Delphi in a Nutshell

Name

TextFile Type

Syntax

type TextFile;

Description

The TextFile type represents a text file. A text file is different from a binary file in that a text file contains lines of text, where the size of each line can vary. Unlike standard Pascal, the TextFile type is unrelated to File of Char.

The actual encoding of a line ending is not relevant in a Delphi program. The ReadLn and WriteLn procedures and the Eoln and SeekEoln functions automatically handle line endings. A text file ends at the end of the file or at the first occurrence of the #26 character (Ctrl-Z).

Tips and Tricks

• By default, text files are buffered with a 128-byte buffer. You can choose a different size buffer by calling SetTextBuf.

• The TextFile type is equivalent to the following record. The SysUtils unit has a declaration of this type, or you can copy the declaration to your own unit.

type PTextBuf = ^TTextBuf; TTextBuf = array[0..127] of Char; TTextRec = packed record Handle: Integer; Mode: Integer; // fmInput or fmOutput BufSize: Cardinal; // Size of Buffer. BufPos: Cardinal; // Current position in Buffer. BufEnd: Cardinal; // Last position of data in Buffer. BufPtr: PChar; // Pointer to the start of the data in Buffer. OpenFunc: Pointer; // Pointers to functions that take a InOutFunc: Pointer; // var TextFile argument and return an FlushFunc: Pointer; // integer result: zero for success and an CloseFunc: Pointer; // error code for an error. UserData: array[1..32] of Byte; // For your use. Name: array[0..259] of Char; ...