#!/bin/bash

str=0
while (( str < 100 )); do
        if [ "$(./A $str)" = "$(./B $str)" ]; then
                echo "equal"
        else
                echo "not equal while input is $str"
        fi
        let str=$str+1
done

------解决方案--------------------
#!/bin/sh
i=0
while (( $i < 1000000000 ))
do
 if [ "`echo $i|A`" != "`echo $i|B`" ]
 then
    echo "$i 结果不同"
 fi
 ((i=i+1))
done