# class System::User

- System::User
- Reference
- Object

##
Overview

Represents a user on the host system.

NOTE To use User, you must explicitly import it with `require "system/user"`

Users can be retrieved by either username or their user ID:

    require "system/user"

    System::User.find_by name: "root"
    System::User.find_by id: "0"

##
Included Modules

- Crystal::System::User

##
Defined in:

system/user.cr

##
Class Method Summary

- .find_by(*, name : String) : System::User

  Returns the user associated with the given username.

- .find_by(*, id : String) : System::User

  Returns the user associated with the given ID.

- .find_by?(*, name : String) : System::User | Nil

  Returns the user associated with the given username.

- .find_by?(*, id : String) : System::User | Nil

  Returns the user associated with the given ID.

##
Instance Method Summary

- #==(other : self)

  Returns `true` if this reference is the same as other.

- #group_id : String

  The user's primary group identifier.

- #hash(hasher)

  See `Object#hash(hasher)`

- #home_directory : String

  The user's home directory.

- #id : String

  The user's identifier.

- #name : String

  The user's real or full name.

- #shell : String

  The user's login shell.

- #to_s(io)
- #username : String

  The user's username.

### Instance methods inherited from module `Crystal::System::User`

system_group_id system_group_id, system_home_directory system_home_directory, system_id system_id, system_name system_name, system_shell system_shell, system_username system_username

### Constructor methods inherited from module `Crystal::System::User`

new(username : String, id : String, group_id : String, name : String, home_directory : String, shell : String) new

### Class methods inherited from module `Crystal::System::User`

from_id?(id : String) from_id?, from_username?(username : String) from_username?

### Instance methods inherited from class `Reference`

==(other : self)
==(other : JSON::Any)
==(other : YAML::Any)
==(other) ==, dup dup, hash(hasher) hash, initialize initialize, inspect(io : IO) : Nil inspect, object_id : UInt64 object_id, pretty_print(pp) : Nil pretty_print, same?(other : Reference) : Bool
same?(other : Nil) same?, to_s(io : IO) : Nil to_s

### Constructor methods inherited from class `Reference`

new new, unsafe_construct(address : Pointer, *args, **opts) : self unsafe_construct

### Class methods inherited from class `Reference`

pre_initialize(address : Pointer) pre_initialize

### Instance methods inherited from class `Object`

! : Bool !, !=(other) !=, !~(other) !~, ==(other) ==, ===(other : JSON::Any)
===(other : YAML::Any)
===(other) ===, =~(other) =~, as(type : Class) as, as?(type : Class) as?, class class, dup dup, hash(hasher)
hash hash, in?(collection : Object) : Bool
in?(*values : Object) : Bool in?, inspect(io : IO) : Nil
inspect : String inspect, is_a?(type : Class) : Bool is_a?, itself itself, nil? : Bool nil?, not_nil!(message)
not_nil! not_nil!, pretty_inspect(width = 79, newline = "\n", indent = 0) : String pretty_inspect, pretty_print(pp : PrettyPrint) : Nil pretty_print, responds_to?(name : Symbol) : Bool responds_to?, tap(&) tap, to_json(io : IO) : Nil
to_json : String to_json, to_pretty_json(indent : String = " ") : String
to_pretty_json(io : IO, indent : String = " ") : Nil to_pretty_json, to_s(io : IO) : Nil
to_s : String to_s, to_yaml(io : IO) : Nil
to_yaml : String to_yaml, try(&) try, unsafe_as(type : T.class) forall T unsafe_as

### Class methods inherited from class `Object`

from_json(string_or_io, root : String)
from_json(string_or_io) from_json, from_yaml(string_or_io : String | IO) from_yaml

### Macros inherited from class `Object`

class_getter(*names, &block) class_getter, class_getter!(*names) class_getter!, class_getter?(*names, &block) class_getter?, class_property(*names, &block) class_property, class_property!(*names) class_property!, class_property?(*names, &block) class_property?, class_setter(*names) class_setter, def_clone def_clone, def_equals(*fields) def_equals, def_equals_and_hash(*fields) def_equals_and_hash, def_hash(*fields) def_hash, delegate(*methods, to object) delegate, forward_missing_to(delegate) forward_missing_to, getter(*names, &block) getter, getter!(*names) getter!, getter?(*names, &block) getter?, property(*names, &block) property, property!(*names) property!, property?(*names, &block) property?, setter(*names) setter

##
Class Method Detail

def self.find_by(*, name : String) : System::User #

Returns the user associated with the given username.

Raises `NotFoundError` if no such user exists.

def self.find_by(*, id : String) : System::User #

Returns the user associated with the given ID.

Raises `NotFoundError` if no such user exists.

def self.find_by?(*, name : String) : System::User | Nil #

Returns the user associated with the given username.

Returns `nil` if no such user exists.

def self.find_by?(*, id : String) : System::User | Nil #

Returns the user associated with the given ID.

Returns `nil` if no such user exists.

##
Instance Method Detail

def ==(other : self) #
Description copied from class Reference

Returns `true` if this reference is the same as other. Invokes `same?`.

def group_id : String #

The user's primary group identifier.

def hash(hasher) #
Description copied from class Reference

See `Object#hash(hasher)`

def home_directory : String #

The user's home directory.

def id : String #

The user's identifier.

def name : String #

The user's real or full name.

May not be present on all platforms. Returns the same value as `#username` if neither a real nor full name is available.

def shell : String #

The user's login shell.

def to_s(io) #
def username : String #

The user's username.