Programming :: Read Data From A Socket?

Aug 24, 2010

I need to read data from a socket but it should be always listening because data arrives continuously .. I thought something like this would do it but it doesn't work .... I already set the socket options before

Code: char databuf[1024];
int datalen = sizeof(databuf);
if(read(sd, databuf, datalen) < 0)
{

[Code]....

View 9 Replies


ADVERTISEMENT

Programming :: Timer In Socket Programming - Wait For X Sec After Read() And Then Disconnect The Client Connection

Mar 8, 2011

I have a server listening on incoming client connections. Once the client establishes SSL connection with the server, the server waits on read() from the client. Only Client can disconnect the connection. I want to have a timer in the server program to wait for x secs after read() and then disconnect the Client connection.

View 3 Replies View Related

Programming :: Get Data From Serial Port Function Read() Blocks When Data Not Available?

Jun 11, 2009

I am using read() in c++ to get data from a serial port. However, if no data is available on the serial port the function blocks until dta arrives.Example code:

//------------------------------------------------------------
char m_readBuffer[255] = {0};
char* p_curChar = m_readBuffer;

[code]...

View 1 Replies View Related

Programming :: Receiving Wrong Data On Winsock From Unix Socket

Jan 28, 2011

currently I've got a big problem on programming with sockets. I use the winsock2 API and want to receive data from a multicast adress running on a UNIX-PC. The connection works fine and I really receive data from this group, but as it seems not the right packages. The received data is saved in a char[]. E.g. at received_msg[12] is a float value. This one I would like to read out, convert and use it in later progress the next value is y at received_msg[16]. The same Code works on a Unix PC with unix sockets but converted to winsock I've got the described problem and I have to make this code work under windows.

Here a piece of the code (received_msg[12]='3f'):

Buffer is a struct containing the two float values x and y. If I convert the char as this under windows the value of x is a huge number. The correct value is around 192, so receveid_message[12] should be 1.92. Could it be that the Unix-PC is sending data in an other way than the winsock receive it?

View 2 Replies View Related

Programming :: Data Directory In Automake - Data Is Always Read-only ?

May 9, 2010

I have some data files that should be distributed with my program. Using dist_pkgdata_DATA in Makefile.am, I get these files installed to /usr/local/data/share/package-name. The problem is that data is read-only, and my program needs to modify it. Playing with dist_sharedstate_DATA, dist_localstate_DATA, dist-data_DATA varibles, I got different installation directories, like /usr/local/com, usr/local/var, but data is always read-only.

How can I distribute modifiable data files with my package? I need some common directory for all users, or maybe local data in a user directory.

View 1 Replies View Related

Programming :: Socket Programming - Detect Whether A Client Socket Is Closed / Active?

Mar 8, 2011

iam just trying to connect to server which accepts one client and server will read(blocking operation) infinitely, but After closing the client socket the server "read operation" is returning zero and "errno variable(in errno.h)" value is also zero. how can i detect whether a client socket is closed/active..?

client.c
Serv_Addr.sin_family = AF_INET;
Serv_Addr.sin_addr.s_addr = inet_addr("127.0.0.1");
Serv_Addr.sin_port = htons(26553);
if( 0 > connect (Serv_Fds,&Serv_Addr,sizeof(Serv_Addr)) )
{
perror("connect");
return 0;
[Code]....

View 3 Replies View Related

Programming :: Possible To Open A Symlink (won't Follow) And Read Data From It?

Nov 9, 2010

I try to use open(2) system call, and I find one relevant flag: O_NOFOLLOW. But it will only return -1 rather than the symlink's file descriptor

View 5 Replies View Related

Programming :: Read Unknown Data Length From Usb Pipe?

Aug 12, 2010

I've written a usb device driver and a program that sends and receives data over the bulk pipe. The read function sometimes returnsI'm reading an unknown amount of data. However, using a usb tracker I can see that the correct data is being sent.The error only occurs sometimes.I expect that the read function is told to read more data that it receives it would fail and return -1, however if this was the case then every read call would fail.

View 4 Replies View Related

Programming :: Read Some Data From Controller Using Serial Port?

Aug 25, 2010

i want to try with a small application in linu in that i want to read some data from controller using serial port and i wanna transfor that data to another meachin in the network for this i want serial port interfacing programming as well as socket programming.

View 1 Replies View Related

General :: Socket Programming - Feed Some Words One By One To The Socket

Jul 6, 2010

i'm writing a simple program of client socket program. Here below is the code sample which i'm writing...

Code:
//tcp_client.c
#include <stdio.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <netdb.h>
#include<string.h>
#include<stdlib.h>
[Code].....

the above code works fine.if we copmile and run ./a.exe 192.xx.xx.xxx 1111 and press enter it works fine..everytime it asks "Please enter the message: " and if give that will be displayed in server. but my problem is i dont want to print everytime "Please enter the message: " i just want to feed some words one by one to the socket.

