Not sure how much of it is definable...
It is all tied to /etc/environment, and login.cfg....and
The /etc/security/login.cfg file is an ASCII file that contains stanzas of configuration information for login and user authentication. Each stanza has a name, followed by a : (colon), that defines its purpose. Attributes are in the form Attribute=Value. Each attribute ends with a new-line character, and each stanza ends with an additional new-line character.
/dev/tty0:
sak_enabled = true
herald = "login to tty0:"
port:
sak_enabled = false
herald = "login:"
* comma-seperated pathnames
aliases =
================.
Port stanzas define the login characteristics of ports and are named with the full path name of the port. Each port should have its own separate stanza. Each stanza has the following attributes:
herald Defines the login message printed when the getty process opens the port. The default herald is the login prompt. The value is a character string.
herald2 Defines the login message printed after a failed login attempt. The default herald is the login prompt. The value is a character string.
----------------------
check .env
.env File
A fourth file that the operating system uses at login time is the .env file, if your .profile has the following line: export ENV=$HOME/.env
The .env file enables you to customize your individual working environment variables. Because the .env file is hidden, use the li -a command to list it. The .env file contains the individual user environment variables that override the variables set in the /etc/environment file. You can tailor your environment variables as desired by modifying your .env file. The following example shows a typical .env file:
export myid=`id | sed -n -e 's/).*$//' -e 's/^.*(//p'` bold=`tput smso` norm=`tput rmso`
#set prompt: login & system name (reverse video) & path (normal)
if [ $myid = root ]
then typeset -x PSCH='${bold}#:${norm}\${PWD}> '
PS1="${bold}#:${norm}\${PWD}> "
else typeset -x PSCH='>'
PS1="${bold}$LOGNAME@$UNAME:${norm}\${PWD}> "
PS2=">"
PS3="#?"
fi
export PS1 PS2 PS3
#setup my command aliases
alias ls="/bin/ls -CF" d="/bin/ls -Fal | pg" rm="/bin/rm -i" up="cd .."
Note: Your shell uses three prompt variables:
PS1 Prompt used as the normal system prompt.
PS2 Prompt used when the shell expects more input.
PS3 Prompt used when you have root authority.
Sorry...but hope it helps #-)