chown

  • This function’s solution assumes a Unix-like operating system.

    The chown function in PHP will change the owner of a file to a different user ID, assuming the PHP process has sufficient privileges to do so.

    PHP

    chown('/path/to/foobar', 501);

    Ruby’s File.chown class method is used to accomplish the same task.

    Ruby

    File.chown(501, nil, '/path/to/foobar')

    The first argument of File.chown is the user, the second is the group, and the third is the file. Above, the group is set to nil. This will leave the group unchanged.

    Changing the Owner by User Name

    One nice feature of PHP’s chown is that the $user argument is mixed. It can accept either a user ID or a user name.

    PHP

    chown('/path/to/foobar', 'herbert');

    File.chown from Ruby is not as flexible. It only accepts numeric IDs. To change the user by name, we must first perform a lookup to get the user ID from the name.

    The Etc module from the Ruby Standard Library contains a method getpwnam that returns a Struct of information about a user by name, which includes the user ID. We can use this lookup the user ID and then pass it to File.chown.

    Ruby

    require 'etc'
 
uid = Etc.getpwnam('herbert').uid
File.chown(uid, nil, '/path/to/foobar')

    Changing the Owner with FileUtils

    An alternative to using File and Etc to change the owner of a file is to use FileUtils, also from the Ruby Standard Library. FileUtils.chown can change the owner by either user ID or name.

    Ruby

    require 'fileutils'
 
# equivalent
FileUtils.chown(501, nil, '/path/to/foobar')
FileUtils.chown('herbert', nil, '/path/to/foobar')

    The first argument of FileUtils.chown is the user, the second is the group, and the third is the file. Above, the group is set to nil. This will leave the group unchanged.

    Another useful method is FileUtils.chown_R, whose usage is the same but will recursively change all files in a given path.

    see also

← chop chr →

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