Unix bidirectional pipe on commandline

Posted by John W on Super User See other posts from Super User or by John W
Published on 2012-09-19T21:31:13Z Indexed on 2012/09/19 21:40 UTC
Read the original article Hit count: 163

Filed under:

linux

|

redirection

|

pipe

|

netcat

I've been able to use this linux command to connect Netcat to a serial port:

nc -l 80 <> /dev/ttyS0

I would like to be able to log this transaction. My backup plan is to use Wireshark to monitor the netcat stream, but ideally I'd like to do something like this:

cat /dev/ttyS0 | tee upstream.bin | nc -l 80| tee downstream.bin | /dev/ttyS0

This tries to open ttyS0 twice and therefore throws a permissions error. Does anyone know a smarter way to do this?

© Super User or respective owner

Related posts about linux

apt-get install and update fail

as seen on Ask Ubuntu - Search for 'Ask Ubuntu'
I've got a problem with apt-get update and apt-get install ... commands . every time update or installing fails and errors are : Get:1 http://dl.google.com stable Release.gpg [198B] Ign http://dl.google.com/linux/chrome/deb/ stable/main Translation-en_US Get:2 http://dl… >>> More
kernel module compiling error

as seen on Ask Ubuntu - Search for 'Ask Ubuntu'
sh@ubuntu:/home/ccpp/helloworld$ make gcc-4.6 -O2 -DMODULE -D_KERNEL_ -W -Wall -Wstrict-prototypes -Wmissing-prototypes -isystem /lib/modules/`uname -r`/build/include -c -o hello-1.o hello-1.c hello-1.c:4:0: warning: "MODULE" redefined [enabled by default] <command-line>:0:0: note: this is… >>> More
Build-Essentials installation failing

as seen on Ask Ubuntu - Search for 'Ask Ubuntu'
I am having trouble accessing the several critical header files that show to be a part of the build process. The "Ubuntu Software Center" shows "Build Essentials" as installed: Next I did the following two commands, which did not improve the problem: ~$ sudo apt-get install build-essential [sudo]… >>> More
Updating Debian kernel

as seen on Super User - Search for 'Super User'
I'm trying to update my Debian machine to 2.6.32-46 (which is the new stable). However, after doing apt-get update my apt-cache search linux-image shows me: linux-headers-2.6.32-5-486 - Header files for Linux 2.6.32-5-486 linux-headers-2.6.32-5-686-bigmem - Header files for Linux 2.6.32-5-686-bigmem linux-headers-2… >>> More
Serial connection over a single USB cable (Windows to linux, or linux to linux)

as seen on Server Fault - Search for 'Server Fault'
I'm helping out with a project for an embedded device that only has USB and no serial. This device is running Linux. These days, when we need to connect to a serial port on a device we typically use a USB to serial adapter (on something like a phone system or a load balancing device, etc). I would… >>> More

Related posts about redirection

Windows 7 Folder Redirection (GPO)

as seen on Server Fault - Search for 'Server Fault'
Hi - I have been fighting this issue for a day or two now, so I am looking for some insight. I am taking over admin duties in a domain of 800 users, and the previous admins really did not employ much of any GPO settings for the clients of the Domain. In each site, there is a location on the file… >>> More
Mobile Device Detection and Redirection Using ASP.NET / MVC

as seen on Dot net Slackers - Search for 'Dot net Slackers'
This article explains approaches for ASP.NET mobile development to determine if an HTTP request is coming from a mobile phone and then redirecting the request to a page optimized for a mobile browser. >>> More
cdrom redirection fails on ILOM for Sun x4600 M2

as seen on Server Fault - Search for 'Server Fault'
We have been able to successfully redirect the ILOM on this x4600 M2 in the past, but for some reason now we are getting an error that says "CD-ROM image redirection failed to start": We have also launched the Storage Redirection service and that doesn't help. Launching it a second time to really… >>> More
Basic 301 Redirection Help

as seen on Server Fault - Search for 'Server Fault'
I am trying to learn redirection for a WordPress site of my own. I am testing the concept of redirecting a single WordPress post by using a dummy site. However, it doesn't seem to be working for me. I am trying to redirect www.perfectmatchmaker[dot]org/finding-the-right-matchmaker to www.perfectmatchmaker[dot]org/finding-the-perfect-matchmaker I… >>> More
Apache Redirect to Jboss SSL

as seen on Server Fault - Search for 'Server Fault'
I'm trying to have an SSL Connection to an Apache server on port 443 which I want to use to proxy connections to a JBoss server on a different port. The SSL certificates sit on the Jboss server not on the Apache server. Is it possible to redirect HTTPS traffic from Apache to the Jboss Server and… >>> More