I need to keep address lines in a file at a maximum of 30 characters. I have a file with these columns:

Address_Line_1 (this is never blank)
Address_Line_2 (this could be blank)
Address_Line_3 (this could be blank)
Address_Line_4 (this is never blank)
City (this is never blank)
State (this is never blank)
Zip (this is never blank)
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I am looking to use perl to check if Address_Line_2 is greater than 30 characters.

If it is, I need to divide Address_Line_2 between Address_Line_2 and Address_Line_3, but only if Address_Line_3 is blank.

If I need to divide Address_Line_2, I would like to divide it at a point in where there is a space.

while (<INFILE>) {    
    @fields = split /\t/, $_;
    $a1 = $fields[0];
    $a2 = $fields[1];
    $a3 = $fields[2];
    $a4 = $fields[3];
    $city = $fields[4];
    $st = $fields[5];
    $zip = $fields[6];

    print OUTFILE pack ("A30", $a1);
    print OUTFILE $TAB; 
    print OUTFILE pack ("A30", $a2);
    print OUTFILE $TAB;
    print OUTFILE pack ("A30", $a3);
    print OUTFILE $TAB;
    print OUTFILE pack ("A30", $a4);
    print OUTFILE $TAB;
    print OUTFILE pack ("A16", $city);
    print OUTFILE $TAB;
    print OUTFILE pack ("A2", $st);
    print OUTFILE $TAB;
    print OUTFILE pack ("A10", $zip);
    print OUTFILE "\r\n";
}
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