类似Linux下的iftop，可以查看系统当前的网络速度：
$Host.UI.RawUI.WindowTitle = 'iftop'
$adapter = Get-NetAdapter | Where-Object { $_.Status -eq "Up" -and $_.HardwareInterface -eq $true }
if ($adapter.Count -eq 0) {
echo "没有活动网卡"
exit
}
$prev = @{}
$adapter | ForEach-Object { $prev[$_.Name] = $_ | Get-NetAdapterStatistics }
while ($true) {
sleep 1
foreach ($adpt in $adapter) {
$cur = $adpt | Get-NetAdapterStatistics
$old = $prev[$adpt.Name]
$rx = ($cur.ReceivedBytes - $old.ReceivedBytes) / 1024
$tx = ($cur.SentBytes - $old.SentBytes) / 1024
Write-Host -NoNewline "`r".PadRight(80)
Write-Host -NoNewline ("`r{0}: ↓ {1} 字节 - {2:N2} KB/s ↑ {3} 字节 - {4:N2} KB/s" -f $adpt.Name, $cur.ReceivedBytes, $rx, $cur.SentBytes, $tx)
$prev[$adpt.Name] = $cur
}
}
Doskey定义：
doskey iftop=powershell -encodedCommand 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