FileAccess Lianja Reference Documentation

FileAccess

Current Version: 9.5.0.98

API for reading and writing files, creating and deleting directories, deleting directory trees, splitting and re-joining large files, etc. This is a freeware class. The reason for its existence is that in some programming languages, file I/O API's are limited or difficult to understand/use. This API provides an identical FILE I/O API across all programming languages supported by Chilkat.

Object Creation

loObject = createobject("CkFileAccess")

Properties

CurrentDir
CurrentDir As Character (read-only)

The current working directory of the calling process.

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DebugLogFilePath
DebugLogFilePath As Character

If set to a file path, causes each Chilkat method or property call to automatically append it's LastErrorText to the specified log file. The information is appended such that if a hang or crash occurs, it is possible to see the context in which the problem occurred, as well as a history of all Chilkat calls up to the point of the problem. The VerboseLogging property can be set to provide more detailed information.

This property is typically used for debugging the rare cases where a Chilkat method call hangs or generates an exception that halts program execution (i.e. crashes). A hang or crash should generally never happen. The typical causes of a hang are:

  1. a timeout related property was set to 0 to explicitly indicate that an infinite timeout is desired,
  2. the hang is actually a hang within an event callback (i.e. it is a hang within the application code), or
  3. there is an internal problem (bug) in the Chilkat code that causes the hang.

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EndOfFile
EndOfFile As Boolean (read-only)

Returns .T. if the current open file is at the end-of-file.

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FileOpenError
FileOpenError As Numeric (read-only)

This property is set by the following methods: FileOpen, OpenForRead, OpenForWrite, OpenForReadWrite, and OpenForAppend. It provides an error code indicating the failure reason. Possible values are:

  1. Success (No error)
  2. Access denied.
  3. File not found.
  4. General (non-specific) open error.
  5. File aleady exists.
  6. Path refers to a directory and the access requested involves writing.
  7. Too many symbolic links were encountered in resolving path.
  8. The process already has the maximum number of files open.
  9. Pathname is too long.
  10. The system limit on the total number of open files has been reached.
  11. Pathname refers to a device special file and no corresponding device exists.
  12. Insufficient kernel memory was available.
  13. Pathname was to be created but the device containing pathname has no room for the new file.
  14. A component used as a directory in pathname is not, in fact, a directory.
  15. Pathname refers to a regular file, too large to be opened (this would be a limitation of the underlying operating system, not a limitation imposed by Chilkat).
  16. Pathname refers to a file on a read-only filesystem and write access was requested.

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FileOpenErrorMsg
FileOpenErrorMsg As Character (read-only)

The error message text associated with the FileOpenError code.

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LastErrorHtml
LastErrorHtml As Character (read-only)

Provides information in HTML format about the last method/property called. If a method call returns a value indicating failure, or behaves unexpectedly, examine this property to get more information.

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LastErrorText
LastErrorText As Character (read-only)

Provides information in plain-text format about the last method/property called. If a method call returns a value indicating failure, or behaves unexpectedly, examine this property to get more information.

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LastErrorXml
LastErrorXml As Character (read-only)

Provides information in XML format about the last method/property called. If a method call returns a value indicating failure, or behaves unexpectedly, examine this property to get more information.

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LastMethodSuccess
LastMethodSuccess As Boolean

Indicate whether the last method call succeeded or failed. A value of .T. indicates success, a value of .F. indicates failure. This property is automatically set for method calls. It is not modified by property accesses. The property is automatically set to indicate success for the following types of method calls:

  • Any method that returns a string.
  • Any method returning a Chilkat object, binary bytes, or a date/time.
  • Any method returning a standard boolean status value where success = .T. and failure = .F..
  • Any method returning an integer where failure is defined by a return value less than zero.

Note: Methods that do not fit the above requirements will always set this property equal to .T.. For example, a method that returns no value (such as a "void" in C++) will technically always succeed.

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LockFileOnOpen
LockFileOnOpen As Boolean
Introduced in version 9.5.0.80

Note: This property only applies for applications running on Windows.

If .T., then the following methods open files for exclusive-access: OpenForAppend, OpenForRead, OpenForReadWrite, OpenForWrite. When a file is opened for exclusive access, it is locked so that no other process may open the file. When the file is closed, the lock is released.

The default value of this property is .F..

