Le fichier ~/.bashrc détermine le comportement des shells interactifs. Une étude de ce fichier peut amener une meilleure compréhension de Bash.
Emmanuel Rouat a fourni le fichier .bashrc suivant, très élaboré et écrit pour un système Linux. Il accepte volontiers des commentaires des lecteurs.
Étudiez le fichier avec attention et n'hésitez pas à réutiliser certaines parties du code pour votre propre .bashrc, voire même dans vos scripts.
Exemple L.1. Exemple de fichier .bashrc
#============================================================= # # PERSONAL $HOME/.bashrc FILE for bash-3.0 (or later) # By Emmanuel Rouat <no-email> # # Last modified: Sun Nov 30 16:27:45 CET 2008 # This file is read (normally) by interactive shells only. # Here is the place to define your aliases, functions and # other interactive features like your prompt. # # The majority of the code here assumes you are on a GNU # system (most likely a Linux box) and is based on code found # on Usenet or internet. See for instance: # # http://tldp.org/LDP/abs/html/index.html # http://www.caliban.org/bash/ # http://www.shelldorado.com/scripts/categories.html # http://www.dotfiles.org/ # # This bashrc file is a bit overcrowded -- remember it is just # just an example. Tailor it to your needs. # # #============================================================= # --> Comments added by HOWTO author. #------------------------------------------------------------- # Source global definitions (if any) #------------------------------------------------------------- if [ -f /etc/bashrc ]; then . /etc/bashrc # --> Read /etc/bashrc, if present. fi #------------------------------------------------------------- # Automatic setting of $DISPLAY (if not set already). # This works for linux - your mileage may vary. ... # The problem is that different types of terminals give # different answers to 'who am i' (rxvt in particular can be # troublesome). # I have not found a 'universal' method yet. #------------------------------------------------------------- function get_xserver () { case $TERM in xterm ) XSERVER=$(who am i | awk '{print $NF}' | tr -d ')''(' ) # Ane-Pieter Wieringa suggests the following alternative: # I_AM=$(who am i) # SERVER=${I_AM#*(} # SERVER=${SERVER%*)} XSERVER=${XSERVER%%:*} ;; aterm | rxvt) # Find some code that works here. ... ;; esac } if [ -z ${DISPLAY:=""} ]; then get_xserver if [[ -z ${XSERVER} || ${XSERVER} == $(hostname) || \ ${XSERVER} == "unix" ]]; then DISPLAY=":0.0" # Display on local host. else DISPLAY=${XSERVER}:0.0 # Display on remote host. fi fi export DISPLAY #------------------------------------------------------------- # Some settings #------------------------------------------------------------- ulimit -S -c 0 # Don't want any coredumps. set -o notify set -o noclobber set -o ignoreeof set -o nounset #set -o xtrace # Useful for debuging. # Enable options: shopt -s cdspell shopt -s cdable_vars shopt -s checkhash shopt -s checkwinsize shopt -s sourcepath shopt -s no_empty_cmd_completion shopt -s cmdhist shopt -s histappend histreedit histverify shopt -s extglob # Necessary for programmable completion. # Disable options: shopt -u mailwarn unset MAILCHECK # Don't want my shell to warn me of incoming mail. export TIMEFORMAT=$'\nreal %3R\tuser %3U\tsys %3S\tpcpu %P\n' export HISTTIMEFORMAT="%H:%M > " export HISTIGNORE="&:bg:fg:ll:h" export HOSTFILE=$HOME/.hosts # Put list of remote hosts in ~/.hosts ... #------------------------------------------------------------- # Greeting, motd etc... #------------------------------------------------------------- # Define some colors first: red='\e[0;31m' RED='\e[1;31m' blue='\e[0;34m' BLUE='\e[1;34m' cyan='\e[0;36m' CYAN='\e[1;36m' NC='\e[0m' # No Color # --> Nice. Has the same effect as using "ansi.sys" in DOS. # Looks best on a terminal with black background..... echo -e "${CYAN}This is BASH ${RED}${BASH_VERSION%.