ShellPkg/Include/Library/FileHandleLib.h

   1 /** @file
   2   Provides interface to EFI_FILE_HANDLE functionality.
   3
   4   Copyright (c) 2009 - 2010, Intel Corporation. All rights reserved.<BR>
   5   This program and the accompanying materials
   6   are licensed and made available under the terms and conditions of the BSD License
   7   which accompanies this distribution.  The full text of the license may be found at
   8   http://opensource.org/licenses/bsd-license.php
   9
  10   THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,
  11   WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
  12
  13 **/
  14
  15 #ifndef _FILE_HANDLE_LIBRARY_HEADER_
  16 #define _FILE_HANDLE_LIBRARY_HEADER_
  17
  18 #include <Protocol/SimpleFileSystem.h>
  19
  20 /// The tag for use in identifying UNICODE files.
  21 /// If the file is UNICODE, the first 16 bits of the file will equal this value.
  22 enum {
  23   UnicodeFileTag = 0xFEFF
  24 };
  25
  26 /**
  27   This function retrieves information about the file for the handle
  28   specified and stores it in the allocated pool memory.
  29
  30   This function allocates a buffer to store the file's information. It is the
  31   caller's responsibility to free the buffer.
  32
  33   @param[in] FileHandle         The file handle of the file for which information is
  34                                 being requested.
  35
  36   @retval NULL                  Information could not be retrieved.
  37   @retval !NULL                 The information about the file.
  38 **/
  39 EFI_FILE_INFO*
  40 EFIAPI
  41 FileHandleGetInfo (
  42   IN EFI_FILE_HANDLE            FileHandle
  43   );
  44
  45 /**
  46   This function sets the information about the file for the opened handle
  47   specified.
  48
  49   @param[in]  FileHandle        The file handle of the file for which information
  50                                 is being set.
  51
  52   @param[in]  FileInfo          The information to set.
  53
  54   @retval EFI_SUCCESS                   The information was set.
  55   @retval EFI_INVALID_PARAMETER A parameter was out of range or invalid.
  56   @retval EFI_UNSUPPORTED       The FileHandle does not support FileInfo.
  57   @retval EFI_NO_MEDIA                The device has no medium.
  58   @retval EFI_DEVICE_ERROR          The device reported an error.
  59   @retval EFI_VOLUME_CORRUPTED  The file system structures are corrupted.
  60   @retval EFI_WRITE_PROTECTED     The file or medium is write protected.
  61   @retval EFI_ACCESS_DENIED     The file was opened read only.
  62   @retval EFI_VOLUME_FULL       The volume is full.
  63 **/
  64 EFI_STATUS
  65 EFIAPI
  66 FileHandleSetInfo (
  67   IN EFI_FILE_HANDLE            FileHandle,
  68   IN CONST EFI_FILE_INFO        *FileInfo
  69   );
  70
  71 /**
  72   This function reads information from an opened file.
  73
  74   If FileHandle is not a directory, the function reads the requested number of
  75   bytes from the file at the file's current position and returns them in Buffer.
  76   If the read goes beyond the end of the file, the read length is truncated to the
  77   end of the file. The file's current position is increased by the number of bytes
  78   returned.  If FileHandle is a directory, the function reads the directory entry
  79   at the file's current position and returns the entry in Buffer. If the Buffer
  80   is not large enough to hold the current directory entry, then
  81   EFI_BUFFER_TOO_SMALL is returned and the current file position is not updated.
  82   BufferSize is set to be the size of the buffer needed to read the entry. On
  83   success, the current position is updated to the next directory entry. If there
  84   are no more directory entries, the read returns a zero-length buffer.
  85   EFI_FILE_INFO is the structure returned as the directory entry.
  86
  87   @param[in] FileHandle         The opened file handle.
  88   @param[in,out] BufferSize     On input, the size of buffer in bytes.  On return,
  89                                 the number of bytes written.
  90   @param[out] Buffer            The buffer to put read data into.
  91
  92   @retval EFI_SUCCESS           Data was read.
  93   @retval EFI_NO_MEDIA          The device has no media.
