class RFile : public RSubSessionBase |
Creates and opens a file, and performs all operations on a single open file.
These include:
reading from and writing to the file
seeking to a position within the file
locking and unlocking within the file
setting file attributes
Before using any of these services, a connection to a file server session must have been made, and the file must be open.
Opening Files:
use Create() to create and open a new file for writing; an error is returned if it already exists.
use Replace() to open a file for writing, replacing any existing file of the same name if one exists, or creating a new file if one does not exist. Note that if a file exists, its length is reset to zero.
use Temp() to create and open a temporary file with a unique name, for writing and reading.
When opening a file, you must specify the file server session to use for operations with that file. If you do not close the file explicitly, it is closed when the server session associated with it is closed.
Reading and Writing:
There are several variants of both Read() and Write() . The basic Read(TDes8& aDes) and Write(const TDesC8& aDes) are supplemented by variants allowing the descriptor length to be overridden, or the seek position of the first byte to be specified, or asynchronous completion, or any combination.
Reading transfers data from a file to a descriptor, and writing transfers data from a descriptor to a file. In all cases, the file data is treated as binary and byte descriptors are used ( TDes8 , TDesC8 ).
Public Member Functions | |
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EFSRV_IMPORT_C TInt | Adopt ( RFs &, TInt ) |
EFSRV_IMPORT_C TInt | AdoptFromClient (const RMessage2 &, TInt , TInt ) |
EFSRV_IMPORT_C TInt | AdoptFromCreator ( TInt , TInt ) |
EFSRV_IMPORT_C TInt | AdoptFromServer ( TInt , TInt ) |
EFSRV_IMPORT_C TInt | Att ( TUint &) |
EFSRV_IMPORT_C TInt | BlockMap ( SBlockMapInfo &, TInt64 &, TInt64 , TInt ) |
EFSRV_IMPORT_C TInt | ChangeMode ( TFileMode ) |
TInt | Clamp ( RFileClamp &) |
EFSRV_IMPORT_C void | Close () |
EFSRV_IMPORT_C TInt | Create ( RFs &, const TDesC &, TUint ) |
EFSRV_IMPORT_C TInt | Drive ( TInt &, TDriveInfo &) |
EFSRV_IMPORT_C TInt | Duplicate (const RFile &, TOwnerType ) |
EFSRV_IMPORT_C TInt | Flush () |
EFSRV_IMPORT_C void | Flush ( TRequestStatus &) |
EFSRV_IMPORT_C TInt | FullName ( TDes &) |
EFSRV_IMPORT_C TInt | Lock ( TInt , TInt ) |
EFSRV_IMPORT_C TInt | Modified ( TTime &) |
EFSRV_IMPORT_C TInt | Name ( TDes &) |
EFSRV_IMPORT_C TInt | Open ( RFs &, const TDesC &, TUint ) |
EFSRV_IMPORT_C TInt | Read ( TDes8 &) |
EFSRV_IMPORT_C void | Read ( TDes8 &, TRequestStatus &) |
EFSRV_IMPORT_C TInt | Read ( TDes8 &, TInt ) |
EFSRV_IMPORT_C void | Read ( TDes8 &, TInt , TRequestStatus &) |
EFSRV_IMPORT_C TInt | Read ( TInt , TDes8 &) |
EFSRV_IMPORT_C void | Read ( TInt , TDes8 &, TRequestStatus &) |
EFSRV_IMPORT_C TInt | Read ( TInt , TDes8 &, TInt ) |
EFSRV_IMPORT_C void | Read ( TInt , TDes8 &, TInt , TRequestStatus &) |
EFSRV_IMPORT_C void | ReadCancel ( TRequestStatus &) |
EFSRV_IMPORT_C void | ReadCancel () |
EFSRV_IMPORT_C TInt | Rename (const TDesC &) |
EFSRV_IMPORT_C TInt | Replace ( RFs &, const TDesC &, TUint ) |
EFSRV_IMPORT_C TInt | Seek ( TSeek , TInt &) |
EFSRV_IMPORT_C TInt | Set (const TTime &, TUint , TUint ) |
EFSRV_IMPORT_C TInt | SetAtt ( TUint , TUint ) |
EFSRV_IMPORT_C TInt | SetModified (const TTime &) |
EFSRV_IMPORT_C TInt | SetSize ( TInt ) |
EFSRV_IMPORT_C TInt | Size ( TInt &) |
EFSRV_IMPORT_C TInt | Temp ( RFs &, const TDesC &, TFileName &, TUint ) |
EFSRV_IMPORT_C TInt | TransferToClient (const RMessage2 &, TInt ) |
EFSRV_IMPORT_C TInt | TransferToProcess ( RProcess &, TInt , TInt ) |
EFSRV_IMPORT_C TInt | TransferToServer ( TIpcArgs &, TInt , TInt ) |
EFSRV_IMPORT_C TInt | UnLock ( TInt , TInt ) |
EFSRV_IMPORT_C TInt | Write (const TDesC8 &) |
EFSRV_IMPORT_C void | Write (const TDesC8 &, TRequestStatus &) |
EFSRV_IMPORT_C TInt | Write (const TDesC8 &, TInt ) |
EFSRV_IMPORT_C void | Write (const TDesC8 &, TInt , TRequestStatus &) |
EFSRV_IMPORT_C TInt | Write ( TInt , const TDesC8 &) |
EFSRV_IMPORT_C void | Write ( TInt , const TDesC8 &, TRequestStatus &) |
EFSRV_IMPORT_C TInt | Write ( TInt , const TDesC8 &, TInt ) |
EFSRV_IMPORT_C void | Write ( TInt , const TDesC8 &, TInt , TRequestStatus &) |
Protected Member Functions | |
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void | CloseSubSession ( TInt ) |
TInt | CreateSubSession (const RSessionBase &, TInt , const TIpcArgs &) |
TInt | DuplicateHandle ( TInt &) |
TInt | SendReceive ( TInt , const TIpcArgs &) |
EFSRV_IMPORT_C TInt | Adopt | ( | RFs & | aFs, |
TInt | aHandle | |||
) |
Adopts an already open file.
