Shell Programming and Scripting

#!/bin/bash
if [ $# -eq 0 ] ; then
    echo "enter <file> <time>"
exit 1
fi

if [ ! -e $1 ] ; then
    echo " please enter an existing file"
exit 2
fi

if [ "$2" = "" ] ; then
    echo " no argument 2"
exit 3
fi

if [ $2 -lt 10 ] ; then 
    echo " please enter a number higher than 10"
exit 4
fi

while [ $2 -ge 10 ] ; do
if [ $1 -nt ] ; then
    sleep $2
    mail $LOGNAME
else
    echo "file unchanged"
fi
done
exit 0

#!/bin/bash

if [[ $# != 2 ]]; then
   echo "enter <file> <time>"
   exit 1
fi

if [[ ! -e $1 ]]; then
   echo "please enter an existing file"
   exit 2
fi

if [[ $2 < 10 ]]; then
   echo "please enter a number higher than 10"
   exit 4
fi

TFILE=/tmp/touchme.$$
touch $TFILE

i=$2
while (( i >= 10 )) ; do
    if [[ $1 -nt $TFILE ]]; then
        echo "file changed"
    else
        echo "file unchanged"
    fi
    sleep $i
    (( --i ))
done

rm $TFILE

exit  0