perlancar

NAME

Unix::Passwd::File - Manipulate /etc/{passwd,shadow,group,gshadow} entries

VERSION

This document describes version 0.18 of Unix::Passwd::File (from Perl distribution Unix-Passwd-File), released on 2015-03-13.

SYNOPSIS

 use Unix::Passwd::File;

 # list users. by default uses files in /etc (/etc/passwd, /etc/shadow, et al)
 my $res = list_users(); # [200, "OK", ["root", ...]]

 # change location of files, return details
 $res = list_users(etc_dir=>"/some/path", detail=>1);
     # [200, "OK", [{user=>"root", uid=>0, ...}, ...]]

 # also return detail, but return array entries instead of hash
 $res = list_users(detail=>1, with_field_names=>0);
     # [200, "OK", [["root", "x", 0, ...], ...]]

 # get user/group information
 $res = get_group(user=>"paijo"); # [200, "OK", {user=>"paijo", uid=>501, ...}]
 $res = get_user(user=>"titin");  # [404, "Not found"]

 # check whether user/group exists
 say user_exists(user=>"paijo");   # 1
 say group_exists(group=>"titin"); # 0

 # get all groups that user is member of
 $res = get_user_groups(user=>"paijo"); # [200, "OK", ["paijo", "satpam"]]

 # check whether user is member of a group
 $res = is_member(user=>"paijo", group=>"satpam"); # 1

 # adding user/group, by default adding user will also add a group with the same
 # name
 $res = add_user (user =>"ujang", ...); # [200, "OK", {uid=>540, gid=>541}]
 $res = add_group(group=>"ujang", ...); # [412, "Group already exists"]

 # modify user/group
 $res = modify_user(user=>"ujang", home=>"/newhome/ujang"); # [200, "OK"]
 $res = modify_group(group=>"titin"); # [404, "Not found"]

 # deleting user will also delete user's group
 $res = delete_user(user=>"titin");

 # change user password
 $res = set_user_password(user=>"ujang", pass=>"foobar");
 $res = modify_user(user=>"ujang", pass=>"foobar"); # same thing

 # add/delete user to/from group
 $res = add_user_to_group(user=>"ujang", group=>"wheel");
 $res = delete_user_from_group(user=>"ujang", group=>"wheel");

 # others
 $res = get_max_uid(); # [200, "OK", 65535]
 $res = get_max_gid(); # [200, "OK", 65534]

DESCRIPTION

This module can be used to read and manipulate entries in Unix system password files (/etc/passwd, /etc/group, /etc/group, /etc/gshadow; but can also be told to search in custom location, for testing purposes).

This module uses a procedural (non-OO) interface. Each function in this module open and read the passwd files once. Read-only functions like `list_users()` and `get_max_gid()` open in read-only mode. Functions that might write to the files like `add_user()` or `delete_group()` first lock `passwd.lock` file, open in read+write mode and also read the files in the first pass, then seek to the beginning and write back the files.

No caching is done so you should do your own if you need to.

FUNCTIONS

add_delete_user_groups(%args) -> [status, msg, result, meta]

Add or delete user from one or several groups.

This can be used to reduce several add_user_to_group() and/or delete_user_from_group() calls to a single call. So:

 add_delete_user_groups(user=>'u',add_to=>['a','b'],delete_from=>['c','d']);

is equivalent to:

 add_user_to_group     (user=>'u', group=>'a');
 add_user_to_group     (user=>'u', group=>'b');
 delete_user_from_group(user=>'u', group=>'c');
 delete_user_from_group(user=>'u', group=>'d');

except that add_delete_user_groups() does it in one pass.

Arguments ('*' denotes required arguments):

  • add_to => array[str] (default: [])

    List of group names to add the user as member of.

  • delete_from => array[str] (default: [])

    List of group names to remove the user as member of.

  • etc_dir => str (default: "/etc")

    Specify location of passwd files.

  • user* => str

Returns an enveloped result (an array).

First element (status) is an integer containing HTTP status code (200 means OK, 4xx caller error, 5xx function error). Second element (msg) is a string containing error message, or 'OK' if status is 200. Third element (result) is optional, the actual result. Fourth element (meta) is called result metadata and is optional, a hash that contains extra information.

Return value: (any)

add_group(%args) -> [status, msg, result, meta]

Add a new group.

Arguments ('*' denotes required arguments):

  • backup => bool (default: 0)

    Whether to backup when modifying files.

    Backup is written with .bak extension in the same directory. Unmodified file will not be backed up. Previous backup will be overwritten.

  • etc_dir => str (default: "/etc")

    Specify location of passwd files.