View 4 Replies View Related

Programming :: Setsockopt : Socket Operation On Non-socket Getting Error?

Mar 30, 2009

im getting that error in my code for some reason. I compiled my code, and when i try to run this server it throws me an error on my call to setsocketopt(). The only way it can reach that part of my loop is if it succeeds when it calls sock() so I dont understand why the error says its an operation on a non-socket. Im just trying to set up a server to pass messages from a client to it a viceversa. Here is the code:

Code:
int main()
{
int socket_fd, new_socket_fd, k;
struct addrinfo hints, *server_info, *p;
struct sockaddr_storage peer_address;
code....

View 7 Replies View Related

Programming :: Serial Port Data Read Time Interval?

Oct 30, 2010

I am writing a C program which reads data over serial port. While reading data, if I send my data(which is a 13 byte structure) periodic with a period of 1 second for 10 times I read it without problem and I read the data 10 times as I sent and as I expectBut if I send data continuousuly(without any time interval between each sending) 10 times I can only read 1 of them(I can only read it once).

View 11 Replies View Related

Programming :: Debian Serial Port Read() Return Wrong Data?

Jul 6, 2010

I am implementing a simple serial protocol where my ARM9 board, running Linux is communicating to a slave peripheral board. The Master sends a 12 byte data stream and the peripheral board returns status in a 23 byte response. The serial port is opened in raw mode. It works perfectly on 44 reads; however, on the 45 read the data returned from the read() is incorrect. I've framed what's being sent on an oscope and it is correct.The coincidence is that 23 x 44 = 1012. It's as though the receive buffer is 1K and when I go past the boundary I get bad data. The read following the bad one is good again.I've tried flushing the buffer before reading but get the same result.Here's the port initialization code:

Code:
int initport(int fd)
{

[code]...

View 4 Replies View Related

Networking :: Serial Port : Read Data, Not Reading Complete Data?

Mar 5, 2010

I have an application where I am sending data via serial port from PC1 (Java App) and reading that data in PC2 (C++ App). The problem that I am facing is that my PC2 (C++ App) is not able to read complete data sent by PC1 i.e. from my PC1 I am sending 190 bytes but PC2 is able to read close to 140 bytes though I am trying to read in a loop.Below is code snippet of my C++ AppOpen the connection to serial port

Code:
serialfd = open( serialPortName.c_str(), O_RDWR | O_NOCTTY | O_NDELAY);
if (serialfd == -1)

[code]...

View 5 Replies View Related

Networking :: Socket Timeout Happening Despite Data Being Available?

Dec 29, 2010

I am using select to read the data from socket. on a load of 25 req per second, for some req i am getting the timeout in select (returning zero), but i am able to see the data on TCP using wireshark. kindly suggest what could be the possible reasons.

View 5 Replies View Related

Ubuntu Servers :: SSH Error: Read From Socket Failed: Connection Reset By Peer?

Dec 8, 2010

figure out this error?

Code:
kradalby@hpcompaq6530b-laptop ~/.ssh $ ssh -vvv -p 110 kradalby@dfekt.no
OpenSSH_5.5p1 Debian-5+b1, OpenSSL 0.9.8o 01 Jun 2010

[code]....

View 3 Replies View Related

Programming :: Socket And Timer Programming - Server Doesn't Execute Any Msg Which Client Sent

May 16, 2011

i have a server program which accept multiple client connection and am using polling. like every 2 secs it will look to client whether any data is received after it binded. i have used setitimer but there is runtime error i got.. the server accept all client connection but doesn't execute any msg which client sent.

#include<stdio.h>
#include<stdlib.h>
#include<sys/socket.h>
#include<sys/types.h>
#include<netdb.h>
#include<unistd.h>
#include<pthread.h>
#include<string.h>
[Code]....

View 1 Replies View Related

Programming :: Socket Programming While Displaying Received Message In File

May 11, 2011

i have problem in socket programming, while displaying received message in file,i got a problem... i cant able to write it in the file.... this is the code....

Code:
/* tcpserver.c */
#include <sys/types.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#include <stdio.h>
[Code]....

now my problem is run time error i can able to create file but i cant able to write file....log.txt contain nothing.... as here i have give sample code... dont say not initialising function and all.... i have initialised , please only see func1() - my problem is only not able to write msg which i got received from the client..

View 2 Replies View Related

Programming :: Use Socket Programming In Order To Implement Chatting Feature?

Aug 25, 2010

how to use socket programming in order to implement chatting feature

View 5 Replies View Related

Programming :: Socket Programming: Insertion Of 0x00 Into The Stream?

Dec 5, 2010

When sending data over the socket, the sending socket includes 0x00 after each sent byte. I wonder how this can be avoided -- I just want to transfer the data in the tx_buffer as it is.

