9 More Discussions You Might Find Interesting
1. Programming
I take this question of the The Linux Programming Interface: A Linux and Unix System Programming page 652 exercise 30.1
I want someone to explain the under line statement because it sounds complex to me couldn't understand anything
30-1 Modify the program (thread_incr.c) so that each loop in... (3 Replies)
Discussion started by: fwrlfo
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2. Shell Programming and Scripting
Greetings,
I want to send broadcast udp from a script.
This works but is not broadcast:
echo -n "this is my message\r\n" | nc -u 192.168.0.12 5100
The broadcast version does not work:
echo -n "this is my message\r\n" | nc -u 192.168.0.255 5100
Suggestions on the right way to do this... (2 Replies)
Discussion started by: anotherstevest
2 Replies
3. Programming
hello to all
i want to use multithreading to my UDP broadcast server client program. will anyone help me by proving C code. i am working in fedora. also my requirement is POSIX compliance.please help me..... (6 Replies)
Discussion started by: moti12
6 Replies
4. Programming
Situation:
i have multiple pthread_create calls like this:
pthread_create(...., ThreadFunc1,.....);
pthread_create(...., ThreadFunc2,.....);
.
.
which i am using to create multiple threads.All the "ThreadFunc<i>" functions are actually calling same function "Receive" of a class using same... (3 Replies)
Discussion started by: Sastra
3 Replies
5. Shell Programming and Scripting
Hi
I need to insert 1million records into MySQL database, but it is taking lot of time as there is no bulk insert support.
I want to spawn 10 processes which will insert 100k records each parallely.
Can somebody help me with a example program to execute this task through shell scripting. (5 Replies)
Discussion started by: sach_roger
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6. UNIX for Advanced & Expert Users
I use FreeBSD7.0, I want to use UDP broadcast,my code is following:
/*udpcli01.c*/
int
main(int argc, char **argv)
{
int sockfd;
struct sockaddr_in servaddr;
if (argc != 2)
err_quit("usage: udpcli <IPaddress>");
bzero(&servaddr, sizeof(servaddr));
servaddr.sin_family = AF_INET;... (2 Replies)
Discussion started by: konvalo
2 Replies
7. UNIX for Advanced & Expert Users
Hi,
Can you please give me a suitable reference to learn multithreading programming in C in UNIX?
Thanks (3 Replies)
Discussion started by: naan
3 Replies
8. Programming
Hi all, I have a query about multithreading. What I would like to do is, at the start of my main update() function, start a couple of threads in parallel, once they are all complete carry on with my main update function.
void update() {
thread1->update(); // fluid solver
... (3 Replies)
Discussion started by: memoid
3 Replies
9. Programming
:confused:
Hi!
I have created a Multhreaded Application in Pro*C (using pthreads) with about 5 Threads running simultaneously. The Application is basically to Update a Centralized Table in Oracle, which updates different rows in the Table (Each Thread updates different rows!). The... (16 Replies)
Discussion started by: shaik786
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UDP(4) BSD Kernel Interfaces Manual UDP(4)
NAME
udp -- Internet User Datagram Protocol
SYNOPSIS
#include <sys/types.h>
#include <sys/socket.h>
#include <netinet/in.h>
int
socket(AF_INET, SOCK_DGRAM, 0);
DESCRIPTION
UDP is a simple, unreliable datagram protocol which is used to support the SOCK_DGRAM abstraction for the Internet protocol family. UDP
sockets are connectionless, and are normally used with the sendto(2) and recvfrom(2) calls, though the connect(2) call may also be used to
fix the destination for future packets (in which case the recv(2) or read(2) and send(2) or write(2) system calls may be used).
UDP address formats are identical to those used by TCP. In particular UDP provides a port identifier in addition to the normal Internet
address format. Note that the UDP port space is separate from the TCP port space (i.e., a UDP port may not be ``connected'' to a TCP port).
In addition broadcast packets may be sent (assuming the underlying network supports this) by using a reserved ``broadcast address''; this
address is network interface dependent.
Options at the IP transport level may be used with UDP; see ip(4).
MIB VARIABLES
The udp protocol implements a number of variables in the net.inet branch of the sysctl(3) MIB.
UDPCTL_CHECKSUM (udp.checksum) Enable udp checksums (enabled by default).
UDPCTL_MAXDGRAM (udp.maxdgram) Maximum outgoing UDP datagram size
UDPCTL_RECVSPACE (udp.recvspace) Maximum space for incoming UDP datagrams
udp.log_in_vain For all udp datagrams, to ports on which there is no socket listening, log the connection attempt (disabled by default).
udp.blackhole When a datagram is received on a port where there is no socket listening, do not return an ICMP port unreachable message.
(Disabled by default. See blackhole(4).)
ERRORS
A socket operation may fail with one of the following errors returned:
[EISCONN] when trying to establish a connection on a socket which already has one, or when trying to send a datagram with the desti-
nation address specified and the socket is already connected;
[ENOTCONN] when trying to send a datagram, but no destination address is specified, and the socket has not been connected;
[ENOBUFS] when the system runs out of memory for an internal data structure;
[EADDRINUSE] when an attempt is made to create a socket with a port which has already been allocated;
[EADDRNOTAVAIL] when an attempt is made to create a socket with a network address for which no network interface exists.
SEE ALSO
getsockopt(2), recv(2), send(2), socket(2), blackhole(4), inet(4), intro(4), ip(4)
HISTORY
The udp protocol appeared in 4.2BSD.
BSD
June 5, 1993 BSD