*}\ ${CYAN} - DISPLAY on ${RED}$DISPLAY${NC}\n" date if [ -x /usr/games/fortune ]; then /usr/games/fortune -s # Makes our day a bit more fun.... :-) fi function _exit() # Function to run upon exit of shell. { echo -e "${RED}Hasta la vista, baby${NC}" } trap _exit EXIT #------------------------------------------------------------- # Shell Prompt #------------------------------------------------------------- if [[ "${DISPLAY%%:0*}" != "" ]]; then HILIT=${red} # remote machine: prompt will be partly red else HILIT=${cyan} # local machine: prompt will be partly cyan fi # --> Replace instances of \W with \w in prompt functions below #+ --> to get display of full path name. function fastprompt() { unset PROMPT_COMMAND case $TERM in *term | rxvt ) PS1="${HILIT}[\h]$NC \W > \[\033]0;\${TERM} [\u@\h] \w\007\]" ;; linux ) PS1="${HILIT}[\h]$NC \W > " ;; *) PS1="[\h] \W > " ;; esac } _powerprompt() { LOAD=$(uptime|sed -e "s/.*: \([^,]*\).*/\1/" -e "s/ //g") } function powerprompt() { PROMPT_COMMAND=_powerprompt case $TERM in *term | rxvt ) PS1="${HILIT}[\A - \$LOAD]$NC\n[\u@\h \#] \W > \ \[\033]0;\${TERM} [\u@\h] \w\007\]" ;; linux ) PS1="${HILIT}[\A - \$LOAD]$NC\n[\u@\h \#] \W > " ;; * ) PS1="[\A - \$LOAD]\n[\u@\h \#] \W > " ;; esac } powerprompt # This is the default prompt -- might be slow. # If too slow, use fastprompt instead. ... #=============================================================== # # ALIASES AND FUNCTIONS # # Arguably, some functions defined here are quite big. # If you want to make this file smaller, these functions can # be converted into scripts and removed from here. # # Many functions were taken (almost) straight from the bash-2.04 # examples. # #=============================================================== #------------------- # Personnal Aliases #------------------- alias rm='rm -i' alias cp='cp -i' alias mv='mv -i' # -> Prevents accidentally clobbering files. alias mkdir='mkdir -p' alias h='history' alias j='jobs -l' alias which='type -a' alias ..='cd ..' alias path='echo -e ${PATH//:/\\n}' alias libpath='echo -e ${LD_LIBRARY_PATH//:/\\n}' alias print='/usr/bin/lp -o nobanner -d $LPDEST' # Assumes LPDEST is defined (default printer) alias pjet='enscript -h -G -fCourier9 -d $LPDEST' # Pretty-print using enscript alias du='du -kh' # Makes a more readable output. alias df='df -kTh' #------------------------------------------------------------- # The 'ls' family (this assumes you use a recent GNU ls) #------------------------------------------------------------- alias ll="ls -l --group-directories-first" alias ls='ls -hF --color' # add colors for filetype recognition alias la='ls -Al' # show hidden files alias lx='ls -lXB' # sort by extension alias lk='ls -lSr' # sort by size, biggest last alias lc='ls -ltcr' # sort by and show change time, most recent last alias lu='ls -ltur' # sort by and show access time, most recent last alias lt='ls -ltr' # sort by date, most recent last alias lm='ls -al |more' # pipe through 'more' alias lr='ls -lR' # recursive ls alias tree='tree -Csu' # nice alternative to 'recursive ls' # If your version of 'ls' doesn't support --group-directories-first try this: # function ll(){ ls -l "$@"| egrep "^d" ; ls -lXB "$@" 2>&-| \ # egrep -v "^d|total "; } #------------------------------------------------------------- # tailoring 'less' #------------------------------------------------------------- alias more='less' export PAGER=less export LESSCHARSET='latin1' export LESSOPEN='|/usr/bin/lesspipe.sh %s 2>&-' # Use this if lesspipe.sh exists export LESS='-i -N -w -z-4 -g -e -M -X -F -R -P%t?f%f \ :stdin .?pb%pb\%:?lbLine %lb:?bbByte %bb:-...' #------------------------------------------------------------- # spelling