Shell Programming and Scripting

#!/bin/bash
#my array of password options
psswrd=( one two three )
#first call to open the dmg file
hdiutil attach DOCS.dmg
#here i give it a wrong input password on purpose so it enters the loop
while [ $? = 1 ]; do
	hdiutil attach DOCS.dmg
        #at this point I'm prompted with "Enter password to access "DOCS.dmg":"
        #and instead of typing the input I want to iterate through the array "psswrd" and use each of its elements in turn as an answer to the prompt
        #also i want to be able to exit the loop if i've gone through the entire array and not found the correct password
done

for let5 in a b c d e f g h i j k l m n o p q r s t u v w x y z
do
for let6 in a b c d e f g h i j k l m n o p q r s t u v w x y z
do
for let7 in a b c d e f g h i j k l m n o p q r s t u v w x y z
do
 try_pw=$let14$let5$let6$let7
 . . .
done
done
done

for let5 in {a..z}
do
for let6 in {a..z}
do
for let7 in {a..z}
do
 try_pw=$let14$let5$let6$let7
 . . .
done
done
done

if echo password | htiutil
then
        echo password worked
        break;
fi

 
(
  Insert code to generate passwords and from them generate "a script to try passwords on the remote bash",
   checking output_file for failure before generating and trying the next password,
   and exiting printing the last password on success.  N Failures might be easier to determine than success. 
  Some authenticators faill all passwords after the first three tries, so you need a fresh session to ensure your results are real.
 )|ssh2 localhost bash >output_file 2>&1

$ for i in {a..z}
> do
> echo $i
> done
{a..z}
$