Unix Programming - [socket] test if socket descriptor is valid

Author

[socket] test if socket descriptor is valid

mbm

2007-09-27, 7:35 am

Hi

Is it possible to check that a socket descriptor is valid before
receiveing data ( recv) ?

maybe fstat ?

Mark Holland

2007-09-27, 1:34 pm

"mbm" <mbmessaoud@yahoo.com> wrote in message
news:1190890077.826077.15620@57g2000hsv.googlegroups.com...
> Hi
>
> Is it possible to check that a socket descriptor is valid before
> receiveing data ( recv) ?
>
> maybe fstat ?

Why bother? recv will return EBADF if the descriptor is invalid
anyway. However you are correct - using fstat you can check the
st_mode field for the file type. Note this is only valid if fstat
returns correctly... you may have a completely invalid fd (e.g. you
previously closed this file) in which case fstat will return EBADF
also.

Mark