Solved

how to echo CTRL-C to netcat or stop netcat from expecting CTRL-C to terminate?

Posted on 2006-06-10
3
3,383 Views
Last Modified: 2008-02-26
i need to send "test" regularly with a cronjob to 192.168.1.99:8000

currently the only solution i found was sheduling this script:
#!/bin/bash
echo "test" | netcat 192.168.1.99 8000 &
NETCATPID=$!
sleep 1
kill -s SIGINT $NETCATPID

it there a more beautiful solution to echo the ctrl-c directly after "test" ?
i also don't like the "sleep", which seems to be necessary
what if sending "test" takes longer?

thanks,
robert

0
Comment
Question by:robert_skywalker
[X]
Welcome to Experts Exchange

Add your voice to the tech community where 5M+ people just like you are talking about what matters.

  • Help others & share knowledge
  • Earn cash & points
  • Learn & ask questions
3 Comments
 
LVL 34

Assisted Solution

by:Duncan Roe
Duncan Roe earned 200 total points
ID: 16879326
You could do what you want with "expect" http://sourceforge.net/projects/expect
Instead of using netcat, you would telnet 192.168.1.99 8000. If "test" gets a response, you could specifically wait for that response. Other wise wait fior a bit, send ^] to escape to telnet command processor, send q\r
Or just kill the telnet process (not so neat)
0
 
LVL 51

Expert Comment

by:ahoffmann
ID: 16884447
> .. need to send "test" regularly
what is regulary?
should test be the URL-path or a part of the HTTP header? Is it HTTP anyway?
0
 
LVL 5

Accepted Solution

by:
devrick0 earned 300 total points
ID: 16884968
I wrote something in python that checks a tcp host & port.  So if you throw this into a script, name it connect.py then you can run it like this:
./connect.py [host] [port]
(the usage statement will let you know if you don't have the correct number of arguments)
Example:
./connect.py 192.168.1.99 8000

#/usr/bin/python
import socket, sys

def try_conn_tcp():
        try:
                print "Attempting tcp connection on port %d" % (port)
                s = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
                s.connect((host, port))
                print "Connection to %s on port %d succeeded." % (host, port), "\n"
                sys.exit(1)
        except socket.error, e:
                print "\nTCP Socket Connection error : %s" % e, "\n"

if __name__=='__main__':
        usage = "\nUsage: connect.py [host] [port]\n"
        if len(sys.argv) < 3:
                print >> sys.stderr, usage
                sys.exit(1)
        host = sys.argv[1]
        textport = sys.argv[2]
        port = int(textport)
        try_conn_tcp()
0

Featured Post

Free Tool: Subnet Calculator

The subnet calculator helps you design networks by taking an IP address and network mask and returning information such as network, broadcast address, and host range.

One of a set of tools we're offering as a way of saying thank you for being a part of the community.

Question has a verified solution.

If you are experiencing a similar issue, please ask a related question

Suggested Solutions

Title # Comments Views Activity
Where is my core dump file in Ubuntu? 12 461
Shell script awk command 2 117
How to import linux vhd to sccvmm 1 165
Unix / Linux grid computing 5 169
Have you ever been frustrated by having to click seven times in order to retrieve a small bit of information from the web, always the same seven clicks, scrolling down and down until you reach your target? When you know the benefits of the command l…
The purpose of this article is to demonstrate how we can upgrade Python from version 2.7.6 to Python 2.7.10 on the Linux Mint operating system. I am using an Oracle Virtual Box where I have installed Linux Mint operating system version 17.2. Once yo…
Although Jacob Bernoulli (1654-1705) has been credited as the creator of "Binomial Distribution Table", Gottfried Leibniz (1646-1716) did his dissertation on the subject in 1666; Leibniz you may recall is the co-inventor of "Calculus" and beat Isaac…
In an interesting question (https://www.experts-exchange.com/questions/29008360/) here at Experts Exchange, a member asked how to split a single image into multiple images. The primary usage for this is to place many photographs on a flatbed scanner…

733 members asked questions and received personalized solutions in the past 7 days.

Join the community of 500,000 technology professionals and ask your questions.

Join & Ask a Question