🚀 go-pugleaf

In article <4f67kg$11g@cortex.dialin.rrze.uni-erlangen.de>,
Markus Kuhn <mskuhn@cip.informatik.uni-erlangen.de> wrote:
> Why isn't there a standard way of allowing an ISO C program to switch
> the standard input and output into binary transparent mode (as with
> the "b" flag in fopen()/freopen() for normal files)?
>
> Has this just been forgotten or is there a good technical reason?

On some implementations, this decision has to be made at the time you
open the file and can't be changed. For example, on OS/360 and its
successors, text files might be VB80, while binary files will be U508,
or whatever. The former is stored as:

    <4 byte value N1> <N1 bytes of text forming a line>
    <4 byte value N2> <N1 bytes of text forming a line>
    <4 byte value N3> <N1 bytes of text forming a line>
    ...

(note that there are no newline characters) and the latter as

    <4 byte value N1> <N1 bytes of data> <508-N1 bytes ignored>
    <4 byte value N2> <N1 bytes of data> <508-N1 bytes ignored>
    <4 byte value N3> <N1 bytes of data> <508-N1 bytes ignored>
    ...

(data is read and written in 512 byte units). How do you switch these ?

-- 
Clive D.W. Feather                       | If you lie to the compiler,
cdwf@cityscape.co.uk   (work, preferred) | it will get its revenge.
clive@stdc.demon.co.uk (home)            |   - Henry Spencer