Changes file mode

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- PHP Manual
- Filesystem Functions
- Changes file mode

# chmod

(PHP 4, PHP 5, PHP 7, PHP 8)

chmod — Changes file mode

### Description

chmod(string `$filename`, int `$permissions`): bool

Attempts to change the mode of the specified file to that given in `permissions`.

### Parameters

`filename`

  Path to the file.

`permissions`

  Note that `permissions` is not automatically assumed to be an octal value, so to ensure the expected operation, you need to prefix `permissions` with a zero (0). Strings such as "g+w" will not work properly.

      <?phpchmod("/somedir/somefile", 755);   // decimal; probably incorrectchmod("/somedir/somefile", "u+rwx,go+rx"); // string; incorrectchmod("/somedir/somefile", 0755);  // octal; correct value of mode?>

  The `permissions` parameter consists of three octal number components specifying access restrictions for the owner, the user group in which the owner is in, and to everybody else in this order. One component can be computed by adding up the needed permissions for that target user base. Number 1 means that you grant execute rights, number 2 means that you make the file writeable, number 4 means that you make the file readable. Add up these numbers to specify needed rights. You can also read more about modes on Unix systems with 'man 1 chmod' and 'man 2 chmod'.

      <?php// Read and write for owner, nothing for everybody elsechmod("/somedir/somefile", 0600);// Read and write for owner, read for everybody elsechmod("/somedir/somefile", 0644);// Everything for owner, read and execute for otherschmod("/somedir/somefile", 0755);// Everything for owner, read and execute for owner's groupchmod("/somedir/somefile", 0750);?>

### Return Values

Returns `true` on success or `false` on failure.

### Errors/Exceptions

Upon failure, an `E_WARNING` is emitted.

### Notes

> Note:

> The current user is the user under which PHP runs. It is probably not the same user you use for normal shell or FTP access. The mode can be changed only by user who owns the file on most systems.

> Note: This function will not work on remote files as the file to be examined must be accessible via the server's filesystem.

### See Also

- chown() - Changes file owner
- chgrp() - Changes file group
- fileperms() - Gets file permissions
- stat() - Gives information about a file