typos - highly personnal and keyboard-dependent :-) #------------------------------------------------------------- alias xs='cd' alias vf='cd' alias moer='more' alias moew='more' alias kk='ll' #------------------------------------------------------------- # A few fun ones #------------------------------------------------------------- function xtitle() # Adds some text in the terminal frame. { case "$TERM" in *term | rxvt) echo -n -e "\033]0;$*\007" ;; *) ;; esac } # aliases that use xtitle alias top='xtitle Processes on $HOST && top' alias make='xtitle Making $(basename $PWD) ; make' alias ncftp="xtitle ncFTP ; ncftp" # .. and functions function man() { for i ; do xtitle The $(basename $1|tr -d .[:digit:]) manual command man -F -a "$i" done } #------------------------------------------------------------- # Make the following commands run in background automatically: #------------------------------------------------------------- function te() # Wrapper around xemacs/gnuserv ... { if [ "$(gnuclient -batch -eval t 2>&-)" == "t" ]; then gnuclient -q "$@"; else ( xemacs "$@" &); fi } function soffice() { command soffice "$@" & } function firefox() { command firefox "$@" & } function xpdf() { command xpdf "$@" & } #------------------------------------------------------------- # File & string-related functions: #------------------------------------------------------------- # Find a file with a pattern in name: function ff() { find . -type f -iname '*'$*'*' -ls ; } # Find a file with pattern $1 in name and Execute $2 on it: function fe() { find . -type f -iname '*'${1:-}'*' -exec ${2:-file} {} \; ; } # Find a pattern in a set of files and highlight them: # (needs a recent version of egrep) function fstr() { OPTIND=1 local case="" local usage="fstr: find string in files. Usage: fstr [-i] \"pattern\" [\"filename pattern\"] " while getopts :it opt do case "$opt" in i) case="-i " ;; *) echo "$usage"; return;; esac done shift $(( $OPTIND - 1 )) if [ "$#" -lt 1 ]; then echo "$usage" return; fi find . -type f -name "${2:-*}" -print0 | \ xargs -0 egrep --color=always -sn ${case} "$1" 2>&- | more } function cuttail() # cut last n lines in file, 10 by default { nlines=${2:-10} sed -n -e :a -e "1,${nlines}!{P;N;D;};N;ba" $1 } function lowercase() # move filenames to lowercase { for file ; do filename=${file##*/} case "$filename" in */*) dirname==${file%/*} ;; *) dirname=.;; esac nf=$(echo $filename | tr A-Z a-z) newname="${dirname}/${nf}" if [ "$nf" != "$filename" ]; then mv "$file" "$newname" echo "lowercase: $file --> $newname" else echo "lowercase: $file not changed." fi done } function swap() # Swap 2 filenames around, if they exist { #(from Uzi's bashrc). local TMPFILE=tmp.$$ [ $# -ne 2 ] && echo "swap: 2 arguments needed" && return 1 [ ! -e $1 ] && echo "swap: $1 does not exist" && return 1 [ ! -e $2 ] && echo "swap: $2 does not exist" && return 1 mv "$1" $TMPFILE mv "$2" "$1" mv $TMPFILE "$2" } function extract() # Handy Extract Program. { if [ -f $1 ] ; then case $1 in *.tar.bz2) tar xvjf $1 ;; *.tar.gz) tar xvzf $1 ;; *.bz2) bunzip2 $1 ;; *.rar) unrar x $1 ;; *.gz) gunzip $1 ;; *.tar) tar xvf $1 ;; *.tbz2) tar xvjf $1 ;; *.tgz) tar xvzf $1 ;; *.zip) unzip $1 ;; *.Z) uncompress $1 ;; *.7z) 7z x $1 ;; *) echo "'$1' cannot be extracted via >extract<" ;; esac else echo "'$1' is not a valid file" fi } #------------------------------------------------------------- # Process/system related functions: #------------------------------------------------------------- function my_ps() { ps $@ -u $USER -o pid,%cpu,%mem,bsdtime,command ; } function pp() { my_ps f | awk '!/awk/ && $0~var' var=${1:-".*"} ; } function killps() # Kill by process name. { local pid pname sig="-TERM" # Default signal. if [ "$#" -lt 1 ] || [ "$#" -gt 2 ]; then echo "Usage: killps [-SIGNAL] pattern" return; fi if [ $# = 2 ]; then sig=$1 ; fi for pid in $(my_ps| awk '!