03-22-2011
To be honest, I do not really understand your question.
What exactly is the problem?
Just a quick thing about your code changes: They would not change anything except for the puts().
read() returns either -1 on error or the number of bytes read. The -1 case will call err_sys which will exit the whole program. So Read() will always return something >= 0
8 More Discussions You Might Find Interesting
1. Programming
Hello,
If i have 2 strings str1 and str2, i would like to copy/concatenate str2 to str1, from 1st bit leaving the 0th bit.
How do i do it? (2 Replies)
Discussion started by: jazz
2 Replies
2. Programming
hello socket programming expert,
I having difficulties in understanding how select() function in socket programming work.... I'm trying to create my own peer-to-peer chat or file transfer program by using the select() function.... Therefore does anyone had any tutorial or source code that... (4 Replies)
Discussion started by: draggy
4 Replies
3. Programming
I have a socket and a message queue over which i am trying to multiplex input using select().
When data comes over socket the select works but when it comes over message queue the select is not detecting it .
Create_Q gets the identifier of the messege queue.
... (1 Reply)
Discussion started by: shaurya.rastogi
1 Replies
4. UNIX for Advanced & Expert Users
Hi,
I was porting ipv4 application to ipv6; i was done with TCP transports. Now i am facing problem with SCTp transport at runtime.
To test SCTP transport I am using following server and client socket programs. Server program runs fine, but client program fails giving Invalid Arguments for... (0 Replies)
Discussion started by: chandrutiptur
0 Replies
5. IP Networking
I need clarification on whether it is okay to set socket options on a listening socket
simultaneously when it is being used in an accept() call?
Following is the scenario:-
-- Task 1 - is executing in a loop - polling a listen socket, lets call it 'fd', (whose file descriptor is global)... (2 Replies)
Discussion started by: jake24
2 Replies
6. Programming
I have created two sockets and binded both. My requirement is that 2nd socket must send/ recv data only on expiration of timeval(tv). but the 1st socket must keep on send/recv the data without waiting for the 2nd socket completion......
I have posted my code below......
In this code the 2nd... (3 Replies)
Discussion started by: naresh046
3 Replies
7. Windows & DOS: Issues & Discussions
Hello everyone.
I bought a dell laptop (XPS M1330) online which came without a hard drive. There is a Windows Vista Ultimate OEMAct sticker with product key at the bottom case. I checked dell website (here) for this model and it says this model supports both 32 and 64-bit version of Windows... (4 Replies)
Discussion started by: milhan
4 Replies
8. UNIX for Beginners Questions & Answers
Hi,
Below is the sample file:
$ cat x.txt
MDSYS|OGIS_GEOMETRY_COLUMNS|TABLE
MDSYS|OGIS_SPATIAL_REFERENCE_SYSTEMS|TABLE
MDSYS|SDO_IDX_TAB_SEQUENCE|SEQUENCE
MDSYS|SDO_PREFERRED_OPS_USER|TABLE
MDSYS|SDO_ST_TOLERANCE|TABLE
MDSYS|SDO_TOPO_DATA$|TABLE
MDSYS|SDO_TOPO_RELATION_DATA|TABLE... (4 Replies)
Discussion started by: newbie_01
4 Replies
LEARN ABOUT PHP
pcap_get_selectable_fd
PCAP_GET_SELECTABLE_FD(3PCAP) PCAP_GET_SELECTABLE_FD(3PCAP)
NAME
pcap_get_selectable_fd - get a file descriptor on which a select() can be done for a live capture
SYNOPSIS
#include <pcap/pcap.h>
int pcap_get_selectable_fd(pcap_t *p);
DESCRIPTION
pcap_get_selectable_fd() returns, on UNIX, a file descriptor number for a file descriptor on which one can do a select() or poll() to wait
for it to be possible to read packets without blocking, if such a descriptor exists, or -1, if no such descriptor exists. Some network
devices opened with pcap_create() and pcap_activate(), or with pcap_open_live(), do not support select() or poll() (for example, regular
network devices on FreeBSD 4.3 and 4.4, and Endace DAG devices), so -1 is returned for those devices.
Note that in:
FreeBSD prior to FreeBSD 4.6;
NetBSD prior to NetBSD 3.0;
OpenBSD prior to OpenBSD 2.4;
Mac OS X prior to Mac OS X 10.7;
select() and poll() do not work correctly on BPF devices; pcap_get_selectable_fd() will return a file descriptor on most of those versions
(the exceptions being FreeBSD 4.3 and 4.4), but a simple select() or poll() will not indicate that the descriptor is readable until a full
buffer's worth of packets is received, even if the read timeout expires before then. To work around this, an application that uses
select() or poll() to wait for packets to arrive must put the pcap_t in non-blocking mode, and must arrange that the select() or poll()
have a timeout less than or equal to the read timeout, and must try to read packets after that timeout expires, regardless of whether
select() or poll() indicated that the file descriptor for the pcap_t is ready to be read or not. (That workaround will not work in FreeBSD
4.3 and later; however, in FreeBSD 4.6 and later, select() and poll() work correctly on BPF devices, so the workaround isn't necessary,
although it does no harm.)
Note also that poll() doesn't work on character special files, including BPF devices, in Mac OS X 10.4 and 10.5, so, while select() can be
used on the descriptor returned by pcap_get_selectable_fd(), poll() cannot be used on it those versions of Mac OS X. Kqueues also don't
work on that descriptor. poll(), but not kqueues, work on that descriptor in Mac OS X releases prior to 10.4; poll() and kqueues work on
that descriptor in Mac OS X 10.6 and later.
pcap_get_selectable_fd() is not available on Windows.
RETURN VALUE
A selectable file descriptor is returned if one exists; otherwise, -1 is returned.
SEE ALSO
pcap(3PCAP), select(2), poll(2)
5 April 2008 PCAP_GET_SELECTABLE_FD(3PCAP)