  94   @retval EFI_DEVICE_ERROR      The device reported an error.
  95   @retval EFI_VOLUME_CORRUPTED  The file system structures are corrupted.
  96   @retval EFI_BUFFER_TO_SMALL   Buffer is too small. ReadSize contains required
  97                                 size.
  98
  99 **/
 100 EFI_STATUS
 101 EFIAPI
 102 FileHandleRead(
 103   IN EFI_FILE_HANDLE            FileHandle,
 104   IN OUT UINTN                  *BufferSize,
 105   OUT VOID                      *Buffer
 106   );
 107
 108 /**
 109   Write data to a file.
 110
 111   This function writes the specified number of bytes to the file at the current
 112   file position. The current file position is advanced the actual number of bytes
 113   written, which is returned in BufferSize. Partial writes only occur when there
 114   has been a data error during the write attempt (such as "volume space full").
 115   The file is automatically grown to hold the data if required. Direct writes to
 116   opened directories are not supported.
 117
 118   @param[in] FileHandle         The opened file for writing.
 119   @param[in,out] BufferSize     On input, the number of bytes in Buffer.  On output,
 120                                 the number of bytes written.
 121   @param[in] Buffer             The buffer containing data to write is stored.
 122
 123   @retval EFI_SUCCESS           Data was written.
 124   @retval EFI_UNSUPPORTED       Writes to an open directory are not supported.
 125   @retval EFI_NO_MEDIA          The device has no media.
 126   @retval EFI_DEVICE_ERROR      The device reported an error.
 127   @retval EFI_VOLUME_CORRUPTED  The file system structures are corrupted.
 128   @retval EFI_WRITE_PROTECTED   The device is write-protected.
 129   @retval EFI_ACCESS_DENIED     The file was opened for read only.
 130   @retval EFI_VOLUME_FULL       The volume is full.
 131 **/
 132 EFI_STATUS
 133 EFIAPI
 134 FileHandleWrite(
 135   IN EFI_FILE_HANDLE            FileHandle,
 136   IN OUT UINTN                  *BufferSize,
 137   IN VOID                       *Buffer
 138   );
 139
 140 /**
 141   Close an open file handle.
 142
 143   This function closes a specified file handle. All "dirty" cached file data is
 144   flushed to the device, and the file is closed. In all cases the handle is
 145   closed.
 146
 147   @param[in] FileHandle           The file handle to close.
 148
 149   @retval EFI_SUCCESS             The file handle was closed successfully.
 150 **/
 151 EFI_STATUS
 152 EFIAPI
 153 FileHandleClose (
 154   IN EFI_FILE_HANDLE            FileHandle
 155   );
 156
 157 /**
 158   Delete a file and close the handle.
 159
 160   This function closes and deletes a file. In all cases the file handle is closed.
 161   If the file cannot be deleted, the warning code EFI_WARN_DELETE_FAILURE is
 162   returned, but the handle is still closed.
 163
 164   @param[in] FileHandle             The file handle to delete.
 165
 166   @retval EFI_SUCCESS               The file was closed successfully.
 167   @retval EFI_WARN_DELETE_FAILURE   The handle was closed, but the file was not
 168                                     deleted.
 169   @retval INVALID_PARAMETER         One of the parameters has an invalid value.
 170 **/
 171 EFI_STATUS
 172 EFIAPI
 173 FileHandleDelete (
 174   IN EFI_FILE_HANDLE            FileHandle
 175   );
 176
 177 /**
 178   Set the current position in a file.
 179
 180   This function sets the current file position for the handle to the position
 181   supplied. With the exception of moving to position 0xFFFFFFFFFFFFFFFF, only
 182   absolute positioning is supported, and moving past the end of the file is
 183   allowed (a subsequent write would grow the file). Moving to position
 184   0xFFFFFFFFFFFFFFFF causes the current position to be set to the end of the file.
 185   If FileHandle is a directory, the only position that may be set is zero. This
 186   has the effect of starting the read process of the directory entries over again.
 187
 188   @param[in] FileHandle         The file handle on which the position is being set.
 189   @param[in] Position           The byte position from the begining of the file.
