Delphi files for read and write operations

delphi file operations

Take file name 
ExtractFileName (FileName); 
get file extensions: 
ExtractFileExt (filename); 
get file name without an extension: 

Method a: 

Function ExtractFileNameNoExt (FileString: String): String; 
Var 
  FileWithExtString: String; 
  FileExtString: String; 
  LenExt : Integer; 
  LenNameWithExt: Integer; 
the Begin 
  FileWithExtString: = ExtractFileName (FileString); 
  LenNameWithExt: = the Length (FileWithExtString); FileExtString: = ExtractFileExt (FileString); LenExt: = the Length (FileExtString); 
  the If LenExt = 0 the Then 
     the Begin 
       the Result: =FileWithExtString; 
     End 
     Else 
      the Begin 
       the Result: = the Copy (FileWithExtString, . 1 , (LenNameWithExt- LenExt)); 
      End; 
 End; 
Method two: 

ChangeFileExt (ExtractFileName (Application.ExeName), '' )

 ---------- -------------------------------------------------- -------------------------------------------------- -------------------------------------------------- ------------------------- // Delphi get file path where 
ExtractFileDrive: return to drive the full file name, such as "C:" 
ExtractFilePath: return the full path of the file name, the last with a " /", such as "C: / the Test / " 
ExtractFileDir: return the full path of the file name, without the last " /", such as "C: /




 the Test"
ExtractFileName: Returns the full file name of the file name (extension), as "mytest.doc" 
ExtractFileExt return to full file name extension in the file name (band), such as ".doc" 

ExtractRelativePath: relative path is returned, as defined below : 
function ExtractRelativePath ( const BaseName, DestName: String ): String ; 
under test, such as using: 
SysUtils.ExtractRelativePath ( ' C: / test ' , ' C: / the test / TestRelativePath ' ): returns TestRelativePath 
SysUtils.ExtractRelativePath ( ' C: / the Test / TestRelativePath ' , ' C: / Test ' ): returns ' ../TestRelativePath ' 
the SysUtils.ExtractRelativePath(' C: / the Test / TestRelativePath / ' , ' C: / Test ' ): Returns ' ../../TestRelativePath ' 
ExtractShortPathName: Returns short filenames, i.e., 8 + 3 , eight long file name, extension 3 number, in order to maintain compatibility exists DOS system 
 
to obtain the file name without a path, can be used: 
ChangeFileExt (TIdAttachment (Msg.MessageParts.Items [intIndex]) filename,. '' ); function to get rid of the extension. ? At present it seems that one way, and who has a better way, please inform 
 
 
Attached elsewhere information: 
 
