Shell Programming and Scripting

Hi, coding a simple program to compare an entered number to a randomly generated one. The number of digits are restricted so I'm just trying to figure out how to refer to the index value in a string and then compare it to the variable I want. I don't know if bash automatically indexes strings, so if I'm confusing anybody sorry.

I am not sure what you mean by 'index value'.

Like, in the string "apple" index value 0 is "a" while index value 1 is "p", etc.

It works ${VAR:offset:length}

Code:

$ VAR="asdf"
$ echo "${VAR:0:1}"

a

$ echo "${VAR:1:2}"

sd

$

Well thats almost there, selecting the first index works but I can't seem to select the second, third, and fourth indexes. I'd like to select the indexes individually.

The purpose being that I have 4 single digit numbers randomly selected, and I want to read input from the user comparing the digits individually, then echoing a statement saying that "this number is correct" etc depending on which one is right. I can do all that I just can't figure out how to individually refer to each number in the string inputted from the user.

First index is ${VAR:0:1}
Second index is ${VAR:1:1}
Third index is ${VAR:2:1}
etc.

How about

Code:

${VAR:0:1}
${VAR:1:1}
${VAR:2:1}
${VAR:3:1}

?