ShellPkg/Include/Library/FileHandleLib.h

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