The manpage for ssh claims:
ssh exits with the exit status of the remote command or with 255 if an error occurred.
Have you tried to look at the return value of system? 
my $status = system("/usr/bin/ssh $server \"/usr/sbin/useradd $login\"
+");

[download]

or, using qq... 

my $status = system qq(/usr/bin/ssh $server "/usr/sbin/useradd $login"
+);

[download]

In reply to Re: getting multiple return values from system() by toolic
in thread getting multiple return values from system() by handarbyte

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