Re: Feed control

On 4/3/2024 8:43 AM, db wrote:

When I learned Fortran many years ago, the first
character in a line to be printed (or later,
displayed) controlled line or page feed. A blank
produced a new line, a "1" a new page. We used these
to control what happened.
 These days, this doesn't seem to be the case, so
in a sense, Fortran is no longer backward
compatible in this one sense. Or is it?

Fortran character control in formatted I/O is a "deleted feature" and is no longer part of the standard. As is typical for deleted features, it is still supported by many compilers, though you may have to ask for it. It also perseveres in such things as list-directed output specifying that the output record starts with a blank.
Fortran carriage control is an artifact of the line printer era - I remember punching carriage control tapes in the 70s. In addition, many of today's output devices and environments don't support it.
By definition, deleted features mean that programs that conform to a previous standard no longer conform to the current one. In nearly all cases, these are features that are poor practice and are replaced by better ones, though compilers almost always continue to support them.
--
Steve Lionel
ISO/IEC JTC1/SC22/WG5 (Fortran) Convenor
Retired Intel Fortran developer/support
Email: firstname at firstnamelastname dot com
Twitter: @DoctorFortran
LinkedIn: https://www.linkedin.com/in/stevelionel
Blog: https://stevelionel.com/drfortran
WG5: https://wg5-fortran.org