A simple profile to define a custom Bash prompt. Should be put in `/etc/profile.d/` (to be applied to all users), or sourced from your personal `.bashrc` file.

bash_prompt.sh

# Exit if non-interactive
[[ -z "$PS1" ]] && return

_colors=false

if [[ -x /usr/bin/tput ]] && tput setaf 1 >&/dev/null; then
    # tput is executable, and it doesn't fail when trying to set the foreground color
    _colors=true
else
    case "$TERM" in
        xterm-color|*-256color) _colors=true
    esac
fi

if $_colors; then
    PS1='[\[\e[32m\]\u@\h \[\e[34m\]\w\[\e[0m\]]\$ '
else
    PS1='[\u@\h \w]\$ '
fi
unset _colors

example_prompts.md

Example Prompts

See man bash and search for "PROMPTING".

Also useful, is a reference to ANSI escape codes.

# Simple prompt

# [user@host ~/working/dir]$

# Color
PS1='[\[\e[32m\]\u@\h \[\e[34m\]\w\[\e[0m\]]\$ '
#     ^^^^^^^^^^      ^^^^^^^^^^  ^^^^^^^^^
#     + Green         + Blue      + Reset
# No color
PS1='[\u@\h \w]\$ '

# Multi-line prompt

# $[user@host ~/working/dir]
# >

# Color
PS1='\$[\[\e[32m\]\u@\h \[\e[34m\]\w\[\e[0m\]]\n> '
#       ^^^^^^^^^^      ^^^^^^^^^^  ^^^^^^^^^
#       + Green         + Blue      + Reset
# No color
PS1='\$[\u@\h \w]\n> '

# Color prompt based on last exit code (only the ">" is colored)

# ~/working/dir>

PS1='\w$([[ "$?" = "0" ]] && echo -e "\033[32m" || echo -e "\033[31m")>\[\e[0m\] '
#                                     ^^^^^^^^              ^^^^^^^^   ^^^^^^^^^
#                                     + Green               + Red      + Reset

git_prompt.sh

# Set default bash prompt, with a git info section. To be put in /etc/profile.d/

# Return if:
test -z "$PS1" && return # not interactive
test "$(basename $SHELL)" != "bash" && return # not in bash
test "$UID" = "0" && return # user is root

# Only show the last two directories
PROMPT_DIRTRIM=2

# NOTE: Location of git-prompt.sh may be different depending on distribution
# You can find the actual file here: https://github.com/git/git/blob/master/contrib/completion/git-prompt.sh
if [[ -f "/usr/share/git-core/contrib/completion/git-prompt.sh" ]]; then
    source /usr/share/git-core/contrib/completion/git-prompt.sh
    git_info='$(GIT_PS1_SHOWDIRTYSTATE=1 GIT_PS1_SHOWUNTRACKEDFILES=1 GIT_PS1_SHOWUPSTREAM=1 __git_ps1)'
else
    git_info=''
fi

if test -x /usr/bin/tput && tput setaf 1 >&/dev/null; then
    # `tput` is executable and setting the forground color was successful
    # Colors are supported
    PS1='[\[\e[92m\]\u@\h\[\e[0m\] \[\e[94m\]\w\[\e[33m\]'$git_info'\[\e[0m\]]\$ '
else
    # Colors are not supported
    PS1='[\u@\h \w'$git_info']\$ '
fi

unset git_info

You can also just run the PS1=... lines directly in your terminal to get a preview of what they look like.

bash-5.1$ PS1='\$[\[\e[32m\]\u@\h \[\e[34m\]\w\[\e[0m\]]\n> '

$[user@host ~/working/dir]
> echo "wow! so cool!"