EFSRV_IMPORT_C TInt | AdoptFromClient | ( | const RMessage2 & | aMsg, |
TInt | aFsHandleIndex, | |||
TInt | aFileHandleIndex | |||
) |
Allows a server to adopt an already open file from a client. The client's RFs and RFile handles are contained in message slots within aMsg.
Assumes that the client's RFs and RFile handles have been sent to the server using TransferToServer() .
This RFile will own it's RFs session so that when the sub-session ( RFile ) is closed so will the RFs session.
EFSRV_IMPORT_C TInt | AdoptFromCreator | ( | TInt | aFsIndex, |
TInt | aFileHandleIndex | |||
) |
Allows a server to adopt an already open file from a client process. The client's file-server ( RFs ) and file ( RFile ) handles are contained in this process's environment data slots.
Assumes that the client's RFs and RFile handles have been sent to the server process using TransferToProcess() .
This RFile will own it's RFs session so that when the sub-session ( RFile ) is closed so will the RFs session.
TInt aFsIndex | An index that identifies the slot in the process environment data that contains the file server session (RFs) handle |
TInt aFileHandleIndex | An index that identifies the slot in the process environment data that contains the sub-session (RFile) handle of the already opened file |
EFSRV_IMPORT_C TInt | AdoptFromServer | ( | TInt | aFsHandle, |
TInt | aFileHandle | |||
) |
EFSRV_IMPORT_C TInt | Att | ( | TUint & | aAttValue | ) | const |
Gets the file's attributes.
TUint & aAttValue | A bitmask which, on return, contains the file s attributes. For more information, see KEntryAttNormal and the other file/directory attributes. |
EFSRV_IMPORT_C TInt | BlockMap | ( | SBlockMapInfo & | aInfo, |
TInt64 & | aStartPos, | |||
TInt64 | aEndPos = -1, | |||
TInt | aBlockMapusage = EBlockMapUsagePaging | |||
) | const |
Fetches the Block Map of a file. Each file in the file system will consist of a number of groups of blocks. Each group represents a number of contiguous blocks. Such a group is represented by the TBlockMapEntry class. The full Block Map representing the file may be determined by repeatedly calling RFile::BlockMap until KErrCompletion is returned.
Note:
1. If the Block Map for the whole file is not required, then a start and end position for a section of the file can be specified. Both of these parameters specify offsets from the start of the file in bytes.
SBlockMapInfo & aInfo | A structure describing a group of block maps. |
TInt64 & aStartPos | A start position for a desired section of the file. |
TInt64 aEndPos = -1 | An end position for a desired section of the file. If not passed, then the end of the file is assumed. |
TInt aBlockMapusage = EBlockMapUsagePaging |
EFSRV_IMPORT_C TInt | ChangeMode | ( | TFileMode | aNewMode | ) |
Switches an open file's access mode between EFileShareExclusive and EFileShareReadersOnly.
This allows or disallows read-only access without having to close and re-open the file.
TFileMode aNewMode | The new access mode. |
TInt | Clamp | ( | RFileClamp & | aHandle | ) |
Instructs the File Server that the file is not to be modified on storage media.
RFileClamp & aHandle | On return, a handle to the file. |
EFSRV_IMPORT_C void | Close | ( | ) |
Closes the file.
Any open files are closed when the file server session is closed.
Close() is guaranteed to return, and provides no indication whether it completed successfully or not. When closing a file you have written to, you should ensure that data is committed to the file by invoking RFile::Flush() before closing. If Flush() completes successfully, Close() is essentially a no-operation.
EFSRV_IMPORT_C TInt | Create | ( | RFs & | aFs, |
const TDesC & | aName, | |||
TUint | aFileMode | |||
) |
Creates and opens a new file for writing.
If the file already exists, an error is returned.
