+sub checkcommandversion
+{
+my($class,$command,$version)=@_;
+
+ local *F;
+ do { open F,$_ or confess "Open $_: $!"; } for ("$command --version|");
+ local $/;
+ undef $/;
+ my $command_out=<F>;
+ close F;
+ my $command_version=($command_out=~m#([\d.]+)#)[0];
+ confess "$command(1) version not found in its output" if !$command_version;
+ confess "'$command' version $version or higher required"
+ # Do not take 3rd+ numbers as it would not be a number
+ if ($command_version=~/^(\d+[.]\d+)/)[0]<$version;
+}
+