[Previous][Up][Next] | Reference for unit 'sysutils' (#rtl)

## Unicode and codepage awareness

The many functions that deal with filenames in the sysutils routines have been changed from AnsiString to RawByteString so they do not perform implicit codepage conversions to the ANSI code page. At the same time, overloaded versions that accept a Unicode string have been created.

For routines that access actual OS functions using single-byte string APIS, the strings are converted to ensure that the OS routine receives a string with the correct encoding when using single-byte strings. This encoding is normally the DefaultFileSystemCodePage encoding.

On systems with a Unicode I/O API (2-byte strings), the native API is used, meaning that Unicode strings will be passed on as-is, but single-byte strings will be converted (implicitly) to Unicode.

The following is a minimal list of functions that have been changed and duplicated:

Name | Description
--- | ---
FileCreate | Create a new file and return a handle to it.
FileOpen | Open an existing file and return a file handle
FileExists | Check whether a particular file exists in the file system.
DirectoryExists | Check whether a directory exists in the file system.
FileSetDate | Set the date of a file.
FileGetAttr | Return attributes of a file.
FileSetAttr | Set the attributes of a file.
DeleteFile | Delete a file from the file system.
RenameFile | Rename a file.
FileSearch | Search for a file in a path.
ExeSearch | Search for an executable
FindFirst | Start a file search and return a findhandle
FindNext | Find the next entry in a findhandle.
FindClose | Close a find handle
FileIsReadOnly | Check whether a file is read-only.
GetCurrentDir | Return the current working directory of the application.
SetCurrentDir | Set the current directory of the application.

The following functions do not interact with the OS, but may nevertheless change the codepage of the strings involved in their operation:

Name | Description
--- | ---
ChangeFileExt | Change the extension of a filename.
ExtractFilePath | Extract the path from a filename.
ExtractFileDrive | Extract the drive part from a filename.
ExtractFileName | Extract the filename part from a full path filename.
ExtractFileExt | Return the extension from a filename.
ExtractFileDir | Extract the drive and directory part of a filename.
ExtractShortPathName | Returns a 8.3 path name
ExpandFileName | Expand a relative filename to an absolute filename.
ExpandFileNameCase | Expand a filename entered as case insensitive to the full path as stored on the disk.
ExtractRelativepath | Extract a relative path from a filename, given a base directory.
ExpandUNCFileName | Expand a relative filename to an absolute UNC filename.
IncludeTrailingPathDelimiter | Add trailing directory separator to a pathname, if needed.
IncludeTrailingBackslash | Add trailing directory separator to a pathname, if needed.
ExcludeTrailingBackslash | Strip trailing directory separator from a pathname, if needed.
ExcludeTrailingPathDelimiter | Strip trailing directory separator from a pathname, if needed.
IncludeLeadingPathDelimiter | Prepend a path delimiter if there is not already one.
ExcludeLeadingPathDelimiter | Strip the leading path delimiter of a path
IsPathDelimiter | Is the character at the given position a pathdelimiter ?
DoDirSeparators | Convert known directory separators to the current directory separator.
SetDirSeparators | Set the directory separators to the known directory separators.
GetDirs | Return a list of directory names from a path.
ConcatPaths | Concatenate an array of paths to form a single path
GetEnvironmentVariable | Return the value of an environment variable.

Documentation generated on: May 14 2021