If the resulting path does not exist, then the operation cannot proceed and the function returns an error code.
Notes:
1. To close the file, use Close()
2. It automatically sets the file's archive attribute.
RFs & aFs | The file server session. |
const TDesC & aName | The name of the file. Any path components (i.e. drive letter or directory), which are not specified, are taken from the session path. The file name shall not contain wild cards ('?' or '*' characters) and illegal characters like '<', '>', ':', '"', '/', '|' and ''. Backslash '\' character is allowed only as a path delimiter. The filename containing only white space characters (See TChar::IsSpace()) is also illegal. |
TUint aFileMode | The mode in which the file is opened. The access mode is automatically set to EFileWrite. See TFileMode. |
TInt | CreateSubSession | ( | const RSessionBase & | aSession, |
TInt | aFunction, | |||
const TIpcArgs & | aArgs | |||
) | [protected] |
Creates a new sub-session within an existing session.
const RSessionBase & aSession | The session to which this sub-session will belong. |
TInt aFunction | The opcode specifying the requested service; the server should interpret this as a request to create a sub-session. |
const TIpcArgs & aArgs | The message arguments. |
EFSRV_IMPORT_C TInt | Drive | ( | TInt & | aDriveNumber, |
TDriveInfo & | aDriveInfo | |||
) | const |
Gets information about the drive on which this file resides.
TInt & aDriveNumber | On return, the drive number. |
TDriveInfo & aDriveInfo | On return, contains information describing the drive and the medium mounted on it. The value of TDriveInfo::iType shows whether the drive contains media. |
EFSRV_IMPORT_C TInt | Duplicate | ( | const RFile & | aFile, |
TOwnerType | aType = EOwnerProcess | |||
) |
Make a duplicate of the passed file handle in the same thread.
By default, any thread in the process can use the duplicated handle to access the file. However, specifying EOwnerThread as the second parameter to this function, means that only the creating thread can use the handle.
const RFile & aFile | The file handle to duplicate |
TOwnerType aType = EOwnerProcess | An enumeration whose enumerators define the ownership of this handle. If not explicitly specified, EOwnerProcess is taken as default. |
TInt | DuplicateHandle | ( | TInt & | aSubSessionHandle | ) | const [protected] |
TInt & aSubSessionHandle |
EFSRV_IMPORT_C TInt | Flush | ( | ) |
Commits data to the storage device and flushes internal buffers without closing the file.
Although RFile::Close() also flushes internal buffers, it is often useful to call Flush() before a file is closed. This is because Close() returns no error information, so there is no way of telling whether the final data was written to the file successfully or not. Once data has been flushed, Close() is effectively a no-operation.
EFSRV_IMPORT_C void | Flush | ( | TRequestStatus & | aStatus | ) |
Commits data to the storage device and flushes internal buffers without closing the file.
Although RFile::Close() also flushes internal buffers, it is often useful to call Flush() before a file is closed. This is because Close() returns no error information, so there is no way of telling whether the final data was written to the file successfully or not. Once data has been flushed, Close() is effectively a no-operation.
TRequestStatus & aStatus | Request status. On completion contains KErrNone if successful, otherwise one of the other system-wide error codes. |
EFSRV_IMPORT_C TInt | FullName | ( | TDes & | aName | ) | const |
Gets the full filename
This is used to retrieve the full filename, including drive and path, of a file that has been passed from one process to another using the RFile::AdoptXXX() methods.
TDes & aName | On return, contains the full name of the file, including drive and path. |
EFSRV_IMPORT_C TInt | Lock | ( | TInt | aPos, |
TInt | aLength | |||
) | const |
Locks a region within the file as defined by a range of bytes.
This ensures that those bytes are accessible only through the RFile object which claims the lock. To re-allow access by other programs to the locked region, it must either be unlocked or the file closed. Locking can be used to synchronize operations on a file when more than one program has access to the file in EFileShareAny mode.
More than one distinct region of a file can be locked, but an error is returned if more than one lock is placed on the same region. Different RFile objects can lock different parts of the same file as long as the file is opened in EFileShareAny mode. The locked region may extend beyond the end of a file; this prevents the file from being extended by other programs.
EFSRV_IMPORT_C TInt | Modified | ( | TTime & | aTime | ) | const |
Gets local date and time the file was last modified, in universal time.
TTime & aTime | On return, contains the date and time the file was last modified in UTC. |
EFSRV_IMPORT_C TInt | Name | ( | TDes & | aName | ) | const |
Gets the final part of a filename
This is used to retrieve the name and extension of a file that has been passed from one process to another using the RFile::AdoptXXX() methods.
TDes & aName | On return, contains the name of the file, including the name and extension but excluding the drive letter and path. |
EFSRV_IMPORT_C TInt | Open | ( | RFs & | aFs, |
const TDesC & | aName, | |||
TUint | aFileMode | |||
) |
Opens an existing file for reading or writing.
If the file does not already exist, an error is returned.
