Re: controlling stdio buffering

[Paul Eggert]

Pádraig Brady <address@hidden> writes:

> Paul Eggert wrote:
>>If this is merely for debugging, can't you write a wrapper that forces
>>line buffering for a program?  The wrapper could substitute your own C
>>library functions via LD_PRELOAD, or could run the program inside a
>>pseudotty a la 'expect'.

> No I was thinking of a more simple general solution,
> rather than a once off complicated hack.

But the solution I proposed is general, and would not be a once-off hack.
It could be packaged up into a program like 'nohup' that could invoke
any other program.  Such a program (let's call it 'stdiobuf') would be
easy to use.  It would not require modifying every other utility.

It's much better to have a 'nohup' program, than to add a '--nohup'
option to every other standard utility.  Similarly, it'd be much
better to have a 'stdiobuf' program, than to add a '--line-buffer'
option to every other standard utility.

> why does grep have the --line-buffered option for example?

I don't know; the grep documentation doesn't say much about that
option.  But the need for the feature in general cannot be all that
great, if only 'grep' has it now, after all these years of
development.  And if we can figure out a better way of doing it than
'grep' does it, we should do it the better way.