Just check if the values are defined before printing them. I don't have a linux system so I don't know why IO::Interface (which does't compile for me on Windows/Strawberry) doesn't return a dstaddr or hwaddr.

printf "dstaddr =   %s\n", defined($if->dstaddr) ? $if->dstaddr : ''; 
+# line 15
printf "hwaddr =    %s\n", defined($if->hwaddr) ? $if->hwaddr : ''; # 
+line 16

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In reply to Re^3: Read network configuration on FreeBSD by VinsWorldcom
in thread Read network configuration on FreeBSD by josef

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