 190
 191   @retval EFI_SUCCESS           The operation completed sucessfully.
 192   @retval EFI_UNSUPPORTED       The request for non-zero is not valid on
 193                                 directories.
 194   @retval INVALID_PARAMETER     One of the parameters has an invalid value.
 195 **/
 196 EFI_STATUS
 197 EFIAPI
 198 FileHandleSetPosition (
 199   IN EFI_FILE_HANDLE    FileHandle,
 200   IN UINT64             Position
 201   );
 202
 203 /**
 204   Gets a file's current position.
 205
 206   This function retrieves the current file position for the file handle. For
 207   directories, the current file position has no meaning outside of the file
 208   system driver. As such, the operation is not supported. An error is returned
 209   if FileHandle is a directory.
 210
 211   @param[in] FileHandle         The open file handle on which to get the position.
 212   @param[out] Position          The byte position from begining of file.
 213
 214   @retval EFI_SUCCESS           The operation completed successfully.
 215   @retval INVALID_PARAMETER     One of the parameters has an invalid value.
 216   @retval EFI_UNSUPPORTED       The request is not valid on directories.
 217 **/
 218 EFI_STATUS
 219 EFIAPI
 220 FileHandleGetPosition (
 221   IN EFI_FILE_HANDLE            FileHandle,
 222   OUT UINT64                    *Position
 223   );
 224 /**
 225   Flushes data on a file.
 226
 227   This function flushes all modified data associated with a file to a device.
 228
 229   @param[in] FileHandle         The file handle on which to flush data.
 230
 231   @retval EFI_SUCCESS           The data was flushed.
 232   @retval EFI_NO_MEDIA          The device has no media.
 233   @retval EFI_DEVICE_ERROR      The device reported an error.
 234   @retval EFI_VOLUME_CORRUPTED  The file system structures are corrupted.
 235   @retval EFI_WRITE_PROTECTED   The file or medium is write protected.
 236   @retval EFI_ACCESS_DENIED     The file was opened for read only.
 237 **/
 238 EFI_STATUS
 239 EFIAPI
 240 FileHandleFlush (
 241   IN EFI_FILE_HANDLE            FileHandle
 242   );
 243
 244 /**
 245   Function to determine if a given handle is a directory handle.
 246
 247   If DirHandle is NULL, then ASSERT().
 248
 249   Open the file information on the DirHandle, and verify that the Attribute
 250   includes EFI_FILE_DIRECTORY bit set.
 251
 252   @param[in] DirHandle          The handle to open the file.
 253
 254   @retval EFI_SUCCESS           DirHandle is a directory.
 255   @retval EFI_INVALID_PARAMETER DirHandle did not have EFI_FILE_INFO available.
 256   @retval EFI_NOT_FOUND         DirHandle is not a directory.
 257 **/
 258 EFI_STATUS
 259 EFIAPI
 260 FileHandleIsDirectory (
 261   IN EFI_FILE_HANDLE            DirHandle
 262   );
 263
 264 /**
 265   Retrieves the first file from a directory.
 266
 267   This function opens a directory and gets the first file's information in the
 268   directory. The caller the uses FileHandleFindNextFile() to get other files.  When
 269   complete, the caller is responsible for calling FreePool() on *Buffer.
 270
 271   @param[in] DirHandle          The file handle of the directory to search.
 272   @param[out] Buffer            The pointer to pointer to buffer for file's information.
 273
 274   @retval EFI_SUCCESS           Found the first file.
 275   @retval EFI_NOT_FOUND         Cannot find the directory.
 276   @retval EFI_NO_MEDIA          The device has no media.
 277   @retval EFI_DEVICE_ERROR      The device reported an error.
 278   @retval EFI_VOLUME_CORRUPTED  The file system structures are corrupted.
 279   @return Others                The status of FileHandleGetInfo, FileHandleSetPosition,
 280                                 or FileHandleRead.
