Read

Read from a text file into variable

Declaration

Source position: line 0

Description

Read reads one or more values from a file F, and stores the result in V1, V2, etc.; If no file F is specified, then standard input is read. If F is of type Text, then the variables V1, V2 etc. must be of type Char, Integer, Real, String or PChar. If F is a typed file, then each of the variables must be of the type specified in the declaration of F. Untyped files are not allowed as an argument.

Errors

If no data is available, a run-time error is generated. This behavior can be controlled with the \var{\{\$i\}} compiler switch.

See also

Example

Program Example50;

{ Program to demonstrate the Read(Ln) function. }

Var S : String;
    C : Char;
    F : File of char;

begin
  Assign (F,'ex50.pp');
  Reset (F);
  C:='A';
  Writeln ('The characters before the first space in ex50.pp are : ');
  While not Eof(f) and (C<>' ') do
    Begin
    Read (F,C);
    Write (C);
    end;
 Writeln;
 Close (F);
 Writeln ('Type some words. An empty line ends the program.');
 repeat
   Readln (S);
 until S='';
end.

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