ##### -->
 157 <para>
 158
 159 </para>
 160
 161 @filename:
 162 @contents:
 163 @length:
 164 @error:
 165 @Returns:
 166
 167
 168 <!-- ##### FUNCTION g_file_test ##### -->
 169 <para>
 170
 171 </para>
 172
 173 @filename:
 174 @test:
 175 @Returns:
 176
 177
 178 <!-- ##### FUNCTION g_mkstemp ##### -->
 179 <para>
 180
 181 </para>
 182
 183 @tmpl:
 184 @Returns:
 185
 186
 187 <!-- ##### FUNCTION g_file_open_tmp ##### -->
 188 <para>
 189
 190 </para>
 191
 192 @tmpl:
 193 @name_used:
 194 @error:
 195 @Returns:
 196
 197
 198 <!-- ##### FUNCTION g_file_read_link ##### -->
 199 <para>
 200
 201 </para>
 202
 203 @filename:
 204 @error:
 205 @Returns:
 206
 207
 208 <!-- ##### STRUCT GDir ##### -->
 209 <para>
 210 An opaque structure representing an opened directory.
 211 </para>
 212
 213
 214 <!-- ##### FUNCTION g_dir_open ##### -->
 215 <para>
 216
 217 </para>
 218
 219 @path:
 220 @flags:
 221 @error:
 222 @Returns:
 223
 224
 225 <!-- ##### FUNCTION g_dir_read_name ##### -->
 226 <para>
 227
 228 </para>
 229
 230 @dir:
 231 @Returns:
 232
 233
 234 <!-- ##### FUNCTION g_dir_rewind ##### -->
 235 <para>
 236
 237 </para>
 238
 239 @dir:
 240
 241
 242 <!-- ##### FUNCTION g_dir_close ##### -->
 243 <para>
 244
 245 </para>
 246
 247 @dir:
 248
 249
 250 <!-- ##### FUNCTION g_open ##### -->
 251 <para>
 252
 253 </para>
 254
 255 @filename:
 256 @flags:
 257 @mode:
 258 @Returns:
 259
 260
 261 <!-- ##### FUNCTION g_rename ##### -->
 262 <para>
 263
 264 </para>
 265
 266 @oldfilename:
 267 @newfilename:
 268 @Returns:
 269
 270
 271 <!-- ##### FUNCTION g_mkdir ##### -->
 272 <para>
 273
 274 </para>
 275
 276 @filename:
 277 @mode:
 278 @Returns:
 279
 280
 281 <!-- ##### FUNCTION g_stat ##### -->
 282 <para>
 283
 284 </para>
 285
 286 @filename:
 287 @buf:
 288 @Returns:
 289
 290
 291 <!-- ##### FUNCTION g_unlink ##### -->
 292 <para>
 293
 294 </para>
 295
 296 @filename:
 297 @Returns:
 298
 299
 300 <!-- ##### FUNCTION g_remove ##### -->
 301 <para>
 302
 303 </para>
 304
 305 @filename:
 306 @Returns:
 307
 308
 309 <!-- ##### FUNCTION g_fopen ##### -->
 310 <para>
 311
 312 </para>
 313
 314 @filename:
 315 @mode:
 316 @Returns:
 317
 318
 319 <!-- ##### FUNCTION g_freopen ##### -->
 320 <para>
 321
 322 </para>
 323
 324 @filename:
 325 @mode:
 326 @stream:
 327 @Returns:
 328
 329