Notes:
1. To close the file, use Close()
2. Attempting to open a file with the read-only attribute using the EFileWrite access mode results in an error.
3. Attempting to open a file which is greater than or equal to 2GByte (2,147,483,648 bytes) will fail with KErrTooBig
4. After a file has been opened, the current write position is set to the start of the file. If necessary, use RFile::Seek() to move to a different position within the file.
RFs & aFs | The file server session. |
const TDesC & aName | The name of the file. Any path components (i.e. drive letter or directory), which are not specified, are taken from the session path.The file name shall not contain wild cards ('?' or '*' characters) and illegal characters like '<', '>', ':', '"', '/', '|' and ''. Backslash '\' character is allowed only as a path delimiter. The filename containing only white space characters (See TChar::IsSpace()) is also illegal. |
TUint aFileMode | The mode in which the file is opened. See TFileMode. |
EFSRV_IMPORT_C TInt | Read | ( | TDes8 & | aDes | ) | const |
Reads from the file at the current position.
This is a synchronous function.
Note that when an attempt is made to read beyond the end of the file, no error is returned. The descriptor's length is set to the number of bytes read into it. Therefore, when reading through a file,the end of file has been reached when the descriptor length, as returned by TDesC8::Length() , is zero.
TDes8 & aDes | Descriptor into which binary data is read. Any existing contents are overwritten. On return, its length is set to the number of bytes read. |
EFSRV_IMPORT_C void | Read | ( | TDes8 & | aDes, |
TRequestStatus & | aStatus | |||
) | const |
Reads from the file at the current position.
This is an asynchronous function.
Note that when an attempt is made to read beyond the end of the file, no error is returned. The descriptor's length is set to the number of bytes read into it. Therefore, when reading through a file,the end of file has been reached when the descriptor length, as returned by TDesC8::Length() , is zero.
TDes8 & aDes | Descriptor into which binary data is read. Any existing contents are overwritten. On return, its length is set to the number of bytes read. NB: this function is asynchronous and the request that it represents may not complete until some time after the call to the function has returned. It is important, therefore, that this descriptor remain valid, or remain in scope, until you have been notified that the request is complete. |
TRequestStatus & aStatus | Request status. On completion contains: KErrNone, if successful, otherwise one of the other system-wide error codes. |
EFSRV_IMPORT_C TInt | Read | ( | TDes8 & | aDes, |
TInt | aLength | |||
) | const |
Reads the specified number of bytes of binary data from the file at the current position.
This is a synchronous function.
Note that when an attempt is made to read beyond the end of the file, no error is returned. The descriptor's length is set to the number of bytes read into it. Therefore, when reading through a file,the end of file has been reached when the descriptor length, as returned by TDesC8::Length() , is zero. Assuming aLength is less than the maximum length of the descriptor, the only circumstances in which Read() can return fewer bytes than requested, is when the end of file is reached or if an error occurs.
TDes8 & aDes | Descriptor into which binary data is read. Any existing contents are overwritten. On return, its length is set to the number of bytes read. |
TInt aLength | The number of bytes to be read from the file into the descriptor. If an attempt is made to read more bytes than the descriptor's maximum length, the function returns KErrOverflow. This value must not be negative, otherwise the function returns KErrArgument. |
EFSRV_IMPORT_C void | Read | ( | TDes8 & | aDes, |
TInt | aLength, | |||
TRequestStatus & | aStatus | |||
) | const |
Reads a specified number of bytes of binary data from the file at the current position.
This is an asynchronous function.
Note that when an attempt is made to read beyond the end of the file, no error is returned. The descriptor's length is set to the number of bytes read into it. Therefore, when reading through a file, the end of file has been reached when the descriptor length, as returned by TDesC8::Length() , is zero. Assuming aLength is less than the maximum length of the descriptor, the only circumstances in which Read() can return fewer bytes than requested is when the end of file is reached or if an error has occurred.
TDes8 & aDes | Descriptor into which binary data is read. Any existing contents are overwritten. On return, its length is set to the number of bytes read. NB: this function is asynchronous and the request that it represents may not complete until some time after the call to the function has returned. It is important, therefore, that this descriptor remain valid, or remain in scope, until you have been notified that the request is complete. |
TInt aLength | The number of bytes to be read from the file into the descriptor. If an attempt is made to read more bytes than the descriptor's maximum length, then the function updates aStatus parameter with KErrOverflow. It must not be negative otherwise the function updates aStatus with KErrArgument. |
TRequestStatus & aStatus | Request status. On completion contains KErrNone if successful, otherwise one of the other system-wide error codes. |
EFSRV_IMPORT_C TInt | Read | ( | TInt | aPos, |
TDes8 & | aDes | |||
) | const |
Reads from the file at the specified offset within the file
This is a synchronous function.
Note that when an attempt is made to read beyond the end of the file, no error is returned. The descriptor's length is set to the number of bytes read into it. Therefore, when reading through a file, the end of file has been reached when the descriptor length, as returned by TDesC8::Length() , is zero.
