Suppose i am writing a C program which is going to use Socket calls. I want to use a Unix port for my Socket.
How can i determine a port which is not already in use? (1 Reply)
Hello,
I actually try to make client-server program.
I'm using SCO OpenServer Release 5.0.0 and when I try to compile my code (by TELNET) I've got this error :
I'm just using this simple code :
and I get the same error if I use :
If someone can help me,
Thanks (2 Replies)
Can anyone plz me. I need a sample code for the following description.
Its urgent.
It is C/Socket program with the following descriptions:
NAME
coreadServer - Concurrent Readers Server.
coreadClient - Concurrent Readers Client.
SYNOPSIS
coreadServer <OutputFile>
coreadClient <n>... (1 Reply)
i m using sockets for setting up a connection between a server and a client.
When the clients gets connected to the server, its ip is conveyed to the server through one of the predefined structures in c library...
i save this ip address in an array....1st client's ip address goes to the zeroth... (1 Reply)
Hi,
I am trying to connect to more than 60 servers to perform some actions remotely. for this I am using ssh2. But its taking lot of time.
Though i am running the command in background, still its taking long time to execute..
Any one let me know can we use sockets instead of ssh2 for... (3 Replies)
hi guys i got this code trying to make connection between the server and multi clients but when i do ./server i got message server waiting then when i run ./client it says client 1 nosuch file i dont know whats that should i use any argument plz help how to compile and run and whats the expected... (1 Reply)
in socket programming how can i : Create for example 3 blank files, namely: server, client, network
•Server: act as servers/provider, will receive all requests from different client
•Client: requesters
•Network: middle-layer of communication between server & client
any tips or... (6 Replies)
i'm doing a simple program in socket programming on c i have server that can handle 2clients in a single machine i'm running ubuntu linux so i got it work but the probelm when clients send a message the server will echo it but i cant distinguish which client send the message client 1 or client... (7 Replies)
Hi All
I am getting an error when using the below code
Receiver
use IO::Socket;
$sock = new IO::Socket::INET (LocalHost => 'goldengate',
LocalPort => 1200,
Proto => 'tcp',
Listen => 5,
Reuse => 1
);
die "Socket could not be created. Reason: $!" unless $sock;
while ($new_sock =... (5 Replies)
Discussion started by: parthmittal2007
5 Replies
LEARN ABOUT BSD
fcntl
FCNTL(2) System Calls Manual FCNTL(2)NAME
fcntl - file control
SYNOPSIS
#include <fcntl.h>
res = fcntl(fd, cmd, arg)
int res;
int fd, cmd, arg;
DESCRIPTION
Fcntl provides for control over descriptors. The argument fd is a descriptor to be operated on by cmd as follows:
F_DUPFD Return a new descriptor as follows:
Lowest numbered available descriptor greater than or equal to arg.
Same object references as the original descriptor.
New descriptor shares the same file pointer if the object was a file.
Same access mode (read, write or read/write).
Same file status flags (i.e., both file descriptors share the same file status flags).
The close-on-exec flag associated with the new file descriptor is set to remain open across execv(2) system calls.
F_GETFD Get the close-on-exec flag associated with the file descriptor fd. If the low-order bit is 0, the file will remain open
across exec, otherwise the file will be closed upon execution of exec.
F_SETFD Set the close-on-exec flag associated with fd to the low order bit of arg (0 or 1 as above).
F_GETFL Get descriptor status flags, as described below.
F_SETFL Set descriptor status flags.
F_GETOWN Get the process ID or process group currently receiving SIGIO and SIGURG signals; process groups are returned as negative
values.
F_SETOWN Set the process or process group to receive SIGIO and SIGURG signals; process groups are specified by supplying arg as nega-
tive, otherwise arg is interpreted as a process ID.
The flags for the F_GETFL and F_SETFL flags are as follows:
O_NONBLOCK Non-blocking I/O; if no data is available to a read call, or if a write operation would block, the call returns -1 with the
error EWOULDBLOCK.
O_APPEND Force each write to append at the end of file; corresponds to the O_APPEND flag of open(2).
O_ASYNC Enable the SIGIO signal to be sent to the process group when I/O is possible, e.g., upon availability of data to be read.
RETURN VALUE
Upon successful completion, the value returned depends on cmd as follows:
F_DUPFD A new file descriptor.
F_GETFD Value of flag (only the low-order bit is defined).
F_GETFL Value of flags.
F_GETOWN Value of file descriptor owner.
other Value other than -1.
Otherwise, a value of -1 is returned and errno is set to indicate the error.
ERRORS
Fcntl will fail if one or more of the following are true:
[EBADF] Fildes is not a valid open file descriptor.
[EMFILE] Cmd is F_DUPFD and the maximum allowed number of file descriptors are currently open.
[EINVAL] Cmd is F_DUPFD and arg is negative or greater than the maximum allowable number (see getdtablesize(2)).
[ESRCH] Cmd is F_SETOWN and the process ID given as argument is not in use.
SEE ALSO close(2), execve(2), getdtablesize(2), open(2), sigvec(2)BUGS
The asynchronous I/O facilities of O_NONBLOCK and O_ASYNC are currently available only for tty and socket operations.
4.2 Berkeley Distribution Nov 30, 1994 FCNTL(2)