 281 **/
 282 EFI_STATUS
 283 EFIAPI
 284 FileHandleFindFirstFile (
 285   IN EFI_FILE_HANDLE            DirHandle,
 286   OUT EFI_FILE_INFO             **Buffer
 287   );
 288 /**
 289   Retrieves the next file in a directory.
 290
 291   To use this function, caller must call the FileHandleFindFirstFile() to get the
 292   first file, and then use this function get other files. This function can be
 293   called for several times to get each file's information in the directory. If
 294   the call of FileHandleFindNextFile() got the last file in the directory, the next
 295   call of this function has no file to get. *NoFile will be set to TRUE and the
 296   Buffer memory will be automatically freed.
 297
 298   @param[in] DirHandle          The file handle of the directory.
 299   @param[out] Buffer            The pointer to buffer for file's information.
 300   @param[out] NoFile            The pointer to boolean when last file is found.
 301
 302   @retval EFI_SUCCESS           Found the next file, or reached last file.
 303   @retval EFI_NO_MEDIA          The device has no media.
 304   @retval EFI_DEVICE_ERROR      The device reported an error.
 305   @retval EFI_VOLUME_CORRUPTED  The file system structures are corrupted.
 306 **/
 307 EFI_STATUS
 308 EFIAPI
 309 FileHandleFindNextFile(
 310   IN EFI_FILE_HANDLE             DirHandle,
 311   OUT EFI_FILE_INFO              *Buffer,
 312   OUT BOOLEAN                    *NoFile
 313   );
 314
 315 /**
 316   Retrieve the size of a file.
 317
 318   If FileHandle is NULL then ASSERT().
 319   If Size is NULL then ASSERT().
 320
 321   This function extracts the file size info from the FileHandle's EFI_FILE_INFO
 322   data.
 323
 324   @param[in] FileHandle         The file handle from which size is retrieved.
 325   @param[out] Size              The pointer to size.
 326
 327   @retval EFI_SUCCESS           The operation completed successfully.
 328   @retval EFI_DEVICE_ERROR      Cannot access the file.
 329 **/
 330 EFI_STATUS
 331 EFIAPI
 332 FileHandleGetSize (
 333   IN EFI_FILE_HANDLE            FileHandle,
 334   OUT UINT64                    *Size
 335   );
 336
 337 /**
 338   Set the size of a file.
 339
 340   If FileHandle is NULL then ASSERT().
 341
 342   This function changes the file size info from the FileHandle's EFI_FILE_INFO
 343   data.
 344
 345   @param[in] FileHandle         The file handle whose size is to be changed.
 346   @param[in] Size               The new size.
 347
 348   @retval EFI_SUCCESS           The operation completed successfully.
 349   @retval EFI_DEVICE_ERROR      Cannot access the file.
 350 **/
 351 EFI_STATUS
 352 EFIAPI
 353 FileHandleSetSize (
 354   IN EFI_FILE_HANDLE            FileHandle,
 355   IN UINT64                     Size
 356   );
 357
 358 /**
 359   Function to get a full filename given a EFI_FILE_HANDLE somewhere lower on the
 360   directory 'stack'.
 361
 362   @param[in] Handle             Handle to the Directory or File to create path to.
 363   @param[out] FullFileName      Pointer to pointer to generated full file name.  It
 364                                 is the responsibility of the caller to free this memory
 365                                 with a call to FreePool().
 366   @retval EFI_SUCCESS           The operation was successful and FullFileName is valid.
 367   @retval EFI_INVALID_PARAMETER Handle was NULL.
 368   @retval EFI_INVALID_PARAMETER FullFileName was NULL.
 369   @retval EFI_OUT_OF_MEMORY     A memory allocation failed.
 370 **/
 371 EFI_STATUS
 372 EFIAPI
 373 FileHandleGetFileName (
 374   IN CONST EFI_FILE_HANDLE      Handle,
 375   OUT CHAR16                    **FullFileName
 376   );
 377
 378 /**
 379   Function to read a single line (up to but not including the \n) from a file.
 380
 381   If the position upon start is 0, then the Ascii Boolean will be set.  This should be
 382   maintained and not changed for all operations with the same file.
 383
 384   @param[in]      Handle        FileHandle to read from.
 385   @param[in,out]  Buffer        The pointer to buffer to read into.
 386   @param[in,out]  Size          The pointer to number of bytes in Buffer.