  • gid => any

    Pick a specific new GID.

    Adding a new group with duplicate GID is allowed.

  • group* => str

  • max_gid => int (default: 65535)

    Pick a range for new GID.

    If a free GID between min_gid and max_gid is not found, error 412 is returned.

  • members => any

    Fill initial members.

  • min_gid => int (default: 1000)

    Pick a range for new GID.

    If a free GID between min_gid and max_gid is not found, error 412 is returned.

Returns an enveloped result (an array).

First element (status) is an integer containing HTTP status code (200 means OK, 4xx caller error, 5xx function error). Second element (msg) is a string containing error message, or 'OK' if status is 200. Third element (result) is optional, the actual result. Fourth element (meta) is called result metadata and is optional, a hash that contains extra information.

Return value: (any)

add_user(%args) -> [status, msg, result, meta]

Add a new user.

Arguments ('*' denotes required arguments):

  • backup => bool (default: 0)

    Whether to backup when modifying files.

    Backup is written with .bak extension in the same directory. Unmodified file will not be backed up. Previous backup will be overwritten.

  • encpass => str

    Encrypted password.

  • etc_dir => str (default: "/etc")

    Specify location of passwd files.

  • expire_date => int

    The date of expiration of the account, expressed as the number of days since Jan 1, 1970.

  • gecos => str

    Usually, it contains the full username.

  • gid => any

    Pick a specific GID when creating group.

    Duplicate GID is allowed.

  • group => any

    Select primary group (default is group with same name as user).

    Normally, a user's primary group with group with the same name as user, which will be created if does not already exist. You can pick another group here, which must already exist (and in this case, the group with the same name as user will not be created).

  • home => str

    User's home directory.

  • last_pwchange => int

    The date of the last password change, expressed as the number of days since Jan 1, 1970.

  • max_gid => any

    Pick a range for GID when creating group.

  • max_pass_age => int

    The number of days after which the user will have to change her password.

  • max_uid => int (default: 65535)

    Pick a range for new UID.

    If a free UID between min_uid and max_uid is not found, error 412 is returned.

  • min_gid => any

    Pick a range for GID when creating group.

  • min_pass_age => int

    The number of days the user will have to wait before she will be allowed to change her password again.

  • min_uid => int (default: 1000)

    Pick a range for new UID.

    If a free UID between min_uid and max_uid is not found, error 412 is returned.

  • pass => str

    Password, generally should be "x" which means password is encrypted in shadow.

  • pass_inactive_period => int

    The number of days after a password has expired (see max_pass_age) during which the password should still be accepted (and user should update her password during the next login).

  • pass_warn_period => int

    The number of days before a password is going to expire (see max_pass_age) during which the user should be warned.

  • shell => str

    User's shell.

  • uid => any

    Pick a specific new UID.

    Adding a new user with duplicate UID is allowed.

  • user* => str

Returns an enveloped result (an array).

First element (status) is an integer containing HTTP status code (200 means OK, 4xx caller error, 5xx function error). Second element (msg) is a string containing error message, or 'OK' if status is 200. Third element (result) is optional, the actual result. Fourth element (meta) is called result metadata and is optional, a hash that contains extra information.

Return value: (any)

add_user_to_group(%args) -> [status, msg, result, meta]

Add user to a group.

Arguments ('*' denotes required arguments):

  • etc_dir => str (default: "/etc")

    Specify location of passwd files.

  • group* => str

  • user* => str

Returns an enveloped result (an array).

First element (status) is an integer containing HTTP status code (200 means OK, 4xx caller error, 5xx function error). Second element (msg) is a string containing error message, or 'OK' if status is 200. Third element (result) is optional, the actual result. Fourth element (meta) is called result metadata and is optional, a hash that contains extra information.

Return value: (any)

delete_group(%args) -> [status, msg, result, meta]

Delete a group.

Arguments ('*' denotes required arguments):

  • backup => bool (default: 0)

    Whether to backup when modifying files.

    Backup is written with .bak extension in the same directory. Unmodified file will not be backed up. Previous backup will be overwritten.

  • etc_dir => str (default: "/etc")

    Specify location of passwd files.

  • group* => str

Returns an enveloped result (an array).

First element (status) is an integer containing HTTP status code (200 means OK, 4xx caller error, 5xx function error). Second element (msg) is a string containing error message, or 'OK' if status is 200. Third element (result) is optional, the actual result. Fourth element (meta) is called result metadata and is optional, a hash that contains extra information.

Return value: (any)

delete_user(%args) -> [status, msg, result, meta]

Delete a user.

Arguments ('*' denotes required arguments):

  • backup => bool (default: 0)

    Whether to backup when modifying files.

