readLine.md

readLine(filePath, start, end)

Asynchronously reads specific lines from a file, returning only the requested range. The start and end parameters can be line numbers or boolean flags (true for full range). Useful for partial file reads without loading the entire file into memory.

Alias: readLine()

Parameters:

• filePath <string>
• start <number>
• end <number>
• Returns: Promise<any>

Example

const fs = require('fsmate');

// If true|null|undefined `start` will set start of line
const start = 3;

// If true|null|undefined `end` will set end of line
const end = 50;

// With Promises:
fs.readLine('multiline.txt', start, end)
.then((lines) => {
  console.log(lines);
}).catch(err => {
  console.log(err);
});

// With async/await:
async function readLine(filePath, start, end) {
  try {
    const lines = await fs.readLine(filePath, start, end);
    console.log(lines);
  } catch(err) {
    console.log(err);
  }
}

readLine('your-file.txt', start, end);

For the synchronous version, see: readLineSync