Read and Write

The file read function has two parameters

  read( unit=unit-no, fmt=format-label )   [ list of arguments ]

Each parameter can be replaced by a , with the meaning ``default unit'' or ``default format''. We will talk later about formats.

The call

  read(5,*) R, V

reads two reals from unit number 5 in default format. Unit is predefined, and is the standard input (keyboard, unless redirected). Thus, an equivalent formulation is

  read(*,*) R, V

The file write function is very similar,

  write( unit\_no, format label )  [ list of arguments ]

Each parameter can be replaced by a (defaults). The call

  write(6,*) R, V

writes two reals onto unit number 6 in default format. Unit is predefined, and is the standard output (monitor, unless redirected). Thus, an equivalent formulation is

  write(*,*) R, V

The list of arguments must be of standard intrinsic types (unless explicit format is used). Each READ statement reads the arguments from a new line; non-advancing READ is possible, but we need to use formats.