Getting Information from the process Module

The process module has a wealth of information about the running process and the system architecture. This information can be useful when you’re implementing applications. For example, the process.pid property gives you the process ID that you can then have your application use.

Table 9.3 lists the properties and methods that you can access from the process module and describes what they return.

Table 9.3 Methods and properties of the process module

To help you understand accessing information using the process module, the code in Listing 9.1 makes a series of calls, and it outputs the results to the console, as shown in Figure 9.1.

Listing 9.1 process_info.js: Accessing information about a process and system, using the process module

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01 var util = require('util'),
02 console.log('Current directory: ' + process.cwd());
03 console.log('Environment Settings: ' + JSON.stringify(process.env));
04 console.log('Node Args: ' + process.argv);
05 console.log('Execution Path: ' + process.execPath);
06 console.log('Execution Args: ' + JSON.stringify(process.execArgv));
07 console.log('Node Version: ' + process.version);
08 console.log('Module Versions: ' +  JSON.stringify(process.versions));
09 //console.log(process.config);
10 console.log('Process ID: ' + process.pid);
11 console.log('Process Title: ' + process.title);
12 console.log('Process Platform: ' + process.platform);
13 console.log('Process Architecture: ' + process.arch);
14 console.log('Memory Usage: ' + util.inspect(process.memoryUsage()));
15 var start = process.hrtime();
16 setTimeout(function() {
17   var delta = process.hrtime(start);
18   console.log('High-Res timer took %d seconds and %d nanoseconds',
19               delta[0], + delta[1]);
20   console.log('Node has been running %d seconds', process.uptime());
21 }, 1000);

Figure 9.1 Getting information about a process and system by using the process module.