script-to-terminate-processes-by-port.md

Script to terminate running tasks on a port

Prerequisites

• sudo privileges for executing commands as root

Setup

1. Save the script: Save the provided script to a file, for example, terminate_process_on_port.sh.

   #!/usr/bin/env bash
   
   # Prompt for sudo privileges at the beginning of the script
   if [ "$EUID" -ne 0 ]; then
       sudo "$0" "$@"
       exit $?
   fi
   
   # Check if port number is provided as argument
   if [ $# -ne 1 ]; then
       echo "Usage: $0 <port>"
       exit 1
   fi
   
   port=$1
   
   # Check if any process is running on the specified port
   if lsof -i :$port >/dev/null 2>&1; then
       # Get the PID(s) of the process(es) running on the port
       pids=$(lsof -t -i :$port)
   
       # Attempt to terminate the processes running on the specified port
       terminate_task() {
           local pid=$1
           local exec_name=$(ps -p $pid -o comm=)
           local process_name=$(ps -p $pid -o args=)
           
           kill $pid
           
           # Check if the process is still running after sending SIGTERM
           sleep 3
           if ps -p $pid >/dev/null; then
               kill -9 $pid
               echo "Process ($pid) - $exec_name ($process_name) did not terminate after SIGTERM and was forcefully killed with SIGKILL."
           else
               echo "Process ($pid) - $exec_name ($process_name) terminated successfully."
           fi
       }
   
       for pid in $pids; do
           terminate_task $pid
       done
   else
       echo "No processes found running on port $port."
   fi

2. Set execute permissions: Make the script executable using the command:

   chmod +x terminate_process_on_port.sh

Optionals

• Add alias

  Be sure to change the /path/to/terminate_process_on_port.sh with actual path.

  • For Bash

    echo "alias freeport='/path/to/terminate_process_on_port.sh'" >> ~/.bashrc

    source ~/.bashrc

  • For Zsh

    echo "alias freeport='/path/to/terminate_process_on_port.sh'" >> ~/.zshrc

    source ~/.zshrc

  • For Fish

    echo "alias freeport '/path/to/terminate_process_on_port.sh'" >> ~/.config/fish/config.fish

    source ~/.config/fish/config.fish

Or

• Add to path

  Move the script to local bin then add that path to env PATH.

  mkdir -p ~/.local/bin
  mv ~/terminate_process_on_port.sh ~/.local/bin/freeport

  • For Bash

    echo 'export PATH="$HOME/.local/bin:$PATH"' >> ~/.bashrc

    source ~/.bashrc

  • For Zsh

    echo 'export PATH="$HOME/.local/bin:$PATH"' >> ~/.zshrc

    source ~/.zshrc

  • For Fish

    echo 'set -Ux fish_user_paths $HOME/.local/bin $fish_user_paths' >> ~/.config/fish/config.fish

    source ~/.config/fish/config.fish

Usage

Run the script with the following command:

./terminate_process_on_port.sh <port>

Replace <port> with the port number where you want to terminate the process running on.

Run the following command if followed through any of the optional setup:

freeport <port>

Example:

To terminate a process running on port 8080, run:

./terminate_process_on_port.sh 8080

or

freeport 8080