bash-framework

#!/bin/bash
#
# script-name -- short desctription of what is does
# Copyright (C) 2011 Your Name <your@email.com>
#
# Version 0.0 (1970/01/01)
#
# Licensed under <insert your favorite open source licence here>
#


# Quit script on error
set -e

function usage {
    cat << EOF
Usage: $0 [OPTION]... [FILE]...
Insert description here.

Explain argument usage here.
  -a, --optiona              explain option a
  -b, --optionb              explain option b
  -c, --optionc=VAL          explain option c and VAL requirements
EOF
}

function error {
    #Do error handling here, like cleanup and suff
    rm $temp_dir
    #Or you can send an email
    mail $USER -s "Your script has crashed"
}
trap error ERR

function cleanup {
    #Do some cleanup in case script is prematurely interrupted
    echo "cleanup"
    exit 2
}
trap cleanup SIGINT SIGTERM

#Parse arguments

#If the script doesn't require mandatory argument, remove following lines.
if [ "$#" -eq 0 ] ; then
    usage
    exit 2
fi

#Describe your arguments here
PARAMS=`getopt -n $0 -o abc:h --long optiona,optionb,optionc:,help -- "$@"`
eval set -- "$PARAMS"
while true ; do
    case "$1" in
        -a|--optiona) flag_a=1; shift ;;
        -b|--optionb) flag_b=1 ; shift ;;
        -c|--optionc) some_variable=$2 ; shift 2 ;;
        -h|--help) usage ; exit 1 ;;
        --) other_variable=$2 ; shift ; break ;;
        *) usage ; exit 2 ;;
    esac
done

#Error checking
if [ -z "$other_variable" ] ; then
    echo "Error message here"
    exit 2
fi

#If you plan looping on directories and files with spaces
IFS=$(echo -en "\n\b")

#If you plan using globbing
shopt -s extglob

#If you need a temporary dir
temp_dir=$(mktemp -d)
#Then put this at the end of script
rm -r $temp_dir

#
# Snippets
#
# Most snippets comes from the Advanced Bash-Scripting Guide
# http://tldp.org/LDP/abs/html/index.html
#

#Script arguments
num_args=$#
args=$@

# Substring Extraction

${string:position}         #Extracts substring from $string at $position.
${string:position:length}  #Extracts $length characters of substring from $string at $position. 
${string: -position}       #index from the right end of the string
#If the $string parameter is "*" or "@", then this extracts a maximum of $length positional parameters, starting at $position.
#Extracts $length characters from $string starting at $position.
expr substr $string $position $length 

#Extracts $substring at beginning of $string, where $substring is a regular expression.
#regexp reference : http://tldp.org/LDP/abs/html/regexp.html#REGEXREF
expr match "$string" '\($substring\)' 

#Extracts $substring at end of $string, where $substring is a regular expression.
expr match "$string" '.*\($substring\)'
#or
expr "$string" : '.*\($substring\)'

#Deletes shortest match of $substring from front of $string.
${string#substring}        

#Deletes longest match of $substring from front of $string.
${string##substring}       

#Deletes shortest match of $substring from back of $string.
${string%substring}        

# Substring removal

#Deletes shortest match of $substring from front of $string.
${string#substring}

#Deletes longest match of $substring from front of $string.
${string##substring}

#Deletes shortest match of $substring from back of $string.
${string%substring}

#Deletes longest match of $substring from back of $string
${string%%substring}

# Substring Replacement

#Replace first match of $substring with $replacement.
${string/substring/replacement}

#Replace all matches of $substring with $replacement.
${string//substring/replacement}

#If $substring matches front end of $string, substitute $replacement for $substring.
${string/#substring/replacement}

#If $substring matches back end of $string, substitute $replacement for $substring.
${string/%substring/replacement}