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VerboseLogging
VerboseLogging As Boolean

If set to .T., then the contents of LastErrorText (or LastErrorXml, or LastErrorHtml) may contain more verbose information. The default value is .F.. Verbose logging should only be used for debugging. The potentially large quantity of logged information may adversely affect peformance.

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Version
Version As Character (read-only)

Version of the component/library, such as "9.5.0.94"

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Methods

AppendAnsi
AppendAnsi(text As Character) As Boolean

Appends a string using the ANSI character encoding to the currently open file.

Returns .T. for success, .F. for failure.

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AppendBd
AppendBd(bd As CkBinData) As Boolean
Introduced in version 9.5.0.76

Appends the contents of bd to the currently open file.

Returns .T. for success, .F. for failure.

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AppendSb
AppendSb(sb As CkStringBuilder, charset As Character) As Boolean
Introduced in version 9.5.0.76

Appends the contents of sb using the character encoding (such as "utf-8") specified by charset to the currently open file.

Returns .T. for success, .F. for failure.

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AppendText
AppendText(str As Character, charset As Character) As Boolean

Appends a string using the character encoding specified by str to the currently open file.

Returns .T. for success, .F. for failure.

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AppendUnicodeBOM
AppendUnicodeBOM() As Boolean

Appends the 2-byte Unicode BOM (little endian) to the currently open file.

Returns .T. for success, .F. for failure.

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AppendUtf8BOM
AppendUtf8BOM() As Boolean

Appends the 3-byte utf-8 BOM to the currently open file.

Returns .T. for success, .F. for failure.

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DirAutoCreate
DirAutoCreate(filePath As Character) As Boolean

Same as DirEnsureExists, except the argument is a file path (the last part of the path is a filename and not a directory). Creates all missing directories such that filePath may be created.

Returns .T. for success, .F. for failure.

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DirCreate
DirCreate(dirPath As Character) As Boolean

Creates a new directory specified by dirPath.

Returns .T. for success, .F. for failure.

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DirDelete
DirDelete(dirPath As Character) As Boolean

Deletes the directory specified by dirPath. It is only possible to delete a directory if it contains no files or subdirectories.

Returns .T. for success, .F. for failure.

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DirEnsureExists
DirEnsureExists(dirPath As Character) As Boolean

Creates all directories necessary such that the entire dirPath exists.

Returns .T. for success, .F. for failure.

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FileClose
FileClose()

Closes the currently open file.

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FileContentsEqual
FileContentsEqual(filePath1 As Character, filePath2 As Character) As Boolean

Compares the contents of two files and returns .T. if they are equal and otherwise returns .F.. The actual contents of the files are only compared if the sizes are equal. The files are not entirely loaded into memory. Instead, they are compared chunk by chunk. This allows for any size files to be compared, regardless of the memory capacity of the computer.

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FileCopy
FileCopy(existingFilepath As Character, newFilepath As Character, failIfExists As Boolean) As Boolean

Copys existingFilepath to newFilepath. If failIfExists is .T. and newFilepath already exists, then an error is returned.

Returns .T. for success, .F. for failure.

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FileDelete
FileDelete(filePath As Character) As Boolean

Deletes the file specified by filePath.

Returns .T. for success, .F. for failure.

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FileExists
FileExists(filePath As Character) As Boolean

Returns .T. if filePath exists, otherwise returns .F..

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FileExists3
FileExists3(path As Character) As Numeric
Introduced in version 9.5.0.45

Returns 1 if the file exists, 0 if the file does not exist, and -1 if unable to check because of directory permissions or some other error that prevents the ability to obtain the information.

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FileOpen
FileOpen(filePath As Character, accessMode As Numeric, shareMode As Numeric, createDisposition As Numeric, attributes As Numeric) As Boolean

This method should only be called on Windows operating systems. It's arguments are similar to the Windows Platform SDK function named CreateFile. For Linux, MAC OS X, and other operating system, use the OpenForRead, OpenForWrite, OpenForReadWrite, and OpenForAppend methods.

