Important Notice

The pages on this site contain documentation for very old MS-DOS software, purely for historical purposes. If you're looking for up-to-date documentation, particularly for programming, you should not rely on the information found here, as it will be woefully out of date.

  ◄Summary► ◄Details► ◄Example►                                   ◄Back►
 
  Arguments
 
    file_variable    Optional; text or typed file (default is the
                     standard file Input)
 
    <expression>     One required, others optional; for text files, an
                     expression of any simple type; for typed files, a
                     variable of the same type as the component type of
                     the file
 
    <format>         Optional; depends on type of expression (applies
                     only to text files)
 
  Description
 
    The Write procedure writes one or more values to a disk file or
    device. The file must be open. If no output file is specified,
    Write writes to the standard text file Output.
 
    For a text file, the current position is always at the end, and
    Write appends to the file. Write does not end output to a text
    file with an end-of-line character. Use Writeln to write lines of
    text.
 
    For a typed file, if the current position is at end-of-file, Write
    appends to the file. Otherwise, Write overwrites existing data and
    advances the current file position to the next component. The file
    must be opened for output by using the Append or Rewrite procedures.
 
    Standard output goes to the screen unless redirected to a file by
    the DOS redirection operator, (>). Use the Assign procedure to
    reenable redirection when using the Crt unit.
 
    The format argument is optional and varies with the expression
    type:
 
      1. For character, Boolean, or string output, the format is
 
         ■ <expression> [ : width ]
 
         The width argument is a positive integer expression giving a
         minimum field width. The characters are right justified within
         the field if they fit. If they do not fit or if width is
         omitted, the characters take as much space as needed.
 
         For Boolean expressions, the output is a string of text,
         either 'TRUE' or 'FALSE'.
 
      2. For numeric output, the format is
 
         ■ <expression> [ : width [ : places ] ]
 
         The width and places arguments are positive integer
         expressions that control the conversion format. The
         expression is either an integer or a real type. The
         formatting specification is the same as that passed to
         the Str procedure.
 
         The width argument gives the minimum field width. The number
         is right justified within the field if it fits. For an
         integer, if the number does not fit or if width is omitted,
         the number takes as much space as needed. For a real number,
         if width is less than 8, the value is ignored and a field
         width of 8 is used. If width is omitted, a width of 23 is
         assumed. The field width includes the decimal point and any
         places after the decimal. A negative width is ignored.
 
         The places argument gives the number of places to the right of
         the decimal. This parameter applies only to real arguments
         when width is specified. If places is greater than 18 or is
         negative, 18 decimal places are used. Omit places or give a
         negative value to write in scientific (engineering) notation.
         Specify 0 places to round a real to the nearest whole number.
 
    The output string for an integer has the form:
 
       [-] <decimal digits>
 
    The output string for a real number has the form:
 
       [-] <digits> [.<digits>] [ {E│e} [+│-] <digits> ]
 
    Numeric output in hexadecimal format is not possible.
 
    If file_variable is not associated with a file or if the file is
    not open when Write is called, an I/O error occurs.
 
    If Write is called for a text file opened for reading with Reset,
    an I/O error occurs.
 
    To prevent a program from halting with a run-time error when an I/O
    error occurs, turn off I/O checking with {$I-} and check the return
    value of the IOResult function.