TInt aPos | Position of first byte to be read. This is an offset from the start of the file. If no position is specified, reading begins at the current file position. If aPos is beyond the end of the file, the function returns a zero length descriptor. |
TDes8 & aDes | The descriptor into which binary data is read. Any existing content is overwritten. On return, its length is set to the number of bytes read. |
EFSRV_IMPORT_C void | Read | ( | TInt | aPos, |
TDes8 & | aDes, | |||
TRequestStatus & | aStatus | |||
) | const |
Reads from the file at the specified offset within the file.
This is an asynchronous function.
Note that when an attempt is made to read beyond the end of the file, no error is returned. The descriptor's length is set to the number of bytes read into it. Therefore, when reading through a file, the end of file has been reached when the descriptor length, as returned by TDesC8::Length() , is zero.
TInt aPos | Position of first byte to be read. This is an offset from the start of the file. If no position is specified, reading begins at the current file position. If aPos is beyond the end of the file, the function returns a zero length descriptor. |
TDes8 & aDes | The descriptor into which binary data is read. Any existing content is overwritten. On return, its length is set to the number of bytes read. NB: this function is asynchronous and the request that it represents may not complete until some time after the call to the function has returned. It is important, therefore, that this descriptor remain valid, or remain in scope, until you have been notified that the request is complete. |
TRequestStatus & aStatus | The request status. On completion, contains an error code of KErrNone if successful, otherwise one of the other system-wide error codes. |
EFSRV_IMPORT_C TInt | Read | ( | TInt | aPos, |
TDes8 & | aDes, | |||
TInt | aLength | |||
) | const |
Reads the specified number of bytes of binary data from the file at a specified offset within the file.
This is a synchronous function.
Note that when an attempt is made to read beyond the end of the file, no error is returned. The descriptor's length is set to the number of bytes read into it. Therefore, when reading through a file, the end of file has been reached when the descriptor length, as returned by TDesC8::Length() , is zero. Assuming aLength is less than the maximum length of the descriptor, the only circumstances in which Read() can return fewer bytes than requested is when the end of file is reached or if an error has occurred.
TInt aPos | Position of first byte to be read. This is an offset from the start of the file. If no position is specified, reading begins at the current file position. If aPos is beyond the end of the file, the function returns a zero length descriptor. |
TDes8 & aDes | The descriptor into which binary data is read. Any existing contents are overwritten. On return, its length is set to the number of bytes read. |
TInt aLength | The number of bytes to read from the file into the descriptor. If an attempt is made to read more bytes than the descriptor's maximum length, then the function updates aStatus parameter with KErrOverflow. It must not be negative otherwise the function updates aStatus with KErrArgument. |
EFSRV_IMPORT_C void | Read | ( | TInt | aPos, |
TDes8 & | aDes, | |||
TInt | aLength, | |||
TRequestStatus & | aStatus | |||
) | const |
Reads the specified number of bytes of binary data from the file at a specified offset within the file.
This is an asynchronous function.
Note that when an attempt is made to read beyond the end of the file, no error is returned. The descriptor's length is set to the number of bytes read into it. Therefore, when reading through a file, the end of file has been reached when the descriptor length, as returned by TDesC8::Length() , is zero. Assuming aLength is less than the maximum length of the descriptor, the only circumstances in which Read() can return fewer bytes than requested is when the end of file is reached or if an error has occurred.
TInt aPos | Position of first byte to be read. This is an offset from the start of the file. If no position is specified, reading begins at the current file position. If aPos is beyond the end of the file, the function returns a zero length descriptor. |
TDes8 & aDes | The descriptor into which binary data is read. Any existing contents are overwritten. On return, its length is set to the number of bytes read. NB: this function is asynchronous and the request that it represents may not complete until some time after the call to the function has returned. It is important, therefore, that this descriptor remain valid, or remain in scope, until you have been notified that the request is complete. |
TInt aLength | The number of bytes to read from the file into the descriptor. If an attempt is made to read more bytes than the descriptor's maximum length, then the function returns KErrOverflow. It must not be negative otherwise the function returns KErrArgument. |
TRequestStatus & aStatus | Request status. On completion contains KErrNone if successful, otherwise one of the other system-wide error codes. |
EFSRV_IMPORT_C void | ReadCancel | ( | TRequestStatus & | aStatus | ) | const |
Cancels a specific outstanding asynchronous read request.
The outstanding request completes with KErrCancel.
TRequestStatus & aStatus |
EFSRV_IMPORT_C void | ReadCancel | ( | ) | const |
Cancels all outstanding asynchronous read requests for this subsession.
All outstanding requests complete with KErrCancel.
EFSRV_IMPORT_C TInt | Rename | ( | const TDesC & | aNewName | ) |
Renames a file.
If aNewName specifies a different directory to the one in which the file is currently located, then the file is moved.
