FileAccess Pascal Reference Documentation
FileAccess
Current Version: 11.5.0
Chilkat.FileAccess
Load or save text and binary files, append data, replace file contents,
and work with explicit character encodings when needed.
Copy, rename, delete, compare, split, reassemble, and inspect files using
straightforward file-system utility methods.
Create, remove, check, and work with directories, and use path helpers to
extract filenames, extensions, directory names, and related path parts.
Open files for lower-level reading or writing, seek within files, read
blocks, and process large files without loading everything at once.
Get or set file times, inspect sizes and existence, and use metadata
helpers when coordinating file processing workflows.
Generate temporary filenames, work with symbolic links, scan for byte
fragments, and perform text replacement in files.
For an extended overview, see
FileAccess Class Overview.
Read, write, compare, copy, split, inspect, and manage files and paths.
Chilkat.FileAccess provides general-purpose file-system
utilities for applications that need direct control over files, directories,
paths, timestamps, and low-level file operations. It can read, write, append,
seek, compare, copy, rename, delete, split, reassemble, and inspect files,
and also includes helpers for directory operations, path parsing, symbolic
links, temporary filenames, block-based reading, fragment scanning, text
replacement, and open-file access.
Read and write files
File management
Directories and paths
Open-file operations
Timestamps and metadata
Special file utilities
FileAccess for local file-system tasks that are outside the
scope of a specific protocol class. It is especially useful for preparing
files before upload, saving downloaded data, comparing or splitting files,
reading large files in blocks, manipulating paths, or performing small
filesystem operations without using platform-specific APIs.
Create / Free
uses
Chilkat.FileAccess;
var
obj: TFileAccess;
begin
obj := TFileAccess.Create;
try
if not obj.IsValid then
raise Exception.Create('Failed to create a TFileAccess instance.');
// ... use obj ...
finally
obj.Free;
end;
end;
Allocates the underlying CkFileAccess object and returns a new TFileAccess instance. Simply adding Chilkat.FileAccess to the unit's uses clause is enough to locate and bind to the Chilkat shared library (DLL / .so / .dylib) at runtime — no separate load step is required. Check obj.IsValid after calling Create; it is False if the underlying library could not be found/loaded or the object could not be allocated (for example, when unlicensed).
Every TFileAccess created by calling Create should eventually be released by calling .Free (inherited from TObject). The destructor automatically disposes the underlying CkFileAccess handle. A native (unmanaged) memory leak occurs if the object is never freed.
Properties
CurrentDir
Returns the current working directory of the calling process. Relative file and directory paths are resolved against this process-wide working directory.
FileAccess object. Changing it can therefore affect relative-path behavior elsewhere in the application.DebugLogFilePath
If set to a file path, this property logs the LastErrorText of each Chilkat method or property call to the specified file. This logging helps identify the context and history of Chilkat calls leading up to any crash or hang, aiding in debugging.
Enabling the VerboseLogging property provides more detailed information. This property is mainly used for debugging rare instances where a Chilkat method call causes a hang or crash, which should generally not happen.
Possible causes of hangs include:
- A timeout property set to 0, indicating an infinite timeout.
- A hang occurring within an event callback in the application code.
- An internal bug in the Chilkat code causing the hang.
EndOfFile
Returns True when the currently open file is positioned at end-of-file; otherwise returns False.
OpenForRead, OpenForWrite, OpenForReadWrite, OpenForAppend, or FileOpen.FileOpenError
Provides the detailed open-error code from the most recent call to FileOpen, OpenForRead, OpenForWrite, OpenForReadWrite, or OpenForAppend.
| Code | Meaning |
|---|---|
0 | Success; no open error. |
1 | Access denied. |
2 | File not found. |
3 | General, non-specific open error. |
4 | File already exists. |
5 | The path refers to a directory and the requested access involves writing. |
6 | Too many symbolic links were encountered while resolving the path. |
7 | The process already has the maximum number of files open. |
8 | The pathname is too long. |
9 | The system-wide limit on open files has been reached. |
10 | The pathname refers to a device special file for which no corresponding device exists. |
11 | Insufficient kernel memory was available. |
12 | A file was to be created, but the containing device has no space available. |
13 | A pathname component expected to be a directory is not a directory. |
14 | The regular file is too large to be opened because of an operating-system limitation. |
15 | The path is on a read-only filesystem and write access was requested. |
FileOpenError is useful for programmatic handling; FileOpenErrorMsg provides the corresponding human-readable message.FileOpenErrorMsg
Returns the human-readable message corresponding to FileOpenError for the most recent file-open attempt.
