I was trying out some suggestions for detecting an active dial-up connection with the simplest suggestion to use ipconfig. So I had: 
#!/usr/bin/perl
use warnings;
while(1) {
    open(IPCONFIG,"ipconfig|") or die "can't read from pipe $^E";
    while(<IPCONFIG>) {
        if (/IP Address/) {
            print $_;
        }
    }
sleep(10);
}

[download]
Which works fine on NT 4 but reports warnings under W98. 
C:\Pete>perl connected.pl
        IP Address. . . . . . . . . : 0.0.0.0
Warning: unable to close filehandle IPCONFIG properly.
        IP Address. . . . . . . . . : 0.0.0.0
Warning: unable to close filehandle IPCONFIG properly.
        IP Address. . . . . . . . . : 195.44.21.11

[download]
Both are running ActiveState build 613. If, instead of reading from a pipe I execute the command in backticks and put the result into a scalar the warning does not occur. Can anyone explain what is happening, and if there is anything I can do to prevent the warning.

In reply to Unable to close filehandle properly by Odud

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