Opens a file for reading or writing. The arguments mirror the Windows CreateFile function:

Access Modes:
GENERIC_READ	(0x80000000)
GENERIC_WRITE (0x40000000)

Share Modes:
FILE_SHARE_READ(0x00000001)
FILE_SHARE_WRITE(0x00000002)

Create Dispositions
CREATE_NEW          1
CREATE_ALWAYS       2
OPEN_EXISTING       3
OPEN_ALWAYS         4
TRUNCATE_EXISTING   5

// Attributes:
FILE_ATTRIBUTE_READONLY         0x00000001
FILE_ATTRIBUTE_HIDDEN           0x00000002
FILE_ATTRIBUTE_SYSTEM           0x00000004
FILE_ATTRIBUTE_DIRECTORY        0x00000010
FILE_ATTRIBUTE_ARCHIVE          0x00000020
FILE_ATTRIBUTE_NORMAL           0x00000080
FILE_ATTRIBUTE_TEMPORARY	   0x00000100

Returns .T. for success, .F. for failure.

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FileReadBd
FileReadBd(maxNumBytes As Numeric, binData As CkBinData) As Boolean
Introduced in version 9.5.0.64

Reads bytes from the currently open file. maxNumBytes specifies the maximum number of bytes to read. Appends the bytes to the binData.

Returns .T. for success, .F. for failure.

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FileRename
FileRename(existingFilepath As Character, newFilepath As Character) As Boolean

Renames a file from existingFilepath to newFilepath.

Returns .T. for success, .F. for failure.

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FileSeek
FileSeek(offset As Numeric, origin As Numeric) As Boolean

Sets the file pointer for the currently open file. The offset is an offset in bytes from the origin. The origin can be one of the following:

0 = Offset is from beginning of file.
1 = Offset is from current position of file pointer.
2 = Offset is from the end-of-file (offset may be negative).

Returns .T. for success, .F. for failure.

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FileSize
FileSize(filePath As Character) As Numeric

Returns the size, in bytes, of a file. Returns -1 for failure.

Note: This method returns a signed 32-bit integer, which is not large enough to handle files greater than 2GB in size. To handle larger files, call FileSizeStr instead, or call FileSize64. The FileSize64 method was added in Chilkat v9.5.0.88.

Returns .T. for success, .F. for failure.

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FileSize64
FileSize64(filePath As Character) As Numeric
Introduced in version 9.5.0.88

Returns the size, in bytes, of a file. Returns -1 for failure.

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FileSizeStr
FileSizeStr(filePath As Character) As Character
Introduced in version 9.5.0.80

Returns the size of the file in decimal string format.

Returns .F. on failure

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FileType
FileType(path As Character) As Numeric
Introduced in version 9.5.0.77

Examines the file at path and returns one of the following values:

-1 = Unable to check because of directory permissions or some error preventing the ability to obtain the information.
0 = File does not exist.
1 = Regular file.
2 = Directory.
3 = Symbolic link.
4 = Windows Shortcut.
99 = Something else.

Additional file types may be added in the future as needed.

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FileWriteBd
FileWriteBd(binData As CkBinData, offset As Numeric, numBytes As Numeric) As Boolean
Introduced in version 9.5.0.64

Writes the contents of binData to the currently open file. To specify the entire contents of binData, set both offset and numBytes equal to 0. To write all remaining data starting at offset, then set numBytes equal to 0.

Returns .T. for success, .F. for failure.

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GenBlockId
GenBlockId(index As Numeric, length As Numeric, encoding As Character) As Character
Introduced in version 9.5.0.58

This is purely a utility/convenience method -- initially created to help with block file uploads to Azure Blob storage. It generates a block ID string that is the decimal representation of the index in length chars, and then encoded according to encoding (which can be an encoding such as "base64", "hex", "ascii", etc.) For example, if index = 8, length = 12, and encoding = "base64", then the string "00000012" is returned base64 encoded.

Returns .F. on failure

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GetDirectoryName
GetDirectoryName(path As Character) As Character
Introduced in version 9.5.0.64

Returns the directory information for the specified path string.

GetDirectoryName('C:\MyDir\MySubDir\myfile.ext') returns 'C:\MyDir\MySubDir\'
GetDirectoryName('C:\MyDir\MySubDir') returns 'C:\MyDir\'
GetDirectoryName('C:\MyDir\') returns 'C:\MyDir\'
GetDirectoryName('C:\MyDir') returns 'C:\'
GetDirectoryName('C:\') returns 'C:\'

Returns .F. on failure

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GetExtension
GetExtension(path As Character) As Character
Introduced in version 9.5.0.64

Returns the extension of the specified path string.