LastErrorHtml
Provides HTML-formatted information about the last called method or property. If a method call fails or behaves unexpectedly, check this property for details. Note that information is available regardless of the method call's success.
topLastErrorText
Provides plain text information about the last called method or property. If a method call fails or behaves unexpectedly, check this property for details. Note that information is available regardless of the method call's success.
LastErrorXml
Provides XML-formatted information about the last called method or property. If a method call fails or behaves unexpectedly, check this property for details. Note that information is available regardless of the method call's success.
topLastMethodSuccess
Indicates the success or failure of the most recent method call: True means success, False means failure. This property remains unchanged by property setters or getters. This method is present to address challenges in checking for null or Nothing returns in certain programming languages. Note: This property does not apply to methods that return integer values or to boolean-returning methods where the boolean does not indicate success or failure.
LockFileOnOpen
Windows only. If True, OpenForAppend, OpenForRead, OpenForReadWrite, and OpenForWrite request exclusive access to the file. Other processes are prevented from opening the file until FileClose releases the handle. The default is False.
OpenFor* method.VerboseLogging
If set to True, then the contents of LastErrorText (or LastErrorXml, or LastErrorHtml) may contain more verbose information. The default value is False. Verbose logging should only be used for debugging. The potentially large quantity of logged information may adversely affect peformance.
Version
Methods
AppendAnsi
Appends text to the currently open file after converting the string to the legacy ANSI character encoding used by Chilkat for the platform.
AppendText or AppendSb when an explicit encoding such as utf-8 is preferred.Returns True for success, False for failure.
topAppendBd
function AppendBd(bd: TChilkatBase): Boolean;
Appends all bytes contained in bd to the currently open file without text conversion.
Returns True for success, False for failure.
topAppendSb
function AppendSb(sb: TChilkatBase;
const charset: string): Boolean;
Appends the text contained in sb to the currently open file using the character encoding specified by charset.
Returns True for success, False for failure.
topAppendText
const charset: string): Boolean;
Appends str to the currently open file after encoding the text with the character set named by charset, such as utf-8 or iso-8859-1.
Returns True for success, False for failure.
topAppendUnicodeBOM
Appends the UTF-16 little-endian byte-order mark to the currently open file. The two bytes written are FF FE.
Returns True for success, False for failure.
topAppendUtf8BOM
Appends the UTF-8 byte-order mark to the currently open file. The three bytes written are EF BB BF.
Returns True for success, False for failure.
topDirAutoCreate
Ensures that the directory portion of filePath exists. Any missing parent directories are created; the final path component is treated as a filename and is not created as a directory.
DirAutoCreate when you have a file path. Use DirEnsureExists when the argument itself is a directory path.Returns True for success, False for failure.
topDirCreate
Creates the directory specified by dirPath. Parent directories must already exist; use DirEnsureExists when missing parent directories should also be created.
Returns True for success, False for failure.
topDirDelete
Deletes the directory specified by dirPath. The directory must be empty; use TreeDelete to recursively delete a directory and its contents.
Returns True for success, False for failure.
topDirEnsureExists
Ensures that the complete directory path dirPath exists, creating missing directories along the path as needed.
Returns True for success, False for failure.
topDirExists
Returns True if dirPath exists as a directory; otherwise returns False.
FileClose
Closes the currently open file and releases its operating-system file handle. Any exclusive lock obtained through LockFileOnOpen is released at this time.
FileContentsEqual
const filePath2: string): Boolean;
Compares filePath1 and filePath2 byte-for-byte and returns True only when their contents are identical. File sizes are compared first; when sizes match, the files are compared incrementally rather than being loaded entirely into memory.
FileCopy
const newFilepath: string;
failIfExists: Boolean): Boolean;
Copies existingFilepath to newFilepath. If failIfExists is True and the destination already exists, the copy fails instead of overwriting it.
Returns True for success, False for failure.
topFileDelete
FileExists
Returns True if filePath exists; otherwise returns False. Use FileExists3 when the application must distinguish "does not exist" from "could not determine because of an error."
FileExists3
Checks whether path exists and returns a three-state result: 1 if it exists, 0 if it does not exist, and -1 if Chilkat could not determine the result because of permissions or another filesystem error.
FileOpen
accessMode: LongWord;
shareMode: LongWord;
createDisposition: LongWord;
attributes: LongWord): Boolean;
Windows-specific low-level open. Opens filePath using arguments modeled after the Win32 CreateFile API. For portable code, prefer OpenForRead, OpenForWrite, OpenForReadWrite, or OpenForAppend.
| Category | Common values |
|---|---|
| Access | GENERIC_READ = 0x80000000, GENERIC_WRITE = 0x40000000 |
| Sharing | FILE_SHARE_READ = 0x1, FILE_SHARE_WRITE = 0x2 |
| Disposition | CREATE_NEW=1, CREATE_ALWAYS=2, OPEN_EXISTING=3, OPEN_ALWAYS=4, TRUNCATE_EXISTING=5 |
FileOpenError and FileOpenErrorMsg for the reason.Returns True for success, False for failure.
topFileReadBd
function FileReadBd(maxNumBytes: Integer;
binData: TChilkatBase): Boolean;
Reads up to maxNumBytes bytes from the current file position and appends the bytes to binData. The file position advances by the number of bytes read.
binData are preserved; newly read bytes are appended.Returns True for success, False for failure.