 387   @param[in]      Truncate      If the buffer is large enough, this has no effect.
 388                                 If the buffer is is too small and Truncate is TRUE,
 389                                 the line will be truncated.
 390                                 If the buffer is is too small and Truncate is FALSE,
 391                                 then no read will occur.
 392
 393   @param[in,out]  Ascii         Boolean value for indicating whether the file is
 394                                 Ascii (TRUE) or UCS2 (FALSE).
 395
 396   @retval EFI_SUCCESS           The operation was successful.  The line is stored in
 397                                 Buffer.
 398   @retval EFI_INVALID_PARAMETER Handle was NULL.
 399   @retval EFI_INVALID_PARAMETER Size was NULL.
 400   @retval EFI_BUFFER_TOO_SMALL  Size was not large enough to store the line.
 401                                 Size was updated to the minimum space required.
 402   @sa FileHandleRead
 403 **/
 404 EFI_STATUS
 405 EFIAPI
 406 FileHandleReadLine(
 407   IN EFI_FILE_HANDLE            Handle,
 408   IN OUT CHAR16                 *Buffer,
 409   IN OUT UINTN                  *Size,
 410   IN BOOLEAN                    Truncate,
 411   IN OUT BOOLEAN                *Ascii
 412   );
 413
 414 /**
 415   Function to read a single line from a file. The \n is not included in the returned
 416   buffer.  The returned buffer must be callee freed.
 417
 418   If the position upon start is 0, then the Ascii Boolean will be set.  This should be
 419   maintained and not changed for all operations with the same file.
 420
 421   @param[in]      Handle        FileHandle to read from.
 422   @param[in,out]  Ascii         Boolean value for indicating whether the file is
 423                                 Ascii (TRUE) or UCS2 (FALSE).
 424
 425   @return                       The line of text from the file.
 426
 427   @sa FileHandleReadLine
 428 **/
 429 CHAR16*
 430 EFIAPI
 431 FileHandleReturnLine(
 432   IN EFI_FILE_HANDLE            Handle,
 433   IN OUT BOOLEAN                *Ascii
 434   );
 435
 436 /**
 437   Function to write a line of unicode text to a file.
 438
 439   If Handle is NULL, ASSERT.
 440
 441   @param[in]     Handle         FileHandle to write to.
 442   @param[in]     Buffer         Buffer to write, if NULL the function will
 443                                 take no action and return EFI_SUCCESS.
 444
 445   @retval  EFI_SUCCESS          The data was written.
 446   @retval  other                Failure.
 447
 448   @sa FileHandleWrite
 449 **/
 450 EFI_STATUS
 451 EFIAPI
 452 FileHandleWriteLine(
 453   IN EFI_FILE_HANDLE Handle,
 454   IN CHAR16          *Buffer
 455   );
 456
 457 /**
 458   Function to take a formatted argument and print it to a file.
 459
 460   @param[in] Handle   The file handle for the file to write to.
 461   @param[in] Format   The format argument (see printlib for the format specifier).
 462   @param[in] ...      The variable arguments for the format.
 463
 464   @retval EFI_SUCCESS The operation was successful.
 465   @retval other       A return value from FileHandleWriteLine.
 466
 467   @sa FileHandleWriteLine
 468 **/
 469 EFI_STATUS
 470 EFIAPI
 471 FileHandlePrintLine(
 472   IN EFI_FILE_HANDLE  Handle,
 473   IN CONST CHAR16     *Format,
 474   ...
 475   );
 476
 477 /**
 478   Function to determine if a FILE_HANDLE is at the end of the file.
 479
 480   This will NOT work on directories.
 481
 482   If Handle is NULL, then ASSERT().
 483
 484   @param[in] Handle     The file handle.
 485
 486   @retval TRUE          The position is at the end of the file.
 487   @retval FALSE         The position is not at the end of the file.
 488 **/
 489 BOOLEAN
 490 EFIAPI
 491 FileHandleEof(
 492   IN EFI_FILE_HANDLE Handle
 493   );
 494
 495 #endif //_FILE_HANDLE_LIBRARY_HEADER_
 496