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Full Discussion: Using socket to test a TCP port
Top Forums Programming Using socket to test a TCP port Post 302516979 by Loic Domaigne on Monday 25th of April 2011 04:25:37 PM
Old 04-25-2011
Assuming that you're implementing a TCP client, you have the following possibilities:

1) The connect() is carried out in a separate thread; another thread implements the timer. Upon timeout, the connect thread can be cancelled since connect() is a cancellation point.

2) You raise a signal when a timer expired to the thread calling connect(). This will cause connect() to be interrupted. Only useful for single threaded program; for multi-threaded program use 1) or 3).

3) You use non blocking socket, see a the snippet below
Code:
flags=fcntl(fd, F_GETFL, 0);
fcntl(fd, F_SETFL, flags | O_NONBLOCK);
connect(fd,&addr,len);
...

Then you need to poll() for both read/write events:
Code:
struct pollfd fds;
fds.fd = fd;
fds.events = POLLIN | POLLOUT;
poll(&fds,1,timeout)
...

Error checking is omitted for your convenient (DISCLAIMER: DON'T do this for production code)

HTH, Loïc
 

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LEARN ABOUT DEBIAN

ekg2-remote

EKG2-REMOTE(1)						      General Commands Manual						    EKG2-REMOTE(1)

NAME

       ekg2-remote - remote User Interface for EKG2

SYNOPSIS

       ekg2-remote [OPTIONS] REMOTE-ENDPOINT

DESCRIPTION

       ekg2-remote  is a program which provides a remote user interface to an EKG2 instance that uses the "remote" plugin. It connects to EKG2 via
       a socket, and lets you use the program as if it was running locally.

       The motivation behind this program was to be able to use EKG2 on a low performance machine with limited memory and CPU resources.

OPTIONS

       -c, --charset=CHARSET
	      forces the charset name to use,

       -p, --password=PASSWORD
	      sets the password,

       -T, --test=FRONTEND
	      runs in test mode (for debugging), using FRONTEND user interface (default is ncurses),

       -F, --frontend=FRONTEND
	      uses FRONTEND user interface (default is ncurses),

       -m, --no-mouse
	      does not load mouse support,

       -U, --unicode
	      forces unicode support,

       -h, --help
	      displays a help message,

       -v, --version
	      displays program version and exits

       ENDPOINT specifies the EKG2 instance to connect to. The following are accepted:

       tcp:address:port
	      cleartext TCP/IP connection to given address and port

       tcps:address:port
	      SSL-encrypted TCP/IP connection to given address and port

       udp:address:port
	      UDP/IP connection to given address and port

       unix:socket-path
	      local (UNIX) connection to given socket-path

       pipe:fifo-path
	      local (pipe) connection to given fifo-path.  Currently unsupported.

SEE ALSO

       ekg2(1).  The full documentation for ekg2 is maintained as a Docbook manual.  See http://ekg2.org/ekg2book/ for an online version.

User Commands							    2008-03-05							    EKG2-REMOTE(1)
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