Use .profile in Linux to customize the shell prompt

When you have many EBS instances in a multi-nodes environment, it will be very useful to let the Linux prompt display current user ID, server name and the path location. A custom .profile saved under $HOME works for me very well. Its colors tell if you are in a Admin node or not, and if you are in a production environment or not (assume the last character of production server's name is "p").

For a Linux account, environment variable $HOME is defined by file /etc/passwd. But, if the account was created by AD (Active Directory), $HOME is defined in AD by "Home Directory".

Our EBS applMgr accounts use Korn shell which uses two startup files under $HOME, the .profile and the .kshrc. During a session start, .profile is first read once, then .kshrc (if it exists) is read by each new ksh. e.g.:

$ echo $SHELL

/bin/ksh

$ echo $0

-ksh

$ which ksh

/usr/bin/ksh

$ more .kshrc

alias ftp="print 'Reminder: Use sftp instead of \\\ftp'"

echo "This is .kshrc"

$ ksh

This is .kshrc

$ ftp

Reminder: Use sftp instead of \ftp

============= $HOME/.profile =============

PATH=/bin:/usr/bin:/usr/local/bin

export PATH

MANPATH=/usr/share/man:/usr/local/share/man

export MANPATH      # for man manual 

EDITOR=/bin/vi

export EDITOR

# ENV=$HOME/.kshrc

# export ENV

. /u02/app/EBSPROD/EBSapps.env RUN     # R12.2 env file

. /u02/app/xxx_scripts/.EBSpassenv              # password file (custom)

isMaster="no"

if [ ! -z $APPS_VERSION ] && [ ${APPS_VERSION:0:4} == "12.2" ]

then

s_status=cat $CONTEXT_FILE | grep -i s_adminserverstatus

isMaster="${s_status:60:7}"

fi

if [ $isMaster == "enabled" ]   # on admin/primary node

then

if [ echo -n ${HOSTNAME%%.*} | tail -c -1 != "p" ]   

             # last character of server name is not "p" => non-production server

then

PS1=$'

\e[0;31m$USER@${HOSTNAME%%.}[$TWO_TASK]\e[m$PWD

-->$ '  

else       # on production server: Red, and Green color on PWD

PS1=$'

\e[0;31m$USER@${HOSTNAME%%.}[$TWO_TASK]\e[m\E[32m$PWD \E[0m

-->$ '

fi

else                                          # on other node(s)

if [ echo -n ${HOSTNAME%%.*} | tail -c -1 != "p" ]   

            # on non-production server

then

PS1='

$USER@${HOSTNAME%%.}[$TWO_TASK]$PWD

-->$ '

else      # on production server

PS1=$'

$USER@${HOSTNAME%%.}[$TWO_TASK]\E[32m$PWD \E[0m

-->$ '

fi

fi

alias rm='rm -i'

stty erase ^?

umask u=rwx,g=rwx,o=rx

================ end =================

On an Admin node in production env, the prompt looks like this:

userID@server_1p[EBSPROD]/u02/app

-->$

userID@server_1p[EBSPROD]/u02/app

-->$ echo $USER

userID

userID@server_1p[EBSPROD]/u02/app

-->$ echo $TWO_TASK

EBSPROD

userID@server_1p[EBSPROD]/u02/app

-->$ cd $TWO_TASK

userID@server_1p[EBSPROD]/u02/app/EBSPROD

-->$ echo $HOME

/u02/app

userID@server_1p[EBSPROD]/u02/app/EBSPROD

-->$ ls

EBSapps.env   fs1   fs2   fs_ne