GetExtension('C:\mydir.old\myfile.ext') returns '.ext'
GetExtension('C:\mydir.old\') returns ''

Returns .F. on failure

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GetFileName
GetFileName(path As Character) As Character
Introduced in version 9.5.0.64

Returns the file name and extension of the specified path string.

GetFileName('C:\mydir\myfile.ext') returns 'myfile.ext'
GetFileName('C:\mydir\') returns ''

Returns .F. on failure

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GetFileNameWithoutExtension
GetFileNameWithoutExtension(path As Character) As Character
Introduced in version 9.5.0.64

Returns the file name of the specified path string without the extension.

GetFileNameWithoutExtension('C:\mydir\myfile.ext') returns 'myfile'
GetFileNameWithoutExtension('C:\mydir\') returns ''

Returns .F. on failure

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GetFileTime
GetFileTime(path As Character, which As Numeric) As CkDateTime
Introduced in version 9.5.0.71

Gets one of the following date/times for a file:

0: Last-modified
1: Last-access
2: Creation
The "path" argument indicates which time to return. The values can be 0, 1, or 2.

Note: Linux filesystems do not keep a file's creation date/time. In such a case, this method will return the last-modified time.

Returns .F. on failure

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GetLastModified
GetLastModified(path As Character) As CkDateTime
Introduced in version 9.5.0.66

Gets the last-modified date/time for a file. The accuracy of the last-modified data is to the number of seconds.

Returns .F. on failure

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GetNumBlocks
GetNumBlocks(blockSize As Numeric) As Numeric
Introduced in version 9.5.0.58

Returns the number of blocks in the currently open file. The number of bytes per block is specified by blockSize. The number of blocks is the file size divided by the blockSize, plus 1 if the file size is not evenly divisible by blockSize. For example, if the currently open file is 60500 bytes, and if the blockSize is 1000 bytes, then this method returns a count of 61 blocks.

Returns -1 if no file is open. Return 0 if the file is completely empty (0 bytes).

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GetTempFilename
GetTempFilename(dirPath As Character, prefix As Character) As Character

Creates a temporary filepath of the form dirPath\prefix_xxxx.TMP Where "xxxx" are random alpha-numeric chars. The returned filepath is guaranteed to not already exist.

Returns .F. on failure

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OpenForAppend
OpenForAppend(filePath As Character) As Boolean

Opens a file for appending. If filePath did not already exists, it is created. When an existing file is opened with this method, the contents will not be overwritten and the file pointer is positioned at the end of the file.

If the open/create failed, then error information will be available in the FileOpenError and FileOpenErrorMsg properties.

Returns .T. for success, .F. for failure.

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OpenForRead
OpenForRead(filePath As Character) As Boolean

Opens a file for reading. The file may contain any type of data (binary or text) and it must already exist. If the open failed, then error information will be available in the FileOpenError and FileOpenErrorMsg properties.

Returns .T. for success, .F. for failure.

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OpenForReadWrite
OpenForReadWrite(filePath As Character) As Boolean

Opens a file for reading/writing. If filePath did not already exists, it is created. When an existing file is opened with this method, the contents will not be overwritten, but the file pointer is positioned at the beginning of the file.

If the open/create failed, then error information will be available in the FileOpenError and FileOpenErrorMsg properties.

Returns .T. for success, .F. for failure.

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OpenForWrite
OpenForWrite(filePath As Character) As Boolean

Opens a file for writing. If filePath did not already exists, it is created. When an existing file is opened with this method, the contents will be overwritten. (For example, calling OpenForWrite on an existing file and then immediately closing the file will result in an empty file.) If the open/create failed, then error information will be available in the FileOpenError and FileOpenErrorMsg properties.

Returns .T. for success, .F. for failure.

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ReadBinaryToEncoded
ReadBinaryToEncoded(filePath As Character, encoding As Character) As Character

Reads the entire contents of a binary file and returns it as an encoded string (using an encoding such as Base64, Hex, etc.) The encoding may be one of the following strings: base64, hex, qp, or url.

Returns .F. on failure

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ReadBlockBd
ReadBlockBd(blockIndex As Numeric, blockSize As Numeric, bd As CkBinData) As Boolean
Introduced in version 9.5.0.79

Reads the Nth block of a file, where the size of each block is specified by blockSize. The first block is at blockIndex 0. If the block to be read is the last in the file and there is not enough data to fill an entire block, then the partial block is returned. The file data is appended to the contents of bd.

