Shell Programming and Scripting

Either that eval serves no purpose or that echo is unintended, but both of them together result in a pointlessly convoluted printing statement that is vulnerable to shell metacharacters.

echo "letter$x=${mystr:$((x-1)):1}" accomplishes the same thing in a safe, simple manner.

Anyone not using linux may find that their system does not have seq, a non-standard gnu tool. Also, the use of echo can be problematic. Aside from the lack of portability (not all echoes support the same options), if the value of the parameter expansion begins with a dash, it can cause problems. printf is a superior tool when dealing with unknown data.

To simply print out the letters one per line:

Code:

w=$word
while [ "$w" ]; do
    printf %c\\n "$w"
    w=${w#?}
done

To assign each letter to a variable whose name ends with an incrementing number (starting with 1):

Code:

w=$word i=0
while [ "$w" ]; do
    eval "letter$((i+=1))=\${w%\$w{#?}}"
    w=${w#?}
done

Regards,
Alister