1 , the file name functions 
  for file names can function name of the file, where the subdirectories, and the drive name and other extensions operating. The following table lists these functions and their functions. 
Function Description 
ExpandFileName () returns the file full path (including the drive, path) 
ExtractFileExt () to extract the extension from the file name 
ExtractFileName () extracted without a path from the file name in the file name 
ExtractFilePath () extracts the path name from the file name
ExtractFileDir () extracts directory name from the file name 
ExtractFileDrive () extracted from the file name drive name 
ChangeFileExt () to change the file extension 
ExpandUNCFileName () returns a file containing the network drives full path 
ExtractRelativePath () to extract the relative path information from the file name 
ExtractShortPathName () the file name for the converted 8-DOS- 3 format 
MatchesMask () to check whether a file with the specified file name format matching 
ExtractFilePath (fileName: String) 
this function returns the path name, which always end character " / " 
ExtractFileDir (fileName : String) 
this function also returns the path name, but does not include the end of the character " / " unless the return path is the root directory. 
  These functions put the following work introduced one by one: 
⑴ExpandFileName () 
  Prototype: extern PACKAGE of the AnsiString __fastcall ExpandFileName ( const the AnsiString FileName); 
  Function: Return the full path to the file (including drive, path) 
  Parameters: FileName: file name to be processed
  Example: ShowMessage (ExpandFileName (the Application -> ExeName)); // display your file name, such as C: /MyBCB/Sample1.EXE 
⑵ExtractFileExt () 
  prototype: extern PACKAGE AnsiString __fastcall ExtractFileExt ( const AnsiString FileName); 
  Function: extracting the file name extension 
  parameters: fileName: file name (full path) to be treated 
  Example: the ShowMessage (ExtractFileExt (the Application -> ExeName)); // displays ".exe" 
⑶ExtractFileName () 
  prototype: extern PACKAGE AnsiString __fastcall ExtractFileName ( const the AnsiString fileName); 
  function: free path extracted from the file name of the file name 
  parameters: fileName: file name to be processed 
  Example: the ShowMessage (ExtractFileExt ( "C: // the Winnt SOL.EXE //")); // show "SOL.EXE" 
⑷ExtractFilePath ()
  Prototype: extern PACKAGE of the AnsiString __fastcall ExtractFilePath ( const  AnsiString FileName);
  functions: extracting from the file name in the path name of 
  the file name to be addressed: Parameters: FileName 
  Example: the ShowMessage (ExtractFilePath ( "the Winnt // SOL.EXE")); // Display "Winnt / " 
⑸ExtractFileDir () 
  prototype: extern PACKAGE of the AnsiString __fastcall ExtractFileDir ( const the AnsiString fileName); 
  function: extract directory name from the file name (and the functions of different excluding the last" / ") 
  parameters: fileName: to process the file name 
  Example: the ShowMessage (ExtractFileDir ( "the Winnt // SOL.EXE")); // displays "Winnt", and note the difference functions 
⑹ExtractFileDrive () 
  prototype: extern PACKAGE of the AnsiString __fastcall ExtractFileDrive ( const the AnsiString FileName); 
  function: the file name to extract the drive name 
  parameters: file name to be processed: fileName 
  Example: the ShowMessage (ExtractFileDrive ( "c: // Winnt // SOL.EXE ")); // display the" c: "
⑺ChangeFileExt () 
  prototype: extern PACKAGE System :: AnsiString __fastcall ChangeFileExt ( const System :: AnsiString FileName, const System :: AnsiString Extension); 
  function: change the file name extension is not on the real file renamed, just the file name this string processing 
  parameters: fileName: name of the file to be renamed, extension: new extension 
  Example: the ShowMessage (ChangeFileExt ( "C: // the Winnt SOL.EXE //",. "OOO")); // display "C: /winnt/SOL.OOO" 
⑻ExpandUNCFileName () 
  prototype: extern PACKAGE of the AnsiString __fastcall ExpandUNCFileName ( const the AnsiString fileName); 
  function: returns the file containing the full path of the network drive, format: // machine / share / file
  Parameters: FileName: file name to be processed 
  Example: the ShowMessage (ExpandUNCFileName ( "F: // the Winnt SOL.EXE //")); / * if F: is mapped network drives, displays "
⑼ExtractRelativePath () 
  Prototype: extern PACKAGE of the AnsiString __fastcall ExtractRelativePath ( const the AnsiString BaseName, const the AnsiString DestName); 
  Function: relative path information extracted from the file name, such as ".. / sss / ss.asd" this form 
  parameters: BaseName: reference file name; DestName: destination file name 
  Example: ShowMessage (ExtractRelativePath ( "D: // Source // 1.123 // c", "D: //Source//Asm//dz.asm")); / * display " ../asm/dz.asm"*/ 
⑽ExtractShortPathName () 
  prototype: extern PACKAGE of the AnsiString __fastcall ExtractShortPathName ( const the AnsiString fileName); 
  function: 8 converts the file name, to the DOS 3 format 
  parameters: fileName: name of file to be processed 
  Example : ShowMessage (ExtractShortPathName ( "E: // Program Files // // 4dmain.exe Dual Wheel Mouse")); / * Display "E: / Progra ~ 1 / dualwh . 1 ~ / 4dmain.exe "* / 
⑾MatchesMask () 
  prototype: extern PACKAGE of BOOL __fastcall MatchesMask ( const the AnsiString filename, const the AnsiString Mask); 
  function: check whether the file specified file name format matching 
  parameters: fileName: name of the file to be treated ; Mask: filename format, supports wildcards 
  Example: ShowMessage (MatchesMask ( "Lxf.exe", " .?? the X-*)); // display" true "

 

 

 

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Origin www.cnblogs.com/crrc/p/10943522.html