You are confused on several points. In Perl, a 'file' is usually a disc file which we read and write. There is no such function as 'sustr()'. There is no such thing as a variable 'XYZ'. The variable '$XYZ' is a scalar which may contain a number, a single string, or a reference. The variable '@XYZ' is an array which may contain a 'list' of almost anything. You appear to have list of SSN's. If you store them in an array, You can easily add to the end of this list with the function 'push()'. 
use strict;
use warnings;
my @XYZ = (
     '458-43-0764',
     '453-45-3214',
     '462-63-4878',
     '453-99-0002',
     '462-75-5714',
     '631-03-6456',
     '466-91-7461',
     '467-17-2570',
     '454-69-1673',
     '258-61-1036',
);
push @XYZ, '111-22-3333';
local $, = "\n"; # Separate fields in output
print @XYZ;

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Bill

In reply to Re: Add - in between number in a file by BillKSmith
in thread Add - in between number in a file by notoperlbegineer

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