sysutils.pas

这是不可多得的源代码

function StrToBoolDef(const S: string; const Default: Boolean): Boolean;
function TryStrToBool(const S: string; out Value: Boolean): Boolean;

function BoolToStr(B: Boolean; UseBoolStrs: Boolean = False): string;

{ LoadStr loads the string resource given by Ident from the application's
  executable file or associated resource module. If the string resource
  does not exist, LoadStr returns an empty string. }

function LoadStr(Ident: Integer): string;

{ FmtLoadStr loads the string resource given by Ident from the application's
  executable file or associated resource module, and uses it as the format
  string in a call to the Format function with the given arguments. }

function FmtLoadStr(Ident: Integer; const Args: array of const): string;

{ File management routines }

{ FileOpen opens the specified file using the specified access mode. The
  access mode value is constructed by OR-ing one of the fmOpenXXXX constants
  with one of the fmShareXXXX constants. If the return value is positive,
  the function was successful and the value is the file handle of the opened
  file. A return value of -1 indicates that an error occurred. }

function FileOpen(const FileName: string; Mode: LongWord): Integer;

{ FileCreate creates a new file by the specified name. If the return value
  is positive, the function was successful and the value is the file handle
  of the new file. A return value of -1 indicates that an error occurred.
  On Linux, this calls FileCreate(FileName, DEFFILEMODE) to create
  the file with read and write access for the current user only.  }

function FileCreate(const FileName: string): Integer; overload;

{ This second version of FileCreate lets you specify the access rights to put on the newly
  created file.  The access rights parameter is ignored on Win32 }

function FileCreate(const FileName: string; Rights: Integer): Integer; overload;

{ FileRead reads Count bytes from the file given by Handle into the buffer
  specified by Buffer. The return value is the number of bytes actually
  read; it is less than Count if the end of the file was reached. The return
  value is -1 if an error occurred. }

function FileRead(Handle: Integer; var Buffer; Count: LongWord): Integer;

{ FileWrite writes Count bytes to the file given by Handle from the buffer
  specified by Buffer. The return value is the number of bytes actually
  written, or -1 if an error occurred. }

function FileWrite(Handle: Integer; const Buffer; Count: LongWord): Integer;

{ FileSeek changes the current position of the file given by Handle to be
  Offset bytes relative to the point given by Origin. Origin = 0 means that
  Offset is relative to the beginning of the file, Origin = 1 means that
  Offset is relative to the current position, and Origin = 2 means that
  Offset is relative to the end of the file. The return value is the new
  current position, relative to the beginning of the file, or -1 if an error
  occurred. }

function FileSeek(Handle, Offset, Origin: Integer): Integer; overload;
function FileSeek(Handle: Integer; const Offset: Int64; Origin: Integer): Int64; overload;

{ FileClose closes the specified file. }

procedure FileClose(Handle: Integer);

{ FileAge returns the date-and-time stamp of the specified file. The return
  value can be converted to a TDateTime value using the FileDateToDateTime
  function. The return value is -1 if the file does not exist. }

function FileAge(const FileName: string): Integer;

{ FileExists returns a boolean value that indicates whether the specified
  file exists. }

function FileExists(const FileName: string): Boolean;

{ DirectoryExists returns a boolean value that indicates whether the
  specified directory exists (and is actually a directory) }

function DirectoryExists(const Directory: string): Boolean;

{ ForceDirectories ensures that all the directories in a specific path exist.
  Any portion that does not already exist will be created.  Function result
  indicates success of the operation.  The function can fail if the current
  user does not have sufficient file access rights to create directories in
  the given path.  }

function ForceDirectories(Dir: string): Boolean;

{ FindFirst searches the directory given by Path for the first entry that
  matches the filename given by Path and the attributes given by Attr. The
  result is returned in the search record given by SearchRec. The return
  value is zero if the function was successful. Otherwise the return value
  is a system error code. After calling FindFirst, always call FindClose.
  FindFirst is typically used with FindNext and FindClose as follows:

    Result := FindFirst(Path, Attr, SearchRec);
    while Result = 0 do
    begin
      ProcessSearchRec(SearchRec);
      Result := FindNext(SearchRec);
    end;
    FindClose(SearchRec);

  where ProcessSearchRec represents user-defined code that processes the
  information in a search record. }

function FindFirst(const Path: string; Attr: Integer;
  var F: TSearchRec): Integer;

