JAVASCRIPT
Extract Specific Data from Log or Config Lines
Learn how to use Regex to efficiently parse and extract specific key-value pairs or data points from structured log entries or configuration files in JavaScript.
function extractLogDetails(logLine) {
const regex = /^[\[](\d{4}-\d{2}-\d{2} \d{2}:\d{2}:\d{2})][\[]([A-Z]+)][:] (.*)$/;
const match = logLine.match(regex);
if (match) {
return {
timestamp: match[1],
level: match[2],
message: match[3]
};
}
return null;
}
const logEntry = "[2023-10-27 10:30:15] [INFO]: User 'john.doe' logged in successfully.";
const details = extractLogDetails(logEntry);
console.log(details);
// Expected Output: { timestamp: '2023-10-27 10:30:15', level: 'INFO', message: "User 'john.doe' logged in successfully." }
How it works: This JavaScript function utilizes a regular expression to parse structured log lines. It defines capture groups `(...)` to extract the timestamp, log level (e.g., INFO, ERROR), and the actual message. The `match()` method returns an array containing the full match and then each captured group, allowing easy access to specific data points.