RHEL / CentOS: Install and Activate Bash Autocomplete Feature

How do I use bash auto complete features with various command on CentOS / RHEL / Fedora / Scientific Linux based systems?

Tutorial details
Difficulty	Easy (rss)
Root privileges	Yes
Requirements	EPEL

Autocomplete is nothing but a collection of various hacks that specify how arguments are to be completed by Readline using complete built-in. By default, this feature is turned on many Linux distributions such as Debian Linux, Ubuntu Linux and more. However, this feature is not installed on RHEL based Linux distributions.

Installation

First, turn on the EPEL repo and type the following yum command to install bash-completion package:
# yum install bash-completion
Sample outputs:

 
Loaded plugins: product-id, rhnplugin, security, subscription-manager
This system is not registered to Red Hat Subscription Management. You can use subscription-manager to register.
This system is receiving updates from RHN Classic or RHN Satellite.
Setting up Install Process
Resolving Dependencies
--> Running transaction check
---> Package bash-completion.noarch 1:1.3-5.el6 will be installed
--> Finished Dependency Resolution
 
Dependencies Resolved
 
================================================================================
 Package                 Arch           Version              Repository    Size
================================================================================
Installing:
 bash-completion         noarch         1:1.3-5.el6          epel         215 k
 
Transaction Summary
================================================================================
Install       1 Package(s)
 
Total download size: 215 k
Installed size: 576 k
Is this ok [y/N]: y
Downloading Packages:
bash-completion-1.3-5.el6.noarch.rpm                     | 215 kB     00:00
Running rpm_check_debug
Running Transaction Test
Transaction Test Succeeded
Running Transaction
  Installing : 1:bash-completion-1.3-5.el6.noarch                           1/1
  Verifying  : 1:bash-completion-1.3-5.el6.noarch                           1/1
 
Installed:
  bash-completion.noarch 1:1.3-5.el6
 
Complete!

How do I use bash Autocomplete feature?

Then exits a login shell / ssh session and log back in using the following command:
# logout
Open a terminal or log in using ssh:
$ ssh nixcraft@server1.cyberciti.biz
Alternatively, use the following command to source completion code for bash:
$ . /etc/bash_completion
OR
$ source /etc/bash_completion

Usage examples

You need to simply press [TAB] key. The syntax is:

 
command [TAB]
command arg[TAB][TAB]
man da[TAB]

rpm usage

Type the following command (type rpm -qi ph followed by [TAB]):

$ rpm -qi ph[TAB][TAB]
php         php-cli     php-common  php-devel   php-imap

yum usage

Type the following command:

$ yum [TAB][TAB]
--assumeyes        --enableplugin     list               search
--cacheonly        --enablerepo       makecache          --setopt
check              --errorlevel       --nogpgcheck       shell
check-update       --exclude          --noplugins        --showduplicates
clean              groupinfo          --obsoletes        --skip-broken
--color            groupinstall       provides           --tolerant
--config           grouplist          --quiet            update
--debuglevel       groupremove        --randomwait       upgrade
deplist            help               reinstall          --verbose
--disableexcludes  --help             --releasever       version
--disableplugin    history            remove             --version
--disablerepo      info               repolist
distro-sync        install            resolvedep
downgrade          --installroot      --rpmverbosity

To search a package called lsof:
$ yum se[TAB] lsof
Or search and install on fly:

# yum in[TAB] ls[TAB]
lshell.noarch            lslk-debuginfo.x86_64    lsscsi-debuginfo.x86_64
lshw-gui.x86_64          lslk.x86_64              lsscsi.x86_64
lshw.x86_64              lsof-debuginfo.x86_64    lsyncd.x86_64

cryptsetup usage

Linux Unified Key Setup-on-disk-format (LUKS) allows you to encrypt whole disks and you can use cryptsetup command to mount or remount encrypted partition:
cryptsetup [TAB] luksOpen /dev/md[TAB]
Sample outputs:

Fig.01: cryptsetup on RHEL based system

A list of all commands supported by Autocomplete feature

Type the following command:
$ cd /etc/bash_completion.d $ ls
Sample outputs:

autoconf       gpg2               ntpdate           shadow
automake       gzip               open-iscsi        smartctl
bash-builtins  iconv              openssl           sqlite3
bind-utils     iftop              perl              ssh
brctl          ifupdown           pkg-config        strace
bzip2          info               pm-utils          subscription-manager
chkconfig      ipmitool           postfix           tar
configure      iproute2           procps            tcpdump
coreutils      iptables           python            util-linux
cpio           lsof               quota-tools       wireless-tools
crontab        lvm                redefine_filedir  xmllint
cryptsetup     lzma               rfkill            xmlwf
dd             make               rpm               xz
dhclient       man                rsync             yum.bash
e2fsprogs      mdadm              scl.bash          yum-utils.bash
findutils      module-init-tools  service
getent         net-tools          sh