how to use the readsync function from the fs-extra library in typescript

To use the readSync function from fs-extra library in TypeScript, you first need to import the library using the import statement as shown below:

index.ts
import * as fs from 'fs-extra';
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fs-extra is an npm package that extends the Node.js fs module with promises and other useful functions.

Once you have imported the fs-extra library, you can use the readSync function to read the contents of a file synchronously. The syntax for the readSync function is shown below:

index.ts
fs.readSync(fd: number, buffer: Buffer, offset: number, length: number, position: number): number;
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Here, fd is the file descriptor, buffer is the buffer to read the data into, offset is the offset in the buffer to start writing at, length is the number of bytes to read, and position is the offset from the beginning of the file where to begin reading.

Below is an example of how to use the readSync function to read the contents of a file:

index.ts
import * as fs from 'fs-extra';

const filePath: string = 'path/to/file';
const fileDescriptor: number = fs.openSync(filePath, 'r');
const fileSize: number = fs.statSync(filePath).size;
const buffer: Buffer = Buffer.alloc(fileSize);

try {
  const bytesRead: number = fs.readSync(fileDescriptor, buffer, 0, fileSize, 0);
  console.log(`Read ${bytesRead} bytes from file`);
  console.log(buffer.toString());
} catch(err) {
  console.error(err);
} finally {
  fs.closeSync(fileDescriptor);
}
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Here, filePath is the path to the file that you want to read. First, we open the file using the openSync function and obtain the file descriptor. Then, we get the size of the file using the statSync function and allocate a buffer of that size using the Buffer.alloc method.

We then try to read the contents of the file using the readSync function and log the number of bytes read and the content of the buffer to the console. In case of an error, we catch and log the error. Finally, we close the file using the closeSync function.