2つのファイルの新旧を比較する

#!/bin/sh
#file_datecmp.sh

if [ $# -ne 2 ]; then
    echo "Usage: file_datecmp.sh file1 file2"
    exit 1
fi

[ -e "$1" ] || { echo "$1 does not exist"; exit 1; }
[ -e "$2" ] || { echo "$2 does not exist"; exit 1; }

if [ "$1" -nt "$2" ]; then
    echo "$1 is newer then $2"
elif [ "$1" -ot "$2" ]; then
    echo "$1 is older then $2"
else
    echo "$1 and $2 have exactly the same timestamp."
fi

$ ./file_datecmp.sh array.sh arith.sh
array.sh is newer then arith.sh