No other process may have access to the file, that is, the file must have been opened in EFileShareExclusive share mode, or an error is returned. The file must have been opened for writing (using EFileWrite access mode). An error is returned if a file with the new filename already exists in the target directory.
The file or directory may not be moved to another device by this means, either explicitly (by another drive specified in the name) or implicitly (because the directory has been mapped to another device with RFs::SetSubst() ).
Note that the function builds up the new file specification by using all of the path components specified in aNewName (directory path, filename and extension), then adding any missing components from the current file specification, and finally adding any missing components from the session path. A consequence of this is that you cannot rename a file to remove its extension. An alternative to this function is RFs::Rename() which renames the file using the new name as provided.
const TDesC & aNewName | The new file name and/or directory path. No part may contain wildcard characters or an error is returned. |
EFSRV_IMPORT_C TInt | Replace | ( | RFs & | aFs, |
const TDesC & | aName, | |||
TUint | aFileMode | |||
) |
Opens a file for writing, replacing the content of any existing file of the same name if it exists, or creating a new file if it does not exist.
If the resulting path exists, then:
the length of an existing file with the same filename is re-set to zero
a new file is created, if no existing file with the same filename can be found.
If the resulting path does not exist, then the operation cannot proceed and the function returns an error code.
Notes:
To close the file, use Close() , defined in the base class RFsBase.
It automatically sets the file's archive attribute.
RFs & aFs | The file server session. |
const TDesC & aName | The name of the file. Any path components (i.e. drive letter or directory), which are not specified, are taken from the session path. The file name shall not contain wild cards ('?' or '*' characters) and illegal characters like '<', '>', ':', '"', '/', '|' and ''. Backslash '\' character is allowed only as a path delimiter. The filename containing only white space characters (See TChar::IsSpace()) is also illegal. |
TUint aFileMode | The mode in which the file is opened. The access mode is automatically set to EFileWrite. See TFileMode. |
EFSRV_IMPORT_C TInt | Seek | ( | TSeek | aMode, |
TInt & | aPos | |||
) | const |
Sets the the current file position.
The function can also be used to get the current file position without changing it. The file position is the position at which reading and writing takes place. The start of the file is position zero.
To retrieve the current file position without changing it, specify ESeekCurrent for the seek mode, and zero for the offset.
If the seek mode is ESeekStart, then:
1. the function does not modify the aPos argument,
2. the function returns an error if the offset specified is negative.
If the seek mode is ESeekAddress, an error is returned if:
1. the file is not in ROM,
2. the offset specified is greater than the size of the file.
TSeek aMode | Seek mode. Controls the destination of the seek operation. |
TInt & aPos | Offset from location specified in aMode. Can be negative. On return contains the new file position. If the seek mode is either ESeekCurrent or ESeekEnd and the offset specifies a position before the start of the file or beyond the end of the file, then on return, aPos is set to the new file position (either the start or the end of the file). If the seek mode is ESeekAddress, aPos returns the address of the byte at the specified offset within the file. |
TInt | SendReceive | ( | TInt | aFunction, |
const TIpcArgs & | aArgs | |||
) | const [protected] |
Sends a message to the server and waits synchronously for a reply.
An opcode specifies the service required. A set of message arguments is passed that can be used to specify client addresses, which the server can use to read from and write to the client address space.
Note that this function will only fail if the server itself fails or environmental errors occur in the server. All requests made using this function are guaranteed to reach the server. This means that all synchronous client requests (typically those that return void) should be routed through this synchronous variant of SendReceive() .
EFSRV_IMPORT_C TInt | Set | ( | const TTime & | aTime, |
TUint | aSetAttMask, | |||
TUint | aClearAttMask | |||
) |
Sets the file s attributes, and the date and time it was last modified.
It combines the functionality of SetAtt() and SetModified()
An attempt to set or clear the KEntryAttDir, KEntryAttVolume or KEntryAttRemote attributes have no effect.
const TTime & aTime | The new date and time the file was last modified. UTC date and time should be used. |
TUint aSetAttMask | A bitmask indicating the file attributes to be set |
TUint aClearAttMask | A bitmask indicating the attributes to be cleared. For more information see KEntryAttNormal, and the other file/directory attributes. |
EFSRV_IMPORT_C TInt | SetAtt | ( | TUint | aSetAttMask, |
TUint | aClearAttMask | |||
) |
Sets or clears file attributes using two bitmasks.
The first mask controls which attributes are set. The second controls which attributes are cleared.
Notes:
1. The file must have been opened for writing, or an error is returned.
2. A panic is raised if any attribute is specified in both bitmasks.
3. An attempt to set or clear the KEntryAttDir, KEntryAttVolume or KEntryAttRemote attributes have no effect.
4. The new attribute values take effect when the file is flushed or closed (which implies a flush).
EFSRV_IMPORT_C TInt | SetModified | ( | const TTime & | aTime | ) |
Sets the date and time the file was last modified. UTC date and time should be used.