{ FindNext returs the next entry that matches the name and attributes
  specified in a previous call to FindFirst. The search record must be one
  that was passed to FindFirst. The return value is zero if the function was
  successful. Otherwise the return value is a system error code. }

function FindNext(var F: TSearchRec): Integer;

{ FindClose terminates a FindFirst/FindNext sequence and frees memory and system
  resources allocated by FindFirst.
  Every FindFirst/FindNext must end with a call to FindClose. }

procedure FindClose(var F: TSearchRec);

{ FileGetDate returns the OS date-and-time stamp of the file given by
  Handle. The return value is -1 if the handle is invalid. The
  FileDateToDateTime function can be used to convert the returned value to
  a TDateTime value. }

function FileGetDate(Handle: Integer): Integer;

{ FileSetDate sets the OS date-and-time stamp of the file given by FileName
  to the value given by Age. The DateTimeToFileDate function can be used to
  convert a TDateTime value to an OS date-and-time stamp. The return value
  is zero if the function was successful. Otherwise the return value is a
  system error code.        }

function FileSetDate(const FileName: string; Age: Integer): Integer; overload;

{$IFDEF MSWINDOWS}
{  FileSetDate by handle is not available on Unix platforms because there
  is no standard way to set a file's modification time using only a file
  handle, and no standard way to obtain the file name of an open
  file handle.  }

function FileSetDate(Handle: Integer; Age: Integer): Integer; overload; platform;

{ FileGetAttr returns the file attributes of the file given by FileName. The
  attributes can be examined by AND-ing with the faXXXX constants defined
  above. A return value of -1 indicates that an error occurred. }

function FileGetAttr(const FileName: string): Integer; platform;

{ FileSetAttr sets the file attributes of the file given by FileName to the
  value given by Attr. The attribute value is formed by OR-ing the
  appropriate faXXXX constants. The return value is zero if the function was
  successful. Otherwise the return value is a system error code. }

function FileSetAttr(const FileName: string; Attr: Integer): Integer; platform;
{$ENDIF}

{ FileIsReadOnly tests whether a given file is read-only for the current
  process and effective user id.  If the file does not exist, the
  function returns False.  (Check FileExists before calling FileIsReadOnly)
  This function is platform portable. }

function FileIsReadOnly(const FileName: string): Boolean;

{ FileSetReadOnly sets the read only state of a file.  The file must
  exist and the current effective user id must be the owner of the file.
  On Unix systems, FileSetReadOnly attempts to set or remove
  all three (user, group, and other) write permissions on the file.
  If you want to grant partial permissions (writeable for owner but not
  for others), use platform specific functions such as chmod.
  The function returns True if the file was successfully modified,
  False if there was an error.  This function is platform portable.  }

function FileSetReadOnly(const FileName: string; ReadOnly: Boolean): Boolean;

{ DeleteFile deletes the file given by FileName. The return value is True if
  the file was successfully deleted, or False if an error occurred. }

function DeleteFile(const FileName: string): Boolean;

{ RenameFile renames the file given by OldName to the name given by NewName.
  The return value is True if the file was successfully renamed, or False if
  an error occurred. }

function RenameFile(const OldName, NewName: string): Boolean;

{ ChangeFileExt changes the extension of a filename. FileName specifies a
  filename with or without an extension, and Extension specifies the new
  extension for the filename. The new extension can be a an empty string or
  a period followed by up to three characters. }

function ChangeFileExt(const FileName, Extension: string): string;

{ ExtractFilePath extracts the drive and directory parts of the given
  filename. The resulting string is the leftmost characters of FileName,
  up to and including the colon or backslash that separates the path
  information from the name and extension. The resulting string is empty
  if FileName contains no drive and directory parts. }

function ExtractFilePath(const FileName: string): string;

{ ExtractFileDir extracts the drive and directory parts of the given
  filename. The resulting string is a directory name suitable for passing
  to SetCurrentDir, CreateDir, etc. The resulting string is empty if
  FileName contains no drive and directory parts. }

function ExtractFileDir(const FileName: string): string;

{ ExtractFileDrive extracts the drive part of the given filename.  For
  filenames with drive letters, the resulting string is '<drive>:'.
  For filenames with a UNC path, the resulting string is in the form
  '\\<servername>\<sharename>'.  If the given path contains neither
  style of filename, the result is an empty string. }

function ExtractFileDrive(const FileName: string): string;