/awk/ && $0~pat { print $1 }' pat=${!#} ) ; do pname=$(my_ps | awk '$1~var { print $5 }' var=$pid ) if ask "Kill process $pid <$pname> with signal $sig?" then kill $sig $pid fi done } function my_ip() # Get IP adresses. { MY_IP=$(/sbin/ifconfig ppp0 | awk '/inet/ { print $2 } ' | \ sed -e s/addr://) MY_ISP=$(/sbin/ifconfig ppp0 | awk '/P-t-P/ { print $3 } ' | \ sed -e s/P-t-P://) } function ii() # Get current host related info. { echo -e "\nYou are logged on ${RED}$HOST" echo -e "\nAdditionnal information:$NC " ; uname -a echo -e "\n${RED}Users logged on:$NC " ; w -h echo -e "\n${RED}Current date :$NC " ; date echo -e "\n${RED}Machine stats :$NC " ; uptime echo -e "\n${RED}Memory stats :$NC " ; free my_ip 2>&- ; echo -e "\n${RED}Local IP Address :$NC" ; echo ${MY_IP:-"Not connected"} echo -e "\n${RED}ISP Address :$NC" ; echo ${MY_ISP:-"Not connected"} echo -e "\n${RED}Open connections :$NC "; netstat -pan --inet; echo } #------------------------------------------------------------- # Misc utilities: #------------------------------------------------------------- function repeat() # Repeat n times command. { local i max max=$1; shift; for ((i=1; i <= max ; i++)); do # --> C-like syntax eval "$@"; done } function ask() # See 'killps' for example of use. { echo -n "$@" '[y/n] ' ; read ans case "$ans" in y*|Y*) return 0 ;; *) return 1 ;; esac } function corename() # Get name of app that created a corefile. { for file ; do echo -n $file : ; gdb --core=$file --batch | head -1 done } #========================================================================= # PROGRAMMABLE COMPLETION - ONLY SINCE BASH-2.04 # Most are taken from the bash 2.05 documentation and from Ian McDonald's # 'Bash completion' package (http://www.caliban.org/bash/#completion). # You will in fact need bash more recent than 3.0 for some features. #========================================================================= if [ "${BASH_VERSION%.*}" \< "3.0" ]; then echo "You will need to upgrade to version 3.0 \ for full programmable completion features." return fi shopt -s extglob # Necessary, #set +o nounset # otherwise some completions will fail. complete -A hostname rsh rcp telnet rlogin r ftp ping disk complete -A export printenv complete -A variable export local readonly unset complete -A enabled builtin complete -A alias alias unalias complete -A function function complete -A user su mail finger complete -A helptopic help # Currently, same as builtins. complete -A shopt shopt complete -A stopped -P '%' bg complete -A job -P '%' fg jobs disown complete -A directory mkdir rmdir complete -A directory -o default cd # Compression complete -f -o default -X '*.+(zip|ZIP)' zip complete -f -o default -X '!*.+(zip|ZIP)' unzip complete -f -o default -X '*.+(z|Z)' compress complete -f -o default -X '!*.+(z|Z)' uncompress complete -f -o default -X '*.+(gz|GZ)' gzip complete -f -o default -X '!*.+(gz|GZ)' gunzip complete -f -o default -X '*.+(bz2|BZ2)' bzip2 complete -f -o default -X '!*.+(bz2|BZ2)' bunzip2 complete -f -o default -X '!*.+(zip|ZIP|z|Z|gz|GZ|bz2|BZ2)' extract # Documents - Postscript,pdf,dvi..... complete -f -o default -X '!*.+(ps|PS)' gs ghostview ps2pdf ps2ascii complete -f -o default -X '!*.+(dvi|DVI)' dvips dvipdf xdvi dviselect dvitype complete -f -o default -X '!*.+(pdf|PDF)' acroread pdf2ps complete -f -o default -X \ '!*.@(@(?(e)ps|?(E)PS|pdf|PDF)?(.gz|.GZ|.bz2|.BZ2|.Z))' gv ggv complete -f -o default -X '!*.texi*' makeinfo texi2dvi texi2html texi2pdf complete -f -o default -X '!*.tex' tex latex slitex complete -f -o default -X '!*.lyx' lyx complete -f -o default -X '!*.+(htm*|HTM*)' lynx html2ps complete -f -o default -X \ '!*.+(doc|DOC|xls|XLS|ppt|PPT|sx?|SX?