FREE SCRIPTING GUIDE

Advanced Bash-Scripting Guide

Appendix M. Sample .bashrc and .bash_profile Files

The ~/.bashrc file determines the behavior of interactive shells. A good look at this file can lead to a better understanding of Bash.

Emmanuel Rouat contributed the following very elaborate .bashrc file, written for a Linux system. He welcomes reader feedback on it.

Study the file carefully, and feel free to reuse code snippets and functions from it in your own .bashrc file or even in your scripts.

Example M-1. Sample .bashrc file

# =============================================================== #
#
# PERSONAL $HOME/.bashrc FILE for bash-3.0 (or later)
# By Emmanuel Rouat [no-email]
#
# Last modified: Tue Nov 20 22:04:47 CET 2012

#  This file is normally read 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 often 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
#
#  The choice of colors was done for a shell with a dark background
#+ (white on black), and this is usually also suited for pure text-mode
#+ consoles (no X server available). If you use a white background,
#+ you'll have to do some other choices for readability.
#
#  This bashrc file is a bit overcrowded.
#  Remember, it is just just an example.
#  Tailor it to your needs.
#
# =============================================================== #

# --> Comments added by HOWTO author.

# If not running interactively, don't do anything
[ -z "$PS1" ] && return


#-------------------------------------------------------------
# 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 me - 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) - however this code seems to work in a majority
#+ of cases.
#--------------------------------------------------------------

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
#-------------------------------------------------------------

#set -o nounset     # These  two options are useful for debugging.
#set -o xtrace
alias debug="set -o nounset; set -o xtrace"

ulimit -S -c 0      # Don't want coredumps.
set -o notify
set -o noclobber
set -o ignoreeof


# 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.


#-------------------------------------------------------------
# Greeting, motd etc. ...
#-------------------------------------------------------------

# Color definitions (taken from Color Bash Prompt HowTo).
# Some colors might look different of some terminals.
# For example, I see 'Bold Red' as 'orange' on my screen,
# hence the 'Green' 'BRed' 'Red' sequence I often use in my prompt.


# Normal Colors
Black='\e[0;30m'        # Black
Red='\e[0;31m'          # Red
Green='\e[0;32m'        # Green
Yellow='\e[0;33m'       # Yellow
Blue='\e[0;34m'         # Blue
Purple='\e[0;35m'       # Purple
Cyan='\e[0;36m'         # Cyan
White='\e[0;37m'        # White

# Bold
BBlack='\e[1;30m'       # Black
BRed='\e[1;31m'         # Red
BGreen='\e[1;32m'       # Green
BYellow='\e[1;33m'      # Yellow
BBlue='\e[1;34m'        # Blue
BPurple='\e[1;35m'      # Purple
BCyan='\e[1;36m'        # Cyan
BWhite='\e[1;37m'       # White

# Background
On_Black='\e[40m'       # Black
On_Red='\e[41m'         # Red
On_Green='\e[42m'       # Green
On_Yellow='\e[43m'      # Yellow
On_Blue='\e[44m'        # Blue
On_Purple='\e[45m'      # Purple
On_Cyan='\e[46m'        # Cyan
On_White='\e[47m'       # White

NC="\e[m"               # Color Reset


ALERT=${BWhite}${On_Red} # Bold White on red background



echo -e "${BCyan}This is BASH ${BRed}${BASH_VERSION%.*}${BCyan}\
- DISPLAY on ${BRed}$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 "${BRed}Hasta la vista, baby${NC}"
}
trap _exit EXIT

#-------------------------------------------------------------
# Shell Prompt - for many examples, see:
#       http://www.debian-administration.org/articles/205
#       http://www.askapache.com/linux/bash-power-prompt.html
#       http://tldp.org/HOWTO/Bash-Prompt-HOWTO
#       https://github.com/nojhan/liquidprompt
#-------------------------------------------------------------
# Current Format: [TIME USER@HOST PWD] >
# TIME:
#    Green     == machine load is low
#    Orange    == machine load is medium
#    Red       == machine load is high
#    ALERT     == machine load is very high
# USER:
#    Cyan      == normal user
#    Orange    == SU to user
#    Red       == root
# HOST:
#    Cyan      == local session
#    Green     == secured remote connection (via ssh)
#    Red       == unsecured remote connection
# PWD:
#    Green     == more than 10% free disk space
#    Orange    == less than 10% free disk space
#    ALERT     == less than 5% free disk space
#    Red       == current user does not have write privileges
#    Cyan      == current filesystem is size zero (like /proc)
# >:
#    White     == no background or suspended jobs in this shell
#    Cyan      == at least one background job in this shell
#    Orange    == at least one suspended job in this shell
#
#    Command is added to the history file each time you hit enter,
#    so it's available to all shells (using 'history -a').


