Reading StandardOutput from a Process (no deadlock please)

[bob_jeffcoat]

Hi,

I'm trying to read the output and write the input of a process using
its StandardOutput/Input and I'd really like to check if the process
is waiting for input or whether it has output ready to be read. Is it
possible? It seems like a fairly simple thing to try and do but most
of the "read" functions I've tried seem to deadlock if there's nothing
to read due the process waiting for output. It's rubbish!

Even a simple "try for 100millieseconds and give up" would be ok, but
I can't see how to do that either.
any ideas?

Thanks

[=?Utf-8?B?dGJhaW4=?=]

Not sure how you are doing your I/O but iostream and streamreader have Peek
methods. Hope this helps.
--
Thom
"bo**********@hotmail.com" wrote:

Hi,

I'm trying to read the output and write the input of a process using
its StandardOutput/Input and I'd really like to check if the process
is waiting for input or whether it has output ready to be read. Is it
possible? It seems like a fairly simple thing to try and do but most
of the "read" functions I've tried seem to deadlock if there's nothing
to read due the process waiting for output. It's rubbish!

Even a simple "try for 100millieseconds and give up" would be ok, but
I can't see how to do that either.
any ideas?

Thanks

[UL-Tomten]

On Aug 21, 12:44 pm, [e-mail] wrote:

I'd really like to check if the process is waiting for input

I don't think this is possible. Are you sure you need it?

or whether it has output ready to be read.

See tbain's Peek() response.

deadlock

Technically, what you're describing is a "blocking read". Deadlocks
are (by definition) permanent.

[bob_jeffcoat]

On 21 Aug, 12:37, UL-Tomten <[e-mail]:

On Aug 21, 12:44 pm, [e-mail] wrote:

I'd really like to check if the process is waiting for input

I don't think this is possible. Are you sure you need it?

or whether it has output ready to be read.

See tbain's Peek() response.

deadlock

Technically, what you're describing is a "blocking read". Deadlocks
are (by definition) permanent.

Thanks for the responses.

I had a go with Peek(), but it's not great as sometimes it answers -1
but you can still do a successful ReadLine(). Think it may be
answering -1 for an empty line.

It's quite annoying.

Oh well, thanks anyway