Adb / List Forwardings
List Forwardings
Use 'adb forward --list' to inspect active port forwarding between a host machine and Android devices for debugging.
adb forward --listadb forward --list#!/bin/bash
# List Forwardings
adb forward --listimport subprocess
# List Forwardings
# Make sure to replace <placeholders> with actual values
def run_command():
cmd = [
"adb",
"forward",
"--list"
]
try:
print(f"Executing: {' '.join(cmd)}")
subprocess.run(cmd, check=True)
except subprocess.CalledProcessError as e:
print(f"Error: {e}")
except FileNotFoundError:
print("Error: adb not found. Please install it first.")
if __name__ == "__main__":
run_command()When To Use
Execute 'adb forward --list' during multi-device debugging sessions to verify explicit port-forwarding rules, ensuring correct routing of network requests from development tools to device instances, pivotal for applications with network dependencies.
Pro Tip
The output doesn't highlight implicit rules applied by some custom ROMs. Use 'adb shell netcfg' to cross-verify active connections.
Terminal Output
Expected runtime feedback
List of forwardings:
Port Device
----------- -----------
8080 tcp:8080
8888 tcp:8888Anatomy of Output
Understanding the result
List of forward connections: Header Indicates the beginning of the forwarding list output.
serial-number tcp:local-port tcp:remote-port Format Displays the format of entries; no title rows provided.
emulator-5554 tcp:8080 tcp:8080 Example Entry Maps local port 8080 to remote port 8080 on the specified device.
Power User Variants
Optimized versions
adb -s <device-serial> forward --list Lists forwarding rules for a specific device, narrowing the results for targeted troubleshooting.
adb forward --remove-all Clears all existing port forwarding rules to resolve overlaps potentially causing conflicts between sessions.
adb forward --no-rebind tcp:8080 tcp:8080 Sets a port forwarding only if no previous forwarding exists; useful for legacy networks.
Unix Pipeline
Shell combinations
adb forward --list | grep 'tcp:8080' Combines grep to filter forwarding rules specifically for port 8080, ensuring it’s correctly mapped for a certain app.
adb forward --list | awk '{print $1}' | xargs adb -s Uses awk and xargs to iterate over specific device serials, perform a custom operation, checking health status.
Troubleshooting
Common pitfalls
adb server version (41) doesn't match this client (40); killing...
Solution: Update ADB to the matching version on both client and server to resolve compatibility issues.
failed to start daemon, error: cannot connect to daemon
Solution: Ensure no firewall or security service is blocking ADB on the host.
list-forward-protocol error EOF
Solution: Rescan USB devices using 'adb kill-server' and 'adb start-server' to refresh device connections.
Command Breakdown
What each part is doing
-
adb - Base Command
- The executable that performs this operation. Here it runs Adb before the shell applies any redirect operators.
-
--list - Command Option
- Tool-specific option used by this command invocation.
How To Run
Execution path
- Step 1
Run the command: `adb forward --list`
- Step 2
Check that the expected ports are listed in the output.
Alternative Approaches
Comparable commands in other tools
Alternative system operations tools for the same job.