# Test connection type:
if [ -n "${SSH_CONNECTION}" ]; then
    CNX=${Green}        # Connected on remote machine, via ssh (good).
elif [[ "${DISPLAY%%:0*}" != "" ]]; then
    CNX=${ALERT}        # Connected on remote machine, not via ssh (bad).
else
    CNX=${BCyan}        # Connected on local machine.
fi

# Test user type:
if [[ ${USER} == "root" ]]; then
    SU=${Red}           # User is root.
elif [[ ${USER} != $(logname) ]]; then
    SU=${BRed}          # User is not login user.
else
    SU=${BCyan}         # User is normal (well ... most of us are).
fi



NCPU=$(grep -c 'processor' /proc/cpuinfo)    # Number of CPUs
SLOAD=$(( 100*${NCPU} ))        # Small load
MLOAD=$(( 200*${NCPU} ))        # Medium load
XLOAD=$(( 400*${NCPU} ))        # Xlarge load

# Returns system load as percentage, i.e., '40' rather than '0.40)'.
function load()
{
    local SYSLOAD=$(cut -d " " -f1 /proc/loadavg | tr -d '.')
    # System load of the current host.
    echo $((10#$SYSLOAD))       # Convert to decimal.
}

# Returns a color indicating system load.
function load_color()
{
    local SYSLOAD=$(load)
    if [ ${SYSLOAD} -gt ${XLOAD} ]; then
        echo -en ${ALERT}
    elif [ ${SYSLOAD} -gt ${MLOAD} ]; then
        echo -en ${Red}
    elif [ ${SYSLOAD} -gt ${SLOAD} ]; then
        echo -en ${BRed}
    else
        echo -en ${Green}
    fi
}

# Returns a color according to free disk space in $PWD.
function disk_color()
{
    if [ ! -w "${PWD}" ] ; then
        echo -en ${Red}
        # No 'write' privilege in the current directory.
    elif [ -s "${PWD}" ] ; then
        local used=$(command df -P "$PWD" |
                   awk 'END {print $5} {sub(/%/,"")}')
        if [ ${used} -gt 95 ]; then
            echo -en ${ALERT}           # Disk almost full (>95%).
        elif [ ${used} -gt 90 ]; then
            echo -en ${BRed}            # Free disk space almost gone.
        else
            echo -en ${Green}           # Free disk space is ok.
        fi
    else
        echo -en ${Cyan}
        # Current directory is size '0' (like /proc, /sys etc).
    fi
}

# Returns a color according to running/suspended jobs.
function job_color()
{
    if [ $(jobs -s | wc -l) -gt "0" ]; then
        echo -en ${BRed}
    elif [ $(jobs -r | wc -l) -gt "0" ] ; then
        echo -en ${BCyan}
    fi
}

# Adds some text in the terminal frame (if applicable).


# Now we construct the prompt.
PROMPT_COMMAND="history -a"
case ${TERM} in
  *term | rxvt | linux)
        PS1="\[\$(load_color)\][\A\[${NC}\] "
        # Time of day (with load info):
        PS1="\[\$(load_color)\][\A\[${NC}\] "
        # User@Host (with connection type info):
        PS1=${PS1}"\[${SU}\]\u\[${NC}\]@\[${CNX}\]\h\[${NC}\] "
        # PWD (with 'disk space' info):
        PS1=${PS1}"\[\$(disk_color)\]\W]\[${NC}\] "
        # Prompt (with 'job' info):
        PS1=${PS1}"\[\$(job_color)\]>\[${NC}\] "
        # Set title of current xterm:
        PS1=${PS1}"\[\e]0;[\u@\h] \w\a\]"
        ;;
    *)
        PS1="(\A \u@\h \W) > " # --> PS1="(\A \u@\h \w) > "
                               # --> Shows full pathname of current dir.
        ;;
esac



export TIMEFORMAT=$'\nreal %3R\tuser %3U\tsys %3S\tpcpu %P\n'
export HISTIGNORE="&:bg:fg:ll:h"
export HISTTIMEFORMAT="$(echo -e ${BCyan})[%d/%m %H:%M:%S]$(echo -e ${NC}) "
export HISTCONTROL=ignoredups
export HOSTFILE=$HOME/.hosts    # Put a list of remote hosts in ~/.hosts


#============================================================
#
#  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.
#
#============================================================

#-------------------
# 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 ..'

# Pretty-print of some PATH variables:
alias path='echo -e ${PATH//:/\\n}'
alias libpath='echo -e ${LD_LIBRARY_PATH//:/\\n}'


alias du='du -kh'    # Makes a more readable output.
alias df='df -kTh'

#-------------------------------------------------------------
# The 'ls' family (this assumes you use a recent GNU ls).
#-------------------------------------------------------------
# Add colors for filetype and  human-readable sizes by default on 'ls':
alias ls='ls -h --color'
alias lx='ls -lXB'         #  Sort by extension.
alias lk='ls -lSr'         #  Sort by size, biggest last.
alias lt='ls -ltr'         #  Sort by date, most recent last.
alias lc='ls -ltcr'        #  Sort by/show change time,most recent last.
alias lu='ls -ltur'        #  Sort by/show access time,most recent last.

