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Categories / Delphi / Procedures

 

Assignfile - assigns a file handle to a binary or text file system unit

1 procedure AssignFile ( var FileHandle : TextFile; const FileName : string ) ; 2 procedure AssignFile ( var FileHandle : File; const FileName : string ) ; Description The AssignFile procedure assigns a value to FileHandle for a FileName in preparation for reading or writing to that file. Version 1 Takes a text file variable type as the handle. The file is treated as a textfile when opened. If the file name is an empty string, then file access is made to the console standard input and output streams. Version 2 Takes a binary file variable type as the handle. The file is treated as a binary file. In both cases, when the file is opened by Append, Reset or ReWrite, it is assumed to be in the current directory. Notes The FileHandle must no be confused with the file handle used for the low level file handling routines such as FileOpen and FileRead. Related commands Append Open a text file to allow appending of text to the end AssignPrn Treats the printer as a text file - an easy way of printing text File Defines a typed or untyped file Reset Open a text file for reading, or binary file for read/write ReWrite Open a text or binary file for write access TextFile Declares a file type for storing lines of text Example code : Write to a text file, and then read back its contents var myFile : TextFile; text : string; begin // Try to open the Test.txt file for writing to AssignFile(myFile, 'Test.txt'); ReWrite(myFile); // Write a couple of well known words to this file WriteLn(myFile, 'Hello'); WriteLn(myFile, 'World'); // Close the file CloseFile(myFile); // Reopen the file for reading Reset(myFile); // Display the file contents while not Eof(myFile) do begin ReadLn(myFile, text); ShowMessage(text); end; // Close the file for the last time CloseFile(myFile); end; Show full unit code Hello World