# ************************************************************

# This function check, if [$number] is an integer number.

# This function return 'true' if [$number] is integer otherwise

# return 'false'.

function is_int () {

local number=$1

[ -z "$number" ] && number="x"

number=$( echo "$number" | sed 's/^[-+]*[0-9]*//g' )

if [ -z "$number" ]; then true; else false; fi

}

# sample function call

if ! is_int "$1" ; then

	echo "\$1 is no integer number!"; exit 1

fi