ifstat script for WSL1

ifstat.py

#!/usr/bin/env python3
"""
ifstat.py — WSL1 network traffic monitor (via Windows PowerShell)

WSL1 does not report interface stats properly via ifconfig or ifstat.
This script mimics the behavior of `ifstat` by displaying per-interface
network I/O statistics (KB/s in and KB/s out) updated once per second.
It leverages a persistent PowerShell process to poll `Get-Counter` once per second.
Credits: https://github.com/fragtion
"""

import subprocess
import time
import sys
import json
import textwrap

def powershell_stream():
    ps_cmd = """
    while ($true) {
      Get-NetAdapterStatistics |
        Select-Object Name,ReceivedBytes,SentBytes |
        ConvertTo-Json -Compress;
      Start-Sleep -Seconds 1
    }
    """
    return subprocess.Popen(
        ["/mnt/c/Windows/SysWOW64/WindowsPowerShell/v1.0/powershell.exe", "-Command", ps_cmd],
        stdout=subprocess.PIPE,
        stderr=subprocess.DEVNULL,
        text=True,
        bufsize=1
    )

def parse_stats(line):
    try:
        data = json.loads(line.strip())
        if isinstance(data, dict):
            data = [data]
        stats = {}
        for entry in data:
            adapter = entry["Name"]
            received = int(entry["ReceivedBytes"])
            sent = int(entry["SentBytes"])
            stats[adapter] = (received, sent)
        return stats
    except Exception:
        return {}

proc = powershell_stream()

# wait for first sample
first_line = proc.stdout.readline()
prev_stats = parse_stats(first_line)
if not prev_stats:
    print("No adapters found or error occurred.")
    proc.terminate()
    sys.exit(1)

adapters = list(prev_stats.keys())
col_width = 10
label_width = col_width * 2

wrapped_names = []
max_lines = 0
for adapter in adapters:
    wrapped = textwrap.wrap(adapter, label_width)
    wrapped_names.append(wrapped)
    if len(wrapped) > max_lines:
        max_lines = len(wrapped)

print("Starting network traffic monitoring. Press Ctrl+C to stop.")
print("Note: First sample is baseline. Rates start from second sample.\n")

for line in range(max_lines):
    parts = []
    for wrapped in wrapped_names:
        text = wrapped[line] if line < len(wrapped) else ""
        parts.append(f"{text:^{label_width}}")
    print(" ".join(parts))

subheader = " ".join(
    f"{'KB/s in':>{col_width}}{'KB/s out':>{col_width}}" for _ in adapters
)
print(subheader)

prev_time = time.time()

try:
    for line in proc.stdout:
        current_stats = parse_stats(line)
        if not current_stats:
            continue
        current_time = time.time()
        delta_time = current_time - prev_time

        line_parts = []
        for adapter in adapters:
            if adapter in current_stats and adapter in prev_stats:
                prev_received, prev_sent = prev_stats[adapter]
                curr_received, curr_sent = current_stats[adapter]
                delta_received = (curr_received - prev_received) / delta_time / 1024
                delta_sent = (curr_sent - prev_sent) / delta_time / 1024
                rx_str = f"{delta_received:>{col_width}.2f}"
                tx_str = f"{delta_sent:>{col_width}.2f}"
                line_parts.append(f"{rx_str}{tx_str}")
            else:
                line_parts.append(f"{'0.00':>{col_width}}{'0.00':>{col_width}}")

        print(" ".join(line_parts))

        prev_stats = current_stats
        prev_time = current_time
except KeyboardInterrupt:
    proc.terminate()
    print("\nMonitoring stopped.")