{ ExtractFileName extracts the name and extension parts of the given
  filename. The resulting string is the leftmost characters of FileName,
  starting with the first character after the colon or backslash that
  separates the path information from the name and extension. The resulting
  string is equal to FileName if FileName contains no drive and directory
  parts. }

function ExtractFileName(const FileName: string): string;

{ ExtractFileExt extracts the extension part of the given filename. The
  resulting string includes the period character that separates the name
  and extension parts. The resulting string is empty if the given filename
  has no extension. }

function ExtractFileExt(const FileName: string): string;

{ ExpandFileName expands the given filename to a fully qualified filename.
  The resulting string consists of a drive letter, a colon, a root relative
  directory path, and a filename. Embedded '.' and '..' directory references
  are removed. }

function ExpandFileName(const FileName: string): string;

{ ExpandFilenameCase returns a fully qualified filename like ExpandFilename,
  but performs a case-insensitive filename search looking for a close match
  in the actual file system, differing only in uppercase versus lowercase of
  the letters.  This is useful to convert lazy user input into useable file
  names, or to convert filename data created on a case-insensitive file
  system (Win32) to something useable on a case-sensitive file system (Linux).

  The MatchFound out parameter indicates what kind of match was found in the
  file system, and what the function result is based upon:

  ( in order of increasing difficulty or complexity )
  mkExactMatch:  Case-sensitive match.  Result := ExpandFileName(FileName).
  mkSingleMatch: Exactly one file in the given directory path matches the
        given filename on a case-insensitive basis.
        Result := ExpandFileName(FileName as found in file system).
  mkAmbiguous: More than one file in the given directory path matches the
        given filename case-insensitively.
        In many cases, this should be considered an error.
        Result := ExpandFileName(First matching filename found).
  mkNone:  File not found at all.  Result := ExpandFileName(FileName).

  Note that because this function has to search the file system it may be
  much slower than ExpandFileName, particularly when the given filename is
  ambiguous or does not exist.  Use ExpandFilenameCase only when you have
  a filename of dubious orgin - such as from user input - and you want
  to make a best guess before failing.  }

type
  TFilenameCaseMatch = (mkNone, mkExactMatch, mkSingleMatch, mkAmbiguous);

function ExpandFileNameCase(const FileName: string;
  out MatchFound: TFilenameCaseMatch): string;

{ ExpandUNCFileName expands the given filename to a fully qualified filename.
  This function is the same as ExpandFileName except that it will return the
  drive portion of the filename in the format '\\<servername>\<sharename> if
  that drive is actually a network resource instead of a local resource.
  Like ExpandFileName, embedded '.' and '..' directory references are
  removed. }

function ExpandUNCFileName(const FileName: string): string;

{ ExtractRelativePath will return a file path name relative to the given
  BaseName.  It strips the common path dirs and adds '..\' on Windows,
  and '../' on Linux for each level up from the BaseName path. }

function ExtractRelativePath(const BaseName, DestName: string): string;

{$IFDEF MSWINDOWS}
{ ExtractShortPathName will convert the given filename to the short form
  by calling the GetShortPathName API.  Will return an empty string if
  the file or directory specified does not exist }

function ExtractShortPathName(const FileName: string): string;
{$ENDIF}

{ FileSearch searches for the file given by Name in the list of directories
  given by DirList. The directory paths in DirList must be separated by
  PathSep chars. The search always starts with the current directory of the
  current drive. The returned value is a concatenation of one of the
  directory paths and the filename, or an empty string if the file could not
  be located. }

function FileSearch(const Name, DirList: string): string;

{$IFDEF MSWINDOWS}
{ DiskFree returns the number of free bytes on the specified drive number,
  where 0 = Current, 1 = A, 2 = B, etc. DiskFree returns -1 if the drive
  number is invalid. }

function DiskFree(Drive: Byte): Int64;

{ DiskSize returns the size in bytes of the specified drive number, where
  0 = Current, 1 = A, 2 = B, etc. DiskSize returns -1 if the drive number
  is invalid. }

function DiskSize(Drive: Byte): Int64;
{$ENDIF}

{ FileDateToDateTime converts an OS date-and-time value to a TDateTime
  value. The FileAge, FileGetDate, and FileSetDate routines operate on OS
  date-and-time values, and the Time field of a TSearchRec used by the
  FindFirst and FindNext functions contains an OS date-and-time value. }