|csv|CSV|od?|OD?|ott|OTT)' soffice # Multimedia complete -f -o default -X \ '!*.+(gif|GIF|jp*g|JP*G|bmp|BMP|xpm|XPM|png|PNG)' xv gimp ee gqview complete -f -o default -X '!*.+(mp3|MP3)' mpg123 mpg321 complete -f -o default -X '!*.+(ogg|OGG)' ogg123 complete -f -o default -X \ '!*.@(mp[23]|MP[23]|ogg|OGG|wav|WAV|pls|m3u|xm|mod|s[3t]m|it|mtm|ult|flac)' xmms complete -f -o default -X \ '!*.@(mp?(e)g|MP?(E)G|wma|avi|AVI|asf|vob|VOB|bin|dat|vcd|\ ps|pes|fli|viv|rm|ram|yuv|mov|MOV|qt|QT|wmv|mp3|MP3|ogg|OGG|\ ogm|OGM|mp4|MP4|wav|WAV|asx|ASX)' xine complete -f -o default -X '!*.pl' perl perl5 # This is a 'universal' completion function - it works when commands have # a so-called 'long options' mode , ie: 'ls --all' instead of 'ls -a' # Needs the '-o' option of grep # (try the commented-out version if not available). # First, remove '=' from completion word separators # (this will allow completions like 'ls --color=auto' to work correctly). COMP_WORDBREAKS=${COMP_WORDBREAKS/=/} _get_longopts() { #$1 --help | sed -e '/--/!d' -e 's/.*--\([^[:space:].,]*\).*/--\1/'| \ #grep ^"$2" |sort -u ; $1 --help | grep -o -e "--[^[:space:].,]*" | grep -e "$2" |sort -u } _longopts() { local cur cur=${COMP_WORDS[COMP_CWORD]} case "${cur:-*}" in -*) ;; *) return ;; esac case "$1" in \~*) eval cmd="$1" ;; *) cmd="$1" ;; esac COMPREPLY=( $(_get_longopts ${1} ${cur} ) ) } complete -o default -F _longopts configure bash complete -o default -F _longopts wget id info a2ps ls recode _tar() { local cur ext regex tar untar COMPREPLY=() cur=${COMP_WORDS[COMP_CWORD]} # If we want an option, return the possible long options. case "$cur" in -*) COMPREPLY=( $(_get_longopts $1 $cur ) ); return 0;; esac if [ $COMP_CWORD -eq 1 ]; then COMPREPLY=( $( compgen -W 'c t x u r d A' -- $cur ) ) return 0 fi case "${COMP_WORDS[1]}" in ?(-)c*f) COMPREPLY=( $( compgen -f $cur ) ) return 0 ;; +([^Izjy])f) ext='tar' regex=$ext ;; *z*f) ext='tar.gz' regex='t\(ar\.\)\(gz\|Z\)' ;; *[Ijy]*f) ext='t?(ar.)bz?(2)' regex='t\(ar\.\)bz2\?' ;; *) COMPREPLY=( $( compgen -f $cur ) ) return 0 ;; esac if [[ "$COMP_LINE" == tar*.$ext' '* ]]; then # Complete on files in tar file. # # Get name of tar file from command line. tar=$( echo "$COMP_LINE" | \ sed -e 's|^.* \([^ ]*'$regex'\) .*$|\1|' ) # Devise how to untar and list it. untar=t${COMP_WORDS[1]//[^Izjyf]/} COMPREPLY=( $( compgen -W "$( echo $( tar $untar $tar \ 2>/dev/null ) )" -- "$cur" ) ) return 0 else # File completion on relevant files. COMPREPLY=( $( compgen -G $cur\*.$ext ) ) fi return 0 } complete -F _tar -o default tar _make() { local mdef makef makef_dir="." makef_inc gcmd cur prev i; COMPREPLY=(); cur=${COMP_WORDS[COMP_CWORD]}; prev=${COMP_WORDS[COMP_CWORD-1]}; case "$prev" in -*f) COMPREPLY=($(compgen -f $cur )); return 0 ;; esac; case "$cur" in -*) COMPREPLY=($(_get_longopts $1 $cur )); return 0 ;; esac; # make reads `GNUmakefile', then `makefile', then `Makefile' if [ -f ${makef_dir}/GNUmakefile ]; then makef=${makef_dir}/GNUmakefile elif [ -f ${makef_dir}/makefile ]; then makef=${makef_dir}/makefile elif [ -f ${makef_dir}/Makefile ]; then makef=${makef_dir}/Makefile else makef=${makef_dir}/*.mk # Local convention. fi # Before we scan for targets, see if a Makefile name was # specified with -f ... for (( i=0; i < ${#COMP_WORDS[@]}; i++ )); do if [[ ${COMP_WORDS[i]} == -f ]]; then # eval for tilde expansion eval makef=${COMP_WORDS[i+1]} break fi done [ ! -f $makef ] && return 0 # deal with included Makefiles makef_inc=$( grep -E '^-?include' $makef | \ sed -e "s,^.* ,"$makef_dir"/," ) for file in $makef_inc; do [ -f $file ] && makef="$makef $file" done # If we have a partial word to complete, restrict completions to # matches of that word. if [ -n "$cur" ]; then gcmd='grep "^$cur"' ; else gcmd=cat ; fi COMPREPLY=( $( awk -F':' '/^[a-zA-Z0-9][^$#\/\t=]*:([^=]|$)/ \ {split($1,A,/ /);for(i in A)print A[i]}' \ $makef 2>/dev/null | eval $gcmd )) } complete -F _make -X '+($*|*.