CODEWITHSUNDEEP
bashshellunixaix
Guillaume F.
Guillaume F.

Reputation: 135

Retrieve bash version in AIX

After the shellshock issue detected on Unix systems with bash, I have to create a script as part of my internship in a firm in order to update bash.

Prerequisites to the installation of the updated IBM bash*.rpm are:

I have a problem dealing with the second part, since the true bash version is given by command bash -version instead of rpm -qi bash which essentially gives the version/release of the installation package (and not neccessarily the true bash version).

Basically, my script goes like this:

if [[ bash installed ]] ; then
  if [[ bash version installed is < 4.2.50 ]] ; then
    install bash version 4.2.50
  fi
fi

bash -version returns a lot of text, and I would like to pick out the bash version.

So far, I've used the following command:

$ bash -version | grep version | awk '{print $4}' | head -n 1

That returns :

4.2.50(1)-release

Is there any way to retrieve the real bash version? I've played around with the sed command with no success.

Upvotes: 1

Views: 2869

Answers (2)

fedorqui
fedorqui

Reputation: 289715

I guess you can directly use the $BASH_VERSION variable:

$ echo "$BASH_VERSION"
4.2.47(1)-release

From man bash:

Shell Variables

BASH_VERSION

Expands to a string describing the version of this instance of bash.

Then, to check if the version is under or above 4.2.50 you can make use of sort -V to order them:

$ printf "%s\n%s\n" 4.2.50 $BASH_VERSION | sort -V
4.2.47(1)-release
4.2.50

$ printf "%s\n%s\n" 4.2.50 5.2.33 | sort -V
4.2.50
5.2.33

This should be enough for you to determine if your current bash version is under or above the desired one, just some head and tail is needed for the final result.

From man sort:

-V, --version-sort

natural sort of (version) numbers within text

Upvotes: 1

Avinash Raj
Avinash Raj

Reputation: 174706

Seems like you're trying to get output like this,

$ bash -version | awk -F'[ (]' '/version/{print $4;exit}'
4.3.11

Upvotes: 1

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