Tech Tip: TCP/IP Access Using bash

Any one knows why this wasn't enabled by default?

Works on Gentoo out of the box!

Worked right out of the box on Kubuntu 9.10

I've updated the script written by Joseph E. Tole
I tried his script, and it didn't work because I didn't have all dependencies and there was a version change in the resulting .deb
The updated script:

#!/bin/bash
# Written by Joseph E. Tole 09/29/09
#Updated by G. Geurts 09/30/09

# This creates and then changes to a new temporary directory. mktemp should always be used to avoid accidently using an active file/dir.
bash_source="$(/bin/mktemp -d)"
cd "${bash_source}"

# Install the bash source.
apt-get source bash

# Dependencies
# The -y flag causes apt-get to assume you said yes and not prompt for y/n to install
/usr/bin/sudo apt-get build-dep -y bash
/usr/bin/sudo apt-get install -y dpkg-dev fakeroot
cd bash-3.2

# This line changes the rules file which has the configure script options predefined in it. This causes the compile to now include network support.
/bin/sed -e 's/--disable-net-redirections/--enable-net-redirections/' -i debian/rules

# This creates new .deb packages for bash which is several but we only need to install one since the others are copies of what is already installed.
/usr/bin/dpkg-buildpackage -rfakeroot

# Install the .deb. The asterisk is used for architecture independence. In my case it * matches _amd64 but this is different on non 64 bix x86 systems.
/usr/bin/sudo /usr/bin/dpkg -i ../bash_3.2-[45]ubuntu1*.deb

# The line below puts bash on hold within the package manager so that it is not automatically upgraded. If it is then you will lose this functionality.
echo 'bash hold' | /usr/bin/sudo /usr/bin/dpkg --set-selections

I tried this on my Ubuntu system and it did not work. So I looked at the bash manpage and saw the following:

NOTE: Bash, as packaged for Debian, does not support using the /dev/tcp and /dev/udp files.

I just wanted to add then Debian and Ubuntu do not have this option as it is not compiled into bash on either of these systems by default. I have included a _quickly_written_ bash script below that will compile and install bash with network support. This works on Ubuntu 8.10 and 9.04 on AMD64 architecture and should work on x86 too and probably any architecture the Debian* system is installed on. Will likely work on any current Debian or Debian clone and if it is not current, then just the version of bash has to change (i.e. where we cd to bash-3.2 directory).

#!/bin/bash
# Written by Joseph E. Tole 09/29/09

# This creates and then changes to a new temporary directory. mktemp should always be used to avoid accidently using an active file/dir.
bash_source="$(/bin/mktemp -d)"
cd "${bash_source}"

# Install the bash source.
apt-get source bash

# Dependencies
# The -y flag causes apt-get to assume you said yes and not prompt for y/n to install
/usr/bin/sudo apt-get build-dep -y bash
/usr/bin/sudo apt-get install -y dpkg-dev
cd bash-3.2

# This line changes the rules file which has the configure script options predefined in it. This causes the compile to now include network support.
/bin/sed -e 's/--disable-net-redirections/--enable-net-redirections/' -i debian/rules

# This creates new .deb packages for bash which is several but we only need to install one since the others are copies of what is already installed.
/usr/bin/dpkg-buildpackage -rfakeroot

# Install the .deb. The asterisk is used for architecture independence. In my case it * matches _amd64 but this is different on non 64 bix x86 systems.
/usr/bin/sudo /usr/bin/dpkg -i ../bash_3.2-4ubuntu1*.deb

# The line below puts bash on hold within the package manager so that it is not automatically upgraded. If it is then you will lose this functionality.
echo 'bash hold' | /usr/bin/sudo /usr/bin/dpkg --set-selections