FileRename
const newFilepath: string): Boolean;
Renames or moves existingFilepath to newFilepath using the local filesystem.
Returns True for success, False for failure.
topFileSeek
origin: Integer): Boolean;
Moves the current file position by offset bytes relative to origin.
0 | Offset from the beginning of the file. |
1 | Offset from the current file position. |
2 | Offset from end-of-file; negative offsets are commonly used. |
Returns True for success, False for failure.
topFileSize
Returns the file size in bytes as a signed 32-bit integer, or -1 on failure.
FileSize64 or FileSizeStr for large files.Returns True for success, False for failure.
topFileSize64
Returns the size of filePath in bytes as a signed 64-bit integer, or -1 on failure.
FileSizeStr
Returns the size of filePath in bytes as a decimal string. This avoids the range limitation of a 32-bit integer return value.
Returns True for success, False for failure.
topFileType
Examines path and classifies the filesystem entry.
-1 | Unable to determine because of permissions or another error. |
0 | Does not exist. |
1 | Regular file. |
2 | Directory. |
3 | Symbolic link. |
4 | Windows shortcut. |
99 | Another filesystem type. |
FileWriteBd
function FileWriteBd(binData: TChilkatBase;
offset: Integer;
numBytes: Integer): Boolean;
Writes bytes from binData to the currently open file. offset selects the starting byte within the BinData; numBytes selects how many bytes to write. Set both to 0 to write the entire BinData, or set numBytes to 0 to write all remaining bytes beginning at offset.
Returns True for success, False for failure.
GenBlockId
length: Integer;
const encoding: string): string;
Generates a fixed-width decimal block identifier from index, padded to length characters, and then encodes those bytes using encoding (for example base64, hex, or ascii). This utility was originally added for block-oriented uploads such as Azure Blob block uploads.
Returns True for success, False for failure.
topGetDirectoryName
Returns the directory portion of path according to Chilkat path-parsing rules.
GetDirectoryName('C:\MyDir\MySubDir\myfile.ext') -> 'C:\MyDir\MySubDir\'
GetDirectoryName('C:\MyDir\MySubDir') -> 'C:\MyDir\'
GetDirectoryName('C:\') -> 'C:\'Returns True for success, False for failure.
GetExtension
Returns the filename extension portion of path, including the leading period. A period appearing only in a directory name is not treated as the file extension.
GetExtension('C:\mydir.old\myfile.ext') -> '.ext'
GetExtension('C:\mydir.old\') -> ''Returns True for success, False for failure.
GetFileName
Returns the final filename component of path, including its extension. If the path ends with a directory separator, the returned filename is empty.
GetFileName('C:\mydir\myfile.ext') -> 'myfile.ext'
GetFileName('C:\mydir\') -> ''Returns True for success, False for failure.
GetFileNameWithoutExtension
Returns the final filename component of path with its extension removed. If path ends with a directory separator, the returned value is empty.
GetFileNameWithoutExtension('C:\mydir\myfile.ext') -> 'myfile'
GetFileNameWithoutExtension('C:\mydir\') -> ''Returns True for success, False for failure.
GetFileTimeStr
which: Integer): string;
Returns one file timestamp as an ISO 8601 UTC string in the form YYYY-MM-DDTHH:MM:SSZ. The which argument selects 0 = last-modified, 1 = last-access, or 2 = creation.
Returns True for success, False for failure.
topGetNumBlocks
Returns how many blockSize-byte blocks are required to cover the currently open file. A partial final block counts as one block. Returns 0 for an empty file and -1 if no file is open.
ceil(fileSize / blockSize) for a non-empty file.GetTempFilename
const prefix: string): string;
Generates a temporary pathname in dirPath using prefix and a random alphanumeric suffix, in the general form prefix_xxxx.TMP. The returned pathname is guaranteed not to already exist at the time it is generated.
Returns True for success, False for failure.
topOpenForAppend
Opens filePath for writing at end-of-file. The file is created if it does not exist. Existing content is preserved, and the initial file position is at the end.
FileOpenError and FileOpenErrorMsg. On Windows, LockFileOnOpen can request exclusive access for this method.Returns True for success, False for failure.
topOpenForRead
Opens an existing filePath for reading. The file may contain text or binary data and must already exist.