Notes:
1. The file must have been opened for writing, or an error is returned.
2. The new modified time takes effect when the file is flushed or closed (which implies a flush).
const TTime & aTime | The new date and time the file was last modified, in universal time. |
EFSRV_IMPORT_C TInt | SetSize | ( | TInt | aSize | ) |
Sets the file size.
If the size of the file is reduced, data may be lost from the end of the file.
Note:
1. The current file position remains unchanged unless SetSize() reduces the size of the file in such a way that the current file position is now beyond the end of the file. In this case, the current file position is set to the end of file.
2. If the file was not opened for writing, an error is returned.
TInt aSize | The new size of the file, in bytes. This value must not be negative, otherwise the function raises a panic. |
EFSRV_IMPORT_C TInt | Size | ( | TInt & | aSize | ) | const |
Gets the current file size.
TInt & aSize | On return, the size of the file in bytes. |
EFSRV_IMPORT_C TInt | Temp | ( | RFs & | aFs, |
const TDesC & | aPath, | |||
TFileName & | aName, | |||
TUint | aFileMode | |||
) |
Creates and opens a temporary file with a unique name for writing and reading.
Notes:
1. To close the file, use Close()
RFs & aFs | The file server session. |
const TDesC & aPath | The directory in which the file is created. |
TFileName & aName | On return, contains the full path and file name of the file. The filename is guaranteed to be unique within the directory specified by aPath. |
TUint aFileMode | The mode in which the file is opened. The access mode is automatically set to EFileWrite. See TFileMode. |
EFSRV_IMPORT_C TInt | TransferToClient | ( | const RMessage2 & | aMsg, |
TInt | aFileHandleIndex | |||
) | const |
Transfers an already open file from a server to a client.
Before this function can be called, the file server session which owns this file handle must first be marked as shareable by calling RFs::ShareProtected() .
The file ( RFile ) handle is written to the client's address space to the package buffer in the message address slot in aMsg identified by aFileHandleIndex.
If no error occurs, then the message is completed with the file-server ( RFs ) session handle.
When the message completes, the client may call AdoptFromServer() to open a new RFile object which refers to the same file as this.
Note that if an error occurs then the message is not completed.
EFSRV_IMPORT_C TInt | TransferToProcess | ( | RProcess & | aProcess, |
TInt | aFsHandleIndex, | |||
TInt | aFileHandleIndex | |||
) | const |
Transfers an already open file to another process.
Before this function can be called, the file server session which owns this file handle must first be marked as shareable by calling RFs::ShareProtected() .
This function packages handle details for this file into 2 arguments in another process's environment data slots. When the other process runs, it may call AdoptFromCreator() to open a new RFile object which refers to the same file as this.
RProcess & aProcess | A handle to another process. |
TInt aFsHandleIndex | An index that identifies a slot in the process's environment data which on exit will contain the file server session (RFs) handle This slot must not be used for anything else otherwise the results will be unpredictable. |
TInt aFileHandleIndex | An index that identifies a slot in the process's environment data which on exit will contain the file (RFile) handle. This slot must not be used for anything else otherwise the results will be unpredictable. |
EFSRV_IMPORT_C TInt | TransferToServer | ( | TIpcArgs & | aIpcArgs, |
TInt | aFsHandleIndex, | |||
TInt | aFileHandleIndex | |||
) | const |
Transfers an already open file to a server.
Before this function can be called, the file server session which owns this file handle must first be marked as shareable by calling RFs::ShareProtected() .
This function packages handle details for this file into 2 arguments of a TIpcArgs object. When these arguments are sent in an IPC message, the server which receives them may call AdoptFromClient() to open a new RFile object which refers to the same file as this.
TIpcArgs & aIpcArgs | The IPC message arguments. |
TInt aFsHandleIndex | An index that identifies an argument in aIpcArgs where the file server session handle will be stored. This argument must not be used for anything else otherwise the results will be unpredictable. |
TInt aFileHandleIndex | An index that identifies an argument in aIpcArgs where the file handle will be stored. This argument must not be used for anything else otherwise the results will be unpredictable. |
EFSRV_IMPORT_C TInt | UnLock | ( | TInt | aPos, |
TInt | aLength | |||
) | const |
Unlocks a region within the file as defined by a range of bytes.
A lock can only be removed by the RFile object which claimed the lock.
A portion of a locked region cannot be unlocked. The entire locked region must be unlocked otherwise an error is returned. If any byte within the specified range of bytes to unlock is not locked, an error is returned.
EFSRV_IMPORT_C TInt | Write | ( | const TDesC8 & | aDes | ) |
Writes to the file at the current offset within the file.
This is a synchronous function.
NB Attempting to extend the file to 2 GByte or greater will fail with KErrTooBig
const TDesC8 & aDes | The descriptor from which binary data is written. The function writes the entire contents of aDes to the file. |
EFSRV_IMPORT_C void | Write | ( | const TDesC8 & | aDes, |
TRequestStatus & | aStatus | |||
) |
Writes to the file at the current offset within the file.
This is an asynchronous function.