# The ubiquitous 'll': directories first, with alphanumeric sorting:
alias ll="ls -lv --group-directories-first"
alias lm='ll |more'        #  Pipe through 'more'
alias lr='ll -R'           #  Recursive ls.
alias la='ll -A'           #  Show hidden files.
alias tree='tree -Csuh'    #  Nice alternative to 'recursive ls' ...


#-------------------------------------------------------------
# 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:-...'

# LESS man page colors (makes Man pages more readable).
export LESS_TERMCAP_mb=$'\E[01;31m'
export LESS_TERMCAP_md=$'\E[01;31m'
export LESS_TERMCAP_me=$'\E[0m'
export LESS_TERMCAP_se=$'\E[0m'
export LESS_TERMCAP_so=$'\E[01;44;33m'
export LESS_TERMCAP_ue=$'\E[0m'
export LESS_TERMCAP_us=$'\E[01;32m'


#-------------------------------------------------------------
# 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
#-------------------------------------------------------------

# Adds some text in the terminal frame (if applicable).

function xtitle()
{
    case "$TERM" in
    *term* | rxvt)
        echo -en  "\e]0;$*\a" ;;
    *)  ;;
    esac
}


# Aliases that use xtitle
alias top='xtitle Processes on $HOST && top'
alias make='xtitle Making $(basename $PWD) ; make'

# .. and functions
function man()
{
    for i ; do
        xtitle The $(basename $1|tr -d .[:digit:]) manual
        command man -a "$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 & strings 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 mycase=""
    local usage="fstr: find string in files.
Usage: fstr [-i] \"pattern\" [\"filename pattern\"] "
    while getopts :it opt
    do
        case "$opt" in
           i) mycase="-i " ;;
           *) echo "$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 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
}


# Creates an archive (*.tar.gz) from given directory.
function maketar() { tar cvzf "${1%%/}.tar.gz"  "${1%%/}/"; }

# Create a ZIP archive of a file or folder.
function makezip() { zip -r "${1%%/}.zip" "$1" ; }

# Make your directories and files access rights sane.
function sanitize() { chmod -R u=rwX,g=rX,o= "$@" ;}

#-------------------------------------------------------------
# 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 mydf()         # Pretty-print of 'df' output.
{                       # Inspired by 'dfc' utility.
    for fs ; do

        if [ ! -d $fs ]
        then
          echo -e $fs" :No such file or directory" ; continue
        fi

        local info=( $(command df -P $fs | awk 'END{ print $2,$3,$5 }') )
        local free=( $(command df -Pkh $fs | awk 'END{ print $4 }') )
        local nbstars=$(( 20 * ${info[1]} / ${info[0]} ))
        local out="["
        for ((j=0;j<20;j++)); do
            if [ ${j} -lt ${nbstars} ]; then
               out=$out"*"
            else
               out=$out"-"
            fi
        done
        out=${info[2]}" "$out"] ("$free" free on "$fs")"
        echo -e $out
    done
}


function my_ip() # Get IP adress on ethernet.
{
    MY_IP=$(/sbin/ifconfig eth0 | awk '/inet/ { print $2 } ' |
      sed -e s/addr://)
    echo ${MY_IP:-"Not connected"}
}

function ii()   # Get current host related info.
{
    echo -e "\nYou are logged on ${BRed}$HOST"
    echo -e "\n${BRed}Additionnal information:$NC " ; uname -a
    echo -e "\n${BRed}Users logged on:$NC " ; w -hs |
             cut -d " " -f1 | sort | uniq
    echo -e "\n${BRed}Current date :$NC " ; date
    echo -e "\n${BRed}Machine stats :$NC " ; uptime
    echo -e "\n${BRed}Memory stats :$NC " ; free
    echo -e "\n${BRed}Diskspace :$NC " ; mydf / $HOME
    echo -e "\n${BRed}Local IP Address :$NC" ; my_ip
    echo -e "\n${BRed}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 SECTION
#  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 then 3.0 for some features.
#
#  Note that most linux distributions now provide many completions
# 'out of the box' - however, you might need to make your own one day,
#  so I kept those here as examples.
#=========================================================================

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.

complete -A hostname   rsh rcp telnet rlogin 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=( $( 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



# Local Variables:
# mode:shell-script
# sh-shell:bash
# End:

And, here is a snippet from Andrzej Szelachowski's instructive .bash_profile file.

Example M-2. .bash_profile file

# 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.