监听 LinuxOS 网卡的实时 IO

下面这个命令会自动识别要监听的网卡，然后启动监听。

IF=$(ip route | awk '/^default/{print $5; exit}'); echo "Monitoring $IF"; RX0=$(awk -v i="$IF:" '$1==i{print $2}' /proc/net/dev); TX0=$(awk -v i="$IF:" '$1==i{print $10}' /proc/net/dev); while sleep 1; do RX1=$(awk -v i="$IF:" '$1==i{print $2}' /proc/net/dev); TX1=$(awk -v i="$IF:" '$1==i{print $10}' /proc/net/dev); awk -v rx=$((RX1-RX0)) -v tx=$((TX1-TX0)) 'BEGIN{printf "↓ %7.2f MB/s  %7.2f Mbps    ↑ %7.2f MB/s  %7.2f Mbps\n",rx/1048576,rx*8/1000000,tx/1048576,tx*8/1000000}'; RX0=$RX1; TX0=$TX1; done

最后输出可能像是这样：

↓   12.08 MB/s  101.33 Mbps    ↑    0.25 MB/s    2.13 Mbps
↓   12.12 MB/s  101.63 Mbps    ↑    0.25 MB/s    2.12 Mbps
↓   12.06 MB/s  101.15 Mbps    ↑    0.25 MB/s    2.11 Mbps
↓   11.92 MB/s   99.98 Mbps    ↑    0.23 MB/s    1.90 Mbps
↓   12.05 MB/s  101.08 Mbps    ↑    0.23 MB/s    1.94 Mbps
↓   11.21 MB/s   94.01 Mbps    ↑    0.24 MB/s    2.04 Mbps
↓   12.12 MB/s  101.70 Mbps    ↑    0.30 MB/s    2.52 Mbps
↓   12.07 MB/s  101.24 Mbps    ↑    0.25 MB/s    2.12 Mbps
↓   12.06 MB/s  101.19 Mbps    ↑    0.25 MB/s    2.13 Mbps
↓   12.06 MB/s  101.14 Mbps    ↑    0.26 MB/s    2.15 Mbps

前面的是下载速度，后面的是上传速度。