nodejs Process Object

The process object in Node.js is a global object that provides information about the current Node.js process. It allows interaction with the current running process in various ways.

  1. process.argv: This property returns an array containing the command line arguments provided when the Node.js process was launched. The first element is the path to Node.js executable, the second element is the path to the JavaScript file being executed, and subsequent elements are any additional command line arguments.

  2. process.env: This property returns an object containing the user environment. It provides information about the environment in which the process is currently running, such as user settings, system paths, and other environment variables.

  3. process.pid: This property returns the process ID (PID) of the Node.js process. The PID is a unique identifier assigned to the running process by the operating system.

  4. process.cwd(): This method returns the current working directory of the Node.js process.

  5. process.on(): This method is used to set up handlers for various events that can occur during the lifetime of the Node.js process. For example, it can be used to listen for signals like SIGINT (generated by pressing Ctrl+C), SIGTERM, etc., and perform custom actions when these signals are received.

  6. process.exit(): This method is used to terminate the Node.js process with a specified exit code. By default, a successful exit has a code of 0, while non-zero codes indicate an error or abnormal termination.

  7. process.nextTick(): This method allows a function to be queued for execution on the next iteration of the event loop. It's commonly used to defer the execution of a callback function to the next tick of the event loop.

  8. process.stdout and process.stderr: These properties provide streams for writing output to the standard output (stdout) and standard error (stderr) respectively. They can be used to display information to the console or log errors and other messages.

These properties and methods of the process object offer ways to interact with and control the behavior of the Node.js process during its execution.