NB Attempting to extend the file to 2 GByte or greater will fail with KErrTooBig
const TDesC8 & aDes | The descriptor from which binary data is written. The function writes the entire contents of aDes to the file. NB: this function is asynchronous and the request that it represents may not complete until some time after the call to the function has returned. It is important, therefore, that this descriptor remain valid, or remain in scope, until you have been notified that the request is complete. |
TRequestStatus & aStatus | Request status. On completion contains KErrNone if successful, otherwise one of the other system-wide error codes. |
EFSRV_IMPORT_C TInt | Write | ( | const TDesC8 & | aDes, |
TInt | aLength | |||
) |
Writes a portion of a descriptor to the file at the current offset within the file.
This is a synchronous function.
NB Attempting to extend the file to 2 GByte or greater will fail with KErrTooBig
EFSRV_IMPORT_C void | Write | ( | const TDesC8 & | aDes, |
TInt | aLength, | |||
TRequestStatus & | aStatus | |||
) |
Writes a portion of a descriptor to the file at the current offset within the file.
This is an asynchronous function.
NB Attempting to extend the file to 2 GByte or greater will fail with KErrTooBig
const TDesC8 & aDes | The descriptor from which binary data is written. NB: this function is asynchronous and the request that it represents may not complete until some time after the call to the function has returned. It is important, therefore, that this descriptor remain valid, or remain in scope, until you have been notified that the request is complete. |
TInt aLength | The number of bytes to be written from the descriptor. This must not be greater than the length of the descriptor. It must not be negative. |
TRequestStatus & aStatus | Request status. On completion contains KErrNone if successful; KErrArgument if aLength is negative; otherwise one of the other system-wide error codes. |
EFSRV_IMPORT_C TInt | Write | ( | TInt | aPos, |
const TDesC8 & | aDes | |||
) |
Writes to the file at the specified offset within the file
This is a synchronous function.
NB Attempting to extend the file to 2 GByte or greater will fail with KErrTooBig
TInt aPos | The offset from the start of the file at which the first byte is written. If a position beyond the end of the file is specified, then the write operation begins at the end of the file. If the position has been locked, then the write fails. |
const TDesC8 & aDes | The descriptor from which binary data is written. The function writes the entire contents of aDes to the file. |
EFSRV_IMPORT_C void | Write | ( | TInt | aPos, |
const TDesC8 & | aDes, | |||
TRequestStatus & | aStatus | |||
) |
Writes to the file at the specified offset within the file
This is an asynchronous function.
NB Attempting to extend the file to 2 GByte or greater will fail with KErrTooBig
TInt aPos | The offset from the start of the file at which the first byte is written. If a position beyond the end of the file is specified, then the write operation begins at the end of the file. If the position has been locked, then the write fails. |
const TDesC8 & aDes | The descriptor from which binary data is written. The function writes the entire contents of aDes to the file. NB: this function is asynchronous and the request that it represents may not complete until some time after the call to the function has returned. It is important, therefore, that this descriptor remain valid, or remain in scope, until you have been notified that the request is complete. |
TRequestStatus & aStatus | Request status. On completion contains KErrNone if successful, otherwise one of the other system-wide error codes. |
EFSRV_IMPORT_C TInt | Write | ( | TInt | aPos, |
const TDesC8 & | aDes, | |||
TInt | aLength | |||
) |
Writes the specified number of bytes to the file at the specified offset within the file.
This is a synchronous function.
NB Attempting to extend the file to 2 GByte or greater will fail with KErrTooBig
TInt aPos | The offset from the start of the file at which the first byte is written. If a position beyond the end of the file is specified, then the write operation begins at the end of the file. If the position has been locked, then the write fails. |
const TDesC8 & aDes | The descriptor from which binary data is written. |
TInt aLength | The number of bytes to be written from aDes . It must not be negative. |
EFSRV_IMPORT_C void | Write | ( | TInt | aPos, |
const TDesC8 & | aDes, | |||
TInt | aLength, | |||
TRequestStatus & | aStatus | |||
) |
Writes the specified number of bytes to the file at the specified offset within the file.
This is an asynchronous function.
NB Attempting to extend the file to 2 GByte or greater will fail with KErrTooBig
TInt aPos | The offset from the start of the file at which the first byte is written. If a position beyond the end of the file is specified, then the write operation begins at the end of the file. If the position has been locked, then the write fails. |
const TDesC8 & aDes | The descriptor from which binary data is written. NB: this function is asynchronous and the request that it represents may not complete until some time after the call to the function has returned. It is important, therefore, that this descriptor remain valid, or remain in scope, until you have been notified that the request is complete. |
TInt aLength | The number of bytes to be written from aDes. It must not be negative. |
TRequestStatus & aStatus | Request status. On completion contains KErrNone if successful; KErrArgument if aLength is negative; otherwise one of the other system-wide error codes. |
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reserved. Unless otherwise stated, these materials are provided under the terms of the Eclipse Public License
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