Question

I’m on RedHat, I need to get the value in the Release field.
Take “wget” for an example.

Here’s the output I’m expected to get

WGET:    1.4.el6

Here’s the output from rpm -qi wget

[luke@machine ~]# rpm -qi wget
Name        : wget                         Relocations: (not relocatable)
Version     : 1.12                              Vendor: Red Hat, Inc.
Release     : 1.4.el6                       Build Date: Mon May 10 14:56:18 2010
Install Date: Wed Oct  3 16:48:58 2012         Build Host: x86-012.build.bos.redhat.com
Group       : Applications/Internet         Source RPM: wget-1.12-1.4.el6.src.rpm
Size        : 1877597                          License: GPLv3+ and GFDL
Signature   : RSA/8, Mon Aug 16 21:21:35 2010, Key ID 199e2f91fd431d51
Packager    : Red Hat, Inc. <http://bugzilla.redhat.com/bugzilla>
URL         : http://wget.sunsite.dk/
Summary     : A utility for retrieving files using the HTTP or FTP protocols

How can I write a script to extract the “1.4.el6” from the Release field.

I currently have

#!/bin/bash
RELwg= rpm -qi wget
# Do string manipulation of $RELwg here
wg="WGET:   "
echo $wg$RELwg

But here’s the output I get;

Release     : 1.4.el6                       Build Date: Mon May 10 14:56:18 2010
WGET:

I know I have to do some string extraction, to get the number.

• Get the index of the 1, seems to always be constant at 15
• Get the index of the B in Build Date
• Get the sub string inbetween 15 and whatever B is

Removing the space between “RELwg= rpm -qi wget” in my current script, I just get an error saying that

./GetRPMVersions.sh: line 12: -qi: command not found

Mainly my current predicament is to addign the ouput of rpm -qi wget | grep Release to a variable.

Any input on the string manipulation is welcome.

Answer 1

something like

RELwg=$(rpm -qi wget | awk -- '/^Release/ { print $3 }')