Shell Programming and Scripting

I'm filling in a table of values for grades. I decided to go with reading into a hash from the files but I'm coming up with an error when printing a value that does not exist. I need to know if I can on-the-fly print a space (" ") or blank in place of the grade.

Here's what the output should look like:


Here is my error (expected) from the missing value from file (and therefore missing hash value):


Is there any way to print a blank for the missing hash value while printing to output?

Code:

foreach ( sort { lc($a) cmp lc($b) } (keys(%nameToID)) )
{
        printf "%${longChars}s  %s %5s %5s %5s %5s\n", $_, $nameToID{$_}, $idToExam1{$nameToID{$_}}, $idToExam2{$nameToID{$_}},
         $idToAsg1{$nameToID{$_}}, $idToAsg2{$nameToID{$_}};
}

Make another variable, check if it's not set, make it blank if not, print it.

Code:

$var=somethingelse;
if(!defined($var)) $var="";

printf("%s\n", $var);

I suppose you could inject blanks into your hash to give it something to find.

Oh yeah totally forgot about the defined() function. Thanks Corona!