topic Re: What was /dev/tcp used for on RedHat Rel3? in Operating System - Linux

What was /dev/tcp used for on RedHat Rel3?

James Brand — Tue, 10 Jul 2007 15:37:22 GMT

It's not there on RedHat Rel4 and Tuxedo had been configured to use it on Rel3. All Google returns are some references to perl/shell programming tricks using this device file, such as

exec 3<>/dev/tcp/www.google.com/80
echo -e "GET / HTTP/1.1\n\n">&3
cat <&3

Obviously /dev/tcp is not needed or it would be there on Rel4. Does anyone know anything about /dev/tcp?

Thanks,
Jim

Re: What was /dev/tcp used for on RedHat Rel3?

Ivan Ferreira — Tue, 10 Jul 2007 15:51:00 GMT

See man bash:

/dev/tcp/host/port If host is a valid hostname or Internet address, and port is an integer port number or service name, bash attempts to open a TCP connection to the corresponding socket.

/dev/udp/host/port If host is a valid hostname or Internet address, and port is an integer port number or service name, bash attempts to open a UDP connection to the corresponding socket.

Re: What was /dev/tcp used for on RedHat Rel3?

Steven E. Protter — Tue, 10 Jul 2007 15:56:15 GMT

Shalom Jim,

Hmmm. Driver for tcp?

They either built it into the kernel or used another name for it in RH 4.

SEP

Re: What was /dev/tcp used for on RedHat Rel3?

Vitaly Karasik_1 — Wed, 11 Jul 2007 01:24:21 GMT

/dev/tcp supported iBCS2 emulation for supporting Solaris, etc. software.

It seems like recent 2.6 kernels doesn't support iBCS2 anymore.

http://www.linuxjournal.com/article/2809 Using iBCS2 Under Linux

Re: What was /dev/tcp used for on RedHat Rel3?

James Brand — Wed, 11 Jul 2007 08:56:55 GMT

Our Tuxedo developers have gotten their code to work without using /dev/tcp. Thanks to all for responding. This was a strange one.

Jim