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ReadEntireTextFile
ReadEntireTextFile(filePath As Character, charset As Character) As Character

Reads the entire contents of a text file, interprets the bytes according to the character encoding specified by charset, and returns the text file as a string.

Returns .F. on failure

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ReadNextFragment
ReadNextFragment(startAtBeginning As Boolean, beginMarker As Character, endMarker As Character, charset As Character, sb As CkStringBuilder) As Numeric
Introduced in version 9.5.0.80

Scans the currently open file (opened by calling OpenForRead) for the next chunk of text delimited by beginMarker and endMarker. The matched text, including the beginMarker and endMarker are appended to sb. The bytes of the text file are interpreted according to charset. If startAtBeginning equals .T., then scanning begins at the start of the file. Otherwise scanning begins starting at the byte following the last matched fragment.

The return value of this function is:
0: No match was found.
1: Found the next matching fragment and appended to sb.
-1: Error reading the file.

To support a common need for use with XML files, the beginMarker is "XML tag aware". If the beginMarker is a string such as "", then it will also match "

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ReassembleFile
ReassembleFile(partsDirPath As Character, partPrefix As Character, partExtension As Character, reassembledFilename As Character) As Boolean

Reassembles a file previously split by the SplitFile method.

Returns .T. for success, .F. for failure.

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ReplaceStrings
ReplaceStrings(filePath As Character, charset As Character, existingString As Character, replacementString As Character) As Numeric

Replaces all occurrences of existingString with replacementString in a file. The character encoding, such as utf-8, ansi, etc. is specified by charset.

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SetCurrentDir
SetCurrentDir(dirPath As Character) As Boolean

Sets the current working directory for the calling process to dirPath.

Returns .T. for success, .F. for failure.

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SetFileTimes
SetFileTimes(filePath As Character, createTime As CkDateTime, lastAccessTime As CkDateTime, lastModTime As CkDateTime) As Boolean

Sets the create date/time, the last-access date/time, and the last-modified date/time for a file. For non-Windows filesystems where create times are not implemented, the createTime is ignored.

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SetLastModified
SetLastModified(filePath As Character, lastModified As CkDateTime) As Boolean

Sets the last-modified date/time for a file.

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SplitFile
SplitFile(fileToSplit As Character, partPrefix As Character, partExtension As Character, partSize As Numeric, destDir As Character) As Boolean

Splits a file into chunks. To reassemble a split file, see the ReassembleFile method. Please refer to the example below:

Returns .T. for success, .F. for failure.

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SymlinkCreate
SymlinkCreate(targetPath As Character, linkPath As Character) As Boolean
Introduced in version 9.5.0.77

Creates a symbolic link.

Note: On Windows systems, this is not the same as creating a shortcut. A Windows symbolic link and a Windows shortcut are two different things. Shortcut files are common on Windows, but not symbolic links. Creating a symbolic link requires a special privilege, unless running as administrator. To be able to create symbolic links, your user account or group needs to be listed in secpol.msc → Security Settings → Local Policies → User Rights Assignment → Create symbolic links. However the special setting is not needed when running within the development environment, such as from Visual Studio.

Returns .T. for success, .F. for failure.

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SymlinkTarget
SymlinkTarget(linkPath As Character) As Character
Introduced in version 9.5.0.77

Returns the full pathname of the file at the end of the linkPath. Also handles Windows shortcut files by returning the absolute path of the target.

Returns .F. on failure

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TreeDelete
TreeDelete(path As Character) As Boolean

Deletes an entire directory tree (all files and sub-directories).

Returns .T. for success, .F. for failure.

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Truncate
Truncate() As Boolean
Introduced in version 9.5.0.80

Truncates the currently open file at the current file position.

Returns .T. for success, .F. for failure.

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WriteEntireTextFile
WriteEntireTextFile(filePath As Character, textData As Character, charset As Character, includedPreamble As Boolean) As Boolean

Opens filePath, writes textData using the character encoding specified by charset, and closes the file. If includedPreamble is .T. and the charset is Unicode or utf-8, then the BOM is included at the beginning of the file.

Returns .T. for success, .F. for failure.

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