11-29-2007
Quote:
while (len)
{
int i=read(fd,p,len);
if (i < 0) { perror("read"); break; }
if (i == 0) break;
p+=i;
len-=i;
}
you had send me this code.....but I didnt able to understand why you had used
p+=i; where p is a char string ......
moreover I am getting more difficulties with code...i.e through pipe read end I am not able to read the data.....
when i check for strace -ppid its showing continously polling (for parent) with select
and child witing for msgrcv()......
10 More Discussions You Might Find Interesting
1. UNIX for Dummies Questions & Answers
1. If I use an software application(which connects to the database in the server) in my local pc, how many PID should be registered? Would there be PID for the session and another PID for socket connection?
2. I noticed (through netstat) that when I logged in using the my software application,... (1 Reply)
Discussion started by: pcx26
1 Replies
2. UNIX for Advanced & Expert Users
Hello,
I need help to replace the ................. of client.c that request the server implemented by server.c
------------------
Listing 1 - server.c
/* Inclusion des différentes librairies nécessaires */
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <string.h>
... (0 Replies)
Discussion started by: bounkolh
0 Replies
3. UNIX for Dummies Questions & Answers
Sorry if this is a stupid question!
I have been developing a Java application that I am deploying on both Unix and Linux servers, which uses lots of socket handling. When the server side connection is dropped by the server un-gracefully I have been seeing close_waits and null connections.
... (0 Replies)
Discussion started by: Vinnie
0 Replies
4. 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
5. 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
6. Programming
Hi all,
On the server side, one socket is used for listening, the others are used for communicating with the client.
My question is: if i want to set option for socket, which socket should be set on?
If either can be set, what's the different?
Again, what's the different if set option... (1 Reply)
Discussion started by: blademan100
1 Replies
7. Programming
Why does this socket function only read the first 1440 chars of the stream. Why not the whole stream ? I checked it with gdm and valgrind and everything seems correct...
#include <stdio.h>
#include <stdlib.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <string.h>
#include... (3 Replies)
Discussion started by: cyler
3 Replies
8. Programming
Dear Experts,
i am compiling my code in suse 4.1 which is compiling fine,
but at runtime it is showing me for socket programming error no 88
as i searched in errno.h it is telling me socket operation on non socket,
what is the meaning of this , how to deal with this error , please... (1 Reply)
Discussion started by: vin_pll
1 Replies
9. 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
10. Programming
Hello, I'm stuck and this is a matter which I need to resolve quite fast (but I couldn't post in the "Emergency" section); the problem is this :
I have created a chat program in which the client sends the sentence to the server and then the server should send it to all the clients connected,... (2 Replies)
Discussion started by: timmyyyyy
2 Replies
TEE(2) Linux Programmer's Manual TEE(2)
NAME
tee - duplicating pipe content
SYNOPSIS
#define _GNU_SOURCE /* See feature_test_macros(7) */
#include <fcntl.h>
ssize_t tee(int fd_in, int fd_out, size_t len, unsigned int flags);
DESCRIPTION
tee() duplicates up to len bytes of data from the pipe referred to by the file descriptor fd_in to the pipe referred to by the file
descriptor fd_out. It does not consume the data that is duplicated from fd_in; therefore, that data can be copied by a subsequent
splice(2).
flags is a series of modifier flags, which share the name space with splice(2) and vmsplice(2):
SPLICE_F_MOVE Currently has no effect for tee(); see splice(2).
SPLICE_F_NONBLOCK Do not block on I/O; see splice(2) for further details.
SPLICE_F_MORE Currently has no effect for tee(), but may be implemented in the future; see splice(2).
SPLICE_F_GIFT Unused for tee(); see vmsplice(2).
RETURN VALUE
Upon successful completion, tee() returns the number of bytes that were duplicated between the input and output. A return value of 0 means
that there was no data to transfer, and it would not make sense to block, because there are no writers connected to the write end of the
pipe referred to by fd_in.
On error, tee() returns -1 and errno is set to indicate the error.
ERRORS
EINVAL fd_in or fd_out does not refer to a pipe; or fd_in and fd_out refer to the same pipe.
ENOMEM Out of memory.
VERSIONS
The tee() system call first appeared in Linux 2.6.17; library support was added to glibc in version 2.5.
CONFORMING TO
This system call is Linux-specific.
NOTES
Conceptually, tee() copies the data between the two pipes. In reality no real data copying takes place though: under the covers, tee()
assigns data in the output by merely grabbing a reference to the input.
EXAMPLE
The following example implements a basic tee(1) program using the tee() system call.
#define _GNU_SOURCE
#include <fcntl.h>
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <errno.h>
#include <limits.h>
int
main(int argc, char *argv[])
{
int fd;
int len, slen;
if (argc != 2) {
fprintf(stderr, "Usage: %s <file>
", argv[0]);
exit(EXIT_FAILURE);
}
fd = open(argv[1], O_WRONLY | O_CREAT | O_TRUNC, 0644);
if (fd == -1) {
perror("open");
exit(EXIT_FAILURE);
}
do {
/*
* tee stdin to stdout.
*/
len = tee(STDIN_FILENO, STDOUT_FILENO,
INT_MAX, SPLICE_F_NONBLOCK);
if (len < 0) {
if (errno == EAGAIN)
continue;
perror("tee");
exit(EXIT_FAILURE);
} else
if (len == 0)
break;
/*
* Consume stdin by splicing it to a file.
*/
while (len > 0) {
slen = splice(STDIN_FILENO, NULL, fd, NULL,
len, SPLICE_F_MOVE);
if (slen < 0) {
perror("splice");
break;
}
len -= slen;
}
} while (1);
close(fd);
exit(EXIT_SUCCESS);
}
SEE ALSO
splice(2), vmsplice(2)
COLOPHON
This page is part of release 3.53 of the Linux man-pages project. A description of the project, and information about reporting bugs, can
be found at http://www.kernel.org/doc/man-pages/.
Linux 2012-05-04 TEE(2)