Node.js fs.writeSync() Method

The file system module or fs module is an inbuilt module in Node js which is used to work with files on the computer. The functions of the module can be used by importing the fs module. The fs module can be included in the program by using the fs.writeSync() function of the filesystem module is the synchronous version of the write() method. It can be used for writing text as well as binary data onto the file. 

Syntax:

fs.writeSync( fd, string, position, encoding )

fs.writeSync( fd, buffer, offset, length, position )

Parameters:

• fd: It stands for file descriptor which is a number that identifies the file. We can use fs.openSync() method and pass a string within it describing the location of the file and it will return an integer which is the file descriptor.
• string: It is a string that will be written onto the file.
• position: It specifies the position in the file where the text will be written. If the position is not passed in the method or an integer value is not used for specifying position then it will start writing from the 0^th position. If a string is already written on that position the method will overwrite the new string passed on that position.
• encoding: It is a string that specifies character encoding. By default it is utf8.
• buffer: It contains the buffer type value like Buffer, Typed Array, Data View.
• offset: It is an integer value that specifies the part of the buffer to be written on the file.
• length: It is an integer value that specifies the number of bytes to write into the file.

Return value: Number of bytes written is returned.

Example:

Run index.js file using below command:

node index.js

Console Output:

File written successfully using writeSync()
Text written on file: Welcome to GeeksforGeeks,starting from position: 0
Number of Bytes written: 24

Example:

Run index.js file using below command:

node index.js

Console Output:

File written successfully using writeSync()
Buffer written on file: GeeksforGeeks: A computer science portal for geeks
starting from position: 0
Number of Bytes written: 50

Reference:

• https://nodejs.org/api/fs.html#fs_fs_writesync_fd_string_position_encoding
• https://nodejs.org/api/fs.html#fs_fs_writesync_fd_buffer_offset_length_position