#!/bin/bash

# bash shell to illustrate numeric comparisons
a=$1

###############################################################
# example 1:  testing number:  a > 0
# Bourne shell style
if [ $a -gt 0 ]; then
   echo positive
fi 

# Korn shell style
if (( $a > 0 )); then
   echo positive
fi 


###############################################################
# example 2:  testing if a <= 0
# Bourne shell style
if [ $a -le 0 ]; then
   echo non-positive
else 
   echo positive
fi 

# Korn shell style
if (( $a <= 0 )); then
   echo non-positive
else 
   echo positive
fi 


###############################################################
# example 3:  testing number: a < 0 and if a = 0
# Bourne shell style
if [ $a -lt 0 ]; then
   echo negative
elif [ $a -eq 0 ]; then
   echo zero
else 
   echo positive
fi 

# Korn shell style
if (( $a <= 0 )); then
   echo non-positive
elif (( $a == 0 )); then
   echo zero
else 
   echo positive
fi 


###############################################################
# example 4: testing if number a between 0 and 10, inclusive
if [ 0 -le $a  -a $a -le 10 ]; then
   echo between 0 and 10
else
   echo not between 0 and 10
fi

# Korn shell style
if (( (0 <= $a) && ($a <= 10) )); then
   echo between 0 and 10
else
   echo not between 0 and 10
fi