[cho])' make gmake pmake _killall() { local cur prev COMPREPLY=() cur=${COMP_WORDS[COMP_CWORD]} # get a list of processes (the first sed evaluation # takes care of swapped out processes, the second # takes care of getting the basename of the process) COMPREPLY=( $( /usr/bin/ps -u $USER -o comm | \ sed -e '1,1d' -e 's#[]\[]##g' -e 's#^.*/##'| \ awk '{if ($0 ~ /^'$cur'/) print $0}' )) return 0 } complete -F _killall killall killps # A meta-command completion function for commands like sudo(8), which need to # first complete on a command, then complete according to that command's own # completion definition - currently not quite foolproof, # but still quite useful (By Ian McDonald, modified by me). _meta_comp() { local cur func cline cspec COMPREPLY=() cur=${COMP_WORDS[COMP_CWORD]} cmdline=${COMP_WORDS[@]} if [ $COMP_CWORD = 1 ]; then COMPREPLY=( $( compgen -c $cur ) ) else cmd=${COMP_WORDS[1]} # Find command. cspec=$( complete -p ${cmd} ) # Find spec of that command. # COMP_CWORD and COMP_WORDS() are not read-only, # so we can set them before handing off to regular # completion routine: # Get current command line minus initial command, cline="${COMP_LINE#$1 }" # split current command line tokens into array, COMP_WORDS=( $cline ) # set current token number to 1 less than now. COMP_CWORD=$(( $COMP_CWORD - 1 )) # If current arg is empty, add it to COMP_WORDS array # (otherwise that information will be lost). if [ -z $cur ]; then COMP_WORDS[COMP_CWORD]="" ; fi if [ "${cspec%%-F *}" != "${cspec}" ]; then # if -F then get function: func=${cspec#*-F } func=${func%% *} eval $func $cline # Evaluate it. else func=$( echo $cspec | sed -e 's/^complete//' -e 's/[^ ]*$//' ) COMPREPLY=( $( eval compgen $func $cur ) ) fi fi } complete -o default -F _meta_comp nohup \ eval exec trace truss strace sotruss gdb complete -o default -F _meta_comp command type which man nice time # Local Variables: # mode:shell-script # sh-shell:bash # End:
Et voici un extrait du fichier .bash_profile instructif d'Andrzej Szelachowski.
Exemple L.2. Fichier .bash_profile
# From Andrzej Szelachowski's ~/.bash_profile: # Note that a variable may require special treatment #+ if it will be exported. DARKGRAY='\e[1;30m' LIGHTRED='\e[1;31m' GREEN='\e[32m' YELLOW='\e[1;33m' LIGHTBLUE='\e[1;34m' NC='\e[m' PCT="\`if [[ \$EUID -eq 0 ]]; then T='$LIGHTRED' ; else T='$LIGHTBLUE'; fi; echo \$T \`" # For "literal" command substitution to be assigned to a variable, #+ use escapes and double quotes: #+ PCT="\` ... \`" . . . # Otherwise, the value of PCT variable is assigned only once, #+ when the variable is exported/read from .bash_profile, #+ and it will not change afterwards even if the user ID changes. PS1="\n$GREEN[\w] \n$DARKGRAY($PCT\t$DARKGRAY)-($PCT\u$DARKGRAY)-($PCT\! $DARKGRAY)$YELLOW-> $NC" # Escape a variables whose value changes: # if [[ \$EUID -eq 0 ]], # Otherwise the value of the EUID variable will be assigned only once, #+ as above. # When a variable is assigned, it should be called escaped: #+ echo \$T, # Otherwise the value of the T variable is taken from the moment the PCT #+ variable is exported/read from .bash_profile. # So, in this example it would be null. # When a variable's value contains a semicolon it should be strong quoted: # T='$LIGHTRED', # Otherwise, the semicolon will be interpreted as a command separator. # Variables PCT and PS1 can be merged into a new PS1 variable: PS1="\`if [[ \$EUID -eq 0 ]]; then PCT='$LIGHTRED'; else PCT='$LIGHTBLUE'; fi; echo '\n$GREEN[\w] \n$DARKGRAY('\$PCT'\t$DARKGRAY)-\ ('\$PCT'\u$DARKGRAY)-('\$PCT'\!$DARKGRAY)$YELLOW-> $NC'\`" # The trick is to use strong quoting for parts of old PS1 variable.