# ./serv &
[1] 6895
# ./EUG 127.0.0.1
EUG: Data to be transmitted: 0x35 0x32 0x30 0xff 0x03 0x31
EUG: Data - #Bytes transmitted: 6
./serv: Here is the message: '5'

[Code]...

View 3 Replies View Related

Programming :: Socket Programming Using Php - Swap A Client Ip And Port?

Mar 28, 2011

Is it possible to swap a client ip and port ? This is what I am trying to do. Let say you have Comp1 and Comp2 And you have Server between them. My goal is to get Comp1 and Comp2 know each others IP So Comp1 connects to server And server stores comp1's IP In a text file or other place And Comp2 connect to server And server also stores his info And then both comp1 and comp2 dowload the tex file And use the info on it.

View 9 Replies View Related

Programming :: Build Ip Packet With C,socket Programming?

Jan 30, 2011

How can we build a packet using C?we have a structure called sockaddr_in which is use to for IPv4,so that we can define address,port and etc in this way:

Code:
struct sockaddr_in sock;
sock.sin_family=AF_INET;

[code]...

View 5 Replies View Related

Programming :: Raw Socket Programming ( Head Is Going To Explode )?

Nov 11, 2010

This is my main question:Quote: In raw socket sniffing: how do I copy data from a structure into a char[] or pointer? My problem: I started doing some raw socket programming in OpenWRT (I'm a newbie) for research. It's been a long time since the last time I programmed in C, so here's my newbie question/problem.

I'm receiving packets and using an .h file with the structures to get the information of each 802.11 packet in monitor mode (attached to this post).My (simple) goal is to get the Tx MAC Address. No luck. This is my "read the prism header" function:

Code:
ParsePrismHeader(unsigned char *packet,int len)
{
wlan_header *wlan;ieee_802_11_header *i802;u_int16_t eth_type;
unsigned char *mac;unsigned char *mac2;
wlan = (wlan_header *)packet;
i802 = (ieee_802_11_header *)(packet + wlan->msglen);

[Code]...

View 3 Replies View Related

Programming :: Send File Through Raw Socket Using C Programming

Jul 23, 2010

I am currently doing a research on video transmission over wireless LAN. I tend to transmit my offline file (xx.svc) from server to client.It may sound stupid (since I have a very little knowledge about c programming and raw socket), but my biggest challenges is that when I want to write the file to the buffer, how actually to define/include the file at the programming coding? where I need to locate the file? Is it at the same folder with my c programming, or somewhere in the linuxinclude folder?

Can anyone just give a simple example on how to include a file and write it into a buffer before send it through raw socket.

View 14 Replies View Related

Programming :: Socket Programming - Connect To An IRC Server In A C

Mar 16, 2010

I am looking to be able to connect to an IRC server in a C program. I have followed some instructions from an old book I have however it doesn't seem to be working. I've tried connecting to localhost on my ssh port and it still doesn't want to work. This is what I have so far as a piece of skeleton test code:

Code:
#include<sys/types.h>
#include<stdio.h>
#include<stdlib.h>
#include<sys/socket.h>
#include<unistd.h>
#include<netinet/in.h>
#include<arpa/inet.h>
[Code]....

View 1 Replies View Related

Programming :: Socket Programming In Module Perl

Jul 21, 2010

Where is the perl module for programming with sockets?

View 4 Replies View Related

Programming :: Socket Programming Select Interface

Jan 15, 2010

I have currently had the need to go back to basic socket programming, and implemented a simple udp packet sender. But I realized I needed to be able to select which network interface to send the packets from.

The reason is so that one of the interfaces has vlan tagging, and I need my UDP packets to be accordingly vlan tagged. For example, one of the interfaces is eth1.200.

View 2 Replies View Related

Programming :: Socket Programming Send File

Jun 22, 2009

this is my client and server. I can receive text file. but I can't send other type of file like PDF,Docx,Odt

View 11 Replies View Related

Programming :: Send A UDP Msg Across A Socket?

Jan 24, 2011

Has anyone had an issue with gdb not being able to send a UDP msg across a socket?

I have ComponentA sending a msg to ComponentB utilizing gdb. ComponentB gets the msg. ComponentB sends a msg to ComponentC. ComponentC does stuff to the msg and sends a msg back to ComponentB using gdb.
ComponentB never seems to receive the 2nd message.

If I don't use gdb the messages Tx and Rx without an issue.

I'm flying blind without gdb to figure out a different bug.

View 3 Replies View Related

Programming :: Name A Socket By Bind?

Oct 20, 2010

How does bind system call names a socket.Code:bind(server_sockfd, (struct sockaddr *)&server_address, server_len);I see use of bind in majority of programms as above.But any of the arguments is not the name of socket.

View 1 Replies View Related







Copyrights 2005-15 www.BigResource.com, All rights reserved