FileOpenError and FileOpenErrorMsg. On Windows, LockFileOnOpen can request exclusive access for this method.Returns True for success, False for failure.
OpenForReadWrite
Opens filePath for both reading and writing. The file is created if necessary. Existing content is preserved, and the initial file position is at the beginning.
FileOpenError and FileOpenErrorMsg. On Windows, LockFileOnOpen can request exclusive access for this method.Returns True for success, False for failure.
topOpenForWrite
Opens filePath for writing. The file is created if necessary; if it already exists, it is truncated to zero length when opened.
FileOpenError and FileOpenErrorMsg. On Windows, LockFileOnOpen can request exclusive access for this method.Returns True for success, False for failure.
topReadBinaryToEncoded
const encoding: string): string;
Reads the entire file at filePath as binary data and returns an encoded textual representation. Supported encoding names documented for this method include base64, hex, qp, and url.
Returns True for success, False for failure.
ReadBlockBd
function ReadBlockBd(blockIndex: Integer;
blockSize: Integer;
bd: TChilkatBase): Boolean;
Reads the zero-based block blockIndex from the currently open file, using blockSize bytes per block, and appends the bytes to bd. A partial final block is appended at its actual length.
bd are preserved; the block bytes are appended.ReadEntireTextFile
const charset: string): string;
Reads the entire file at filePath, decodes its bytes using charset, and returns the resulting text.
Returns True for success, False for failure.
topReadNextFragment
function ReadNextFragment(startAtBeginning: Boolean;
const beginMarker: string;
const endMarker: string;
const charset: string;
sb: TChilkatBase): Integer;
Scans the currently open file for the next text fragment beginning with beginMarker and ending with endMarker. The matched fragment, including both markers, is decoded using charset and appended to sb. If startAtBeginning is True, scanning restarts at the beginning of the file; otherwise it continues after the previously matched fragment.
1 | A fragment was found and appended. |
0 | No matching fragment was found. |
-1 | An error occurred while reading. |
ReassembleFile
const partPrefix: string;
const partExtension: string;
const reassembledFilename: string): Boolean;
Reassembles a file previously divided by SplitFile. Parts are read from partsDirPath using the supplied partPrefix and partExtension, and the combined bytes are written to reassembledFilename.
Returns True for success, False for failure.
ReplaceStrings
const charset: string;
const existingString: string;
const replacementString: string): Integer;
Reads the file at filePath as text using charset, replaces occurrences of existingString with replacementString, writes the updated text back to the file, and returns the number of replacements made.
SetCurrentDir
Changes the current working directory of the calling process to dirPath.
Returns True for success, False for failure.
topSetFileTimes
// lastAccessTime is a TCkDateTime object.
// lastModTime is a TCkDateTime object.
function SetFileTimes(const filePath: string;
createTime: TChilkatBase;
lastAccessTime: TChilkatBase;
lastModTime: TChilkatBase): Boolean;
Sets the creation, last-access, and last-modified timestamps for filePath from the supplied CkDateTime objects. On filesystems that do not support a creation/birth time, createTime is ignored.
SetLastModified
function SetLastModified(const filePath: string;
lastModified: TChilkatBase): Boolean;
Sets the last-modified timestamp of filePath from lastModified. The precision actually stored depends on the underlying filesystem.
SplitFile
const partPrefix: string;
const partExtension: string;
partSize: Integer;
const destDir: string): Boolean;
Splits fileToSplit into sequential binary parts of up to partSize bytes and writes them to destDir using partPrefix and partExtension. Use ReassembleFile to reconstruct the original file.
Returns True for success, False for failure.
SymlinkCreate
const linkPath: string): Boolean;
Creates a symbolic link at linkPath that refers to targetPath.
Returns True for success, False for failure.
SymlinkTarget
Returns the resolved target pathname for the symbolic link at linkPath. On Windows, this method also understands Windows shortcut (.lnk) files and returns the absolute target path.
Returns True for success, False for failure.
TreeDelete
Recursively deletes the directory tree rooted at path, including contained files and subdirectories.
path identifies the intended tree before calling it.Returns True for success, False for failure.
topTruncate
Truncates the currently open file at the current file position. Bytes at and after that position are removed, making the current position the new end-of-file.
Truncate.Returns True for success, False for failure.
topWriteEntireTextFile
const textData: string;
const charset: string;
includedPreamble: Boolean): Boolean;
Creates or opens filePath, encodes textData using charset, writes the resulting bytes, and closes the file. Existing file content is replaced. If includePreamble is True, an appropriate preamble/BOM is included for encodings such as UTF-8 or UTF-16.
Returns True for success, False for failure.