bidirectional popen

Thread view:

Enable EMail Alerts

Start New Thread

Thread rating:

Full Time Whiner - 21 Jan 2005 22:58 GMT

My jaguar man page states that POPEN can now be used bidirectionally.
Yet when I try the "r+" mode ("w+" and "a+", for good measure), I just
get an error (invalid arg).

In looking around, I found <http://www.hmug.org/man/3/popen.html>, which
warned "Deprecated: Mac OS X < 10.3.x". Does "deprecated" mean
"broken", in this case?

Does popen provide bidirectional capability in 10.3?

Is Apple just full of crap?

Reply to this Message

Eric Albert - 22 Jan 2005 05:18 GMT

> My jaguar man page states that POPEN can now be used bidirectionally.
> Yet when I try the "r+" mode ("w+" and "a+", for good measure), I just
[quoted text clipped - 3 lines]
> warned "Deprecated: Mac OS X < 10.3.x". Does "deprecated" mean
> "broken", in this case?

"Deprecated" in this case means "I have no idea where that web page came
from". :) popen is part of POSIX. Apple would be wrong to deprecate it
until a future POSIX standard does. I can't see any sign on Mac OS X
that would imply that popen is deprecated.

> Does popen provide bidirectional capability in 10.3?

Probably. What's your code?

-Eric

Signature

Eric Albert ejalbert@cs.stanford.edu
http://outofcheese.org/

Reply to this Message

Michael Ash - 22 Jan 2005 08:53 GMT

> My jaguar man page states that POPEN can now be used bidirectionally.
> Yet when I try the "r+" mode ("w+" and "a+", for good measure), I just
[quoted text clipped - 7 lines]
>
> Is Apple just full of crap?

This is a bug, although I don't know whether it qualifies as a bug in libc
or a documentation bug. If you look at the source code for Apple's libc,
there is *no* support for bidirectional popen whatsoever in the code.

I filed this as a bug with Apple with ID 3665139, and it's closed as a
duplicate.

Reply to this Message

Eric Albert - 22 Jan 2005 21:09 GMT

> > My jaguar man page states that POPEN can now be used bidirectionally.
> > Yet when I try the "r+" mode ("w+" and "a+", for good measure), I just
[quoted text clipped - 14 lines]
> I filed this as a bug with Apple with ID 3665139, and it's closed as a
> duplicate.

If you grab a copy of the Libc source from the Tiger WWDC preview
(<http://www.opensource.apple.com/darwinsource/WWDC2004/>), you'll see
that popen has bidirectional support there. In other words, it looks
like this has been fixed for Tiger.

-Eric

Signature

Eric Albert ejalbert@cs.stanford.edu
http://outofcheese.org/

Reply to this Message

Michael Ash - 23 Jan 2005 11:38 GMT

>>[bidirection popen() doesn't work]
>> This is a bug, although I don't know whether it qualifies as a bug in libc
[quoted text clipped - 8 lines]
> that popen has bidirectional support there. In other words, it looks
> like this has been fixed for Tiger.

Thanks for letting us know, that's good news. I was afraid they would
consider it a documentation bug and just "fix" the man page.

Reply to this Message

Mac Forum / Programming / Mac Programming / January 2005

bidirectional popen