Read

   

Declaration:

Procedure Read ([Var F : Any file type], V1 [, V2, ... , Vn]) ;

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 or String.

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 {$i} compiler switch.

See also:

Readln, Blockread, Write, Blockwrite

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.