Question

I am writing a script that takes a 3-digit number and checks if they are unique and produces files with each digit, for example if I run “myscript 123” it will generate three files: file1, file2, and file3 BUT if I ran “my script 121” it will generate file1 and file2

I need help to look at the argument and compare each digit, could anyone give me a hand?

This is what I have written so far:

if [ $1 -gt 99 ] && [ $1 -lt 1000 ]
then
   echo "Your three digit number: $1"
else
   echo "please restart and enter a 3-digit number"
   exit
fi

Answer 1

My biggest challenge though is to check $1 and see what each digit is, I am clueless

There are several ways to retrieve each characted from a string. For example, you can split them up into an array with the help of fold:

$ IN="123"
$ DIGITS=($(echo $IN | fold -w1))
$ echo ${DIGITS[0]}
1
$ echo ${DIGITS[1]}
2

Or you can use variable substring extraction (see docs):

$ IN="123"
$ echo ${IN:0:1}
1
$ echo ${IN:1:1}
2

Or, you can use let to perform basic modulo operations:

$ IN="123"
$ let A="IN % 10"  # get last digit (3rd)
$ ((IN /= 10))     # divide by 10 (which discards last digit)
$ let B="IN % 10"  # get last digit (2nd)
$ ((IN /= 10))     # divide by 10 (which discards last digit)
$ let C="IN % 10"  # get last digit (1st)
$ echo $A
3
$ echo $B
2
$ echo $C
1