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fortrangfortranflushcarriage-return

How to carriage return and flush in Fortran?

I've always wondered about whether or not you can carriage return and flush a write statement in Fortran. In Python/C++ you can '/r' then flush the stream.

How can I do this in Fortran?

Solution

  • A carriage-return is inserted by default at the end of a write statement, or explicitly using the ADVANCE specifier:

    write(unit , '(A)') 'Hello World'
write(unit , '(A)' , ADVANCE = 'YES') 'Hello World'
write(unit , '(A)' , ADVANCE = 'YES') '-'

    The result of the preceding three statements is:

    Hello World
Hello World
-

    Alternatively, the carriage-return may be suppressed by specifying ADVANCE='NO':

    write(unit , '(A)' , ADVANCE = 'NO') 'Hello World'
write(unit , '(A)' , ADVANCE = 'NO') 'Hello World'
write(unit , '(A)' , ADVANCE = 'NO') '-'

    Which yields:

    Hello WorldHello World-

    To flush in Fortran90, close the file and reopen. Specific compilers and/or newer versions of the Fortran standard offer FLUSH as an intrinsic, but closing the file will always have the effect of flushing regardless of your Fortran version.