The
fs.fchmod() method is used to change the permissions of a given file descriptor. These permissions can be specified as a parameter using string constants or octal numbers that corresponding to their respective file modes.
Note: The Windows platform only supports the changing of the write permission. It does not support the distinction between the permissions of users, groups, or others.
Syntax:
fs.fchmod( fd, mode, callback )
Parameters: This method accept three parameters as mentioned above and described below:
- fd: It is an integer value which denotes the file descriptor of the file of which the permission has to be changed.
- mode: It is string constant or octal constant that denotes the permission to be granted. The logical OR operator can be used to separate multiple permissions.
- callback: It is a function that would be called when the method is executed.
- err: It is an error that would be thrown if the method fails.
Below examples illustrate the
fs.fchmod() method in Node.js:
Example 1: This example shows the usage of string constants and OR operator to give the file permissions.
Output:
Giving only read permission to the user
Current File Mode: 33024
File Contents: This file has been written over.
Trying to write to file
Error Found, Code: EACCES
Giving both read and write permission to the user
Current File Mode: 33152
Trying to write to file
File Contents: This file has been written over.
Example 2: This example shows the usage of octal constants to give the file permissions.
Output:
Giving only read permission to everyone
Current File Mode: 33060
File Contents: This file has been written over.
Trying to write to file
Error Found, Code: EACCES
Giving both read and write permission to everyone
Current File Mode: 33206
Trying to write to file
File Contents: This file has been written over.
Reference: https://nodejs.org/api/fs.html#fs_fs_fchmod_fd_mode_callback