    Backup is written with .bak extension in the same directory. Unmodified file will not be backed up. Previous backup will be overwritten.

  • etc_dir => str (default: "/etc")

    Specify location of passwd files.

  • user* => str

Returns an enveloped result (an array).

First element (status) is an integer containing HTTP status code (200 means OK, 4xx caller error, 5xx function error). Second element (msg) is a string containing error message, or 'OK' if status is 200. Third element (result) is optional, the actual result. Fourth element (meta) is called result metadata and is optional, a hash that contains extra information.

Return value: (any)

delete_user_from_group(%args) -> [status, msg, result, meta]

Delete user from a group.

Arguments ('*' denotes required arguments):

  • etc_dir => str (default: "/etc")

    Specify location of passwd files.

  • group* => str

  • user* => str

Returns an enveloped result (an array).

First element (status) is an integer containing HTTP status code (200 means OK, 4xx caller error, 5xx function error). Second element (msg) is a string containing error message, or 'OK' if status is 200. Third element (result) is optional, the actual result. Fourth element (meta) is called result metadata and is optional, a hash that contains extra information.

Return value: (any)

get_group(%args) -> [status, msg, result, meta]

Get group details by group name or gid.

Either group OR gid must be specified.

The function is not dissimilar to Unix's getgrnam() or getgrgid().

Arguments ('*' denotes required arguments):

  • etc_dir => str (default: "/etc")

    Specify location of passwd files.

  • gid => int

  • group => str

  • with_field_names => bool (default: 1)

    If false, don't return hash.

    By default, a hashref is returned containing field names and its values, e.g. {group=>"titin", pass=>"x", gid=>500, ...}. With with_field_names=>0, an arrayref is returned instead: ["titin", "x", 500, ...].

Returns an enveloped result (an array).

First element (status) is an integer containing HTTP status code (200 means OK, 4xx caller error, 5xx function error). Second element (msg) is a string containing error message, or 'OK' if status is 200. Third element (result) is optional, the actual result. Fourth element (meta) is called result metadata and is optional, a hash that contains extra information.

Return value: (any)

get_max_gid(%args) -> [status, msg, result, meta]

Get maximum GID used.

Arguments ('*' denotes required arguments):

  • etc_dir => str (default: "/etc")

    Specify location of passwd files.

Returns an enveloped result (an array).

First element (status) is an integer containing HTTP status code (200 means OK, 4xx caller error, 5xx function error). Second element (msg) is a string containing error message, or 'OK' if status is 200. Third element (result) is optional, the actual result. Fourth element (meta) is called result metadata and is optional, a hash that contains extra information.

Return value: (any)

get_max_uid(%args) -> [status, msg, result, meta]

Get maximum UID used.

Arguments ('*' denotes required arguments):

  • etc_dir => str (default: "/etc")

    Specify location of passwd files.

Returns an enveloped result (an array).

First element (status) is an integer containing HTTP status code (200 means OK, 4xx caller error, 5xx function error). Second element (msg) is a string containing error message, or 'OK' if status is 200. Third element (result) is optional, the actual result. Fourth element (meta) is called result metadata and is optional, a hash that contains extra information.

Return value: (any)

get_user(%args) -> [status, msg, result, meta]

Get user details by username or uid.

Either user OR uid must be specified.

The function is not dissimilar to Unix's getpwnam() or getpwuid().

Arguments ('*' denotes required arguments):

  • etc_dir => str (default: "/etc")

    Specify location of passwd files.

  • uid => int

  • user => str

  • with_field_names => bool (default: 1)

    If false, don't return hash.

    By default, a hashref is returned containing field names and its values, e.g. {user=>"titin", pass=>"x", uid=>500, ...}. With with_field_names=>0, an arrayref is returned instead: ["titin", "x", 500, ...].

Returns an enveloped result (an array).

First element (status) is an integer containing HTTP status code (200 means OK, 4xx caller error, 5xx function error). Second element (msg) is a string containing error message, or 'OK' if status is 200. Third element (result) is optional, the actual result. Fourth element (meta) is called result metadata and is optional, a hash that contains extra information.

Return value: (any)

get_user_groups(%args) -> [status, msg, result, meta]

Return groups which the user belongs to.

Arguments ('*' denotes required arguments):

  • detail => bool (default: 0)

    If true, return all fields instead of just group names.

  • etc_dir => str (default: "/etc")

    Specify location of passwd files.

  • user* => str

  • with_field_names => bool (default: 1)

    If false, don't return hash for each entry.

    By default, when detail=>1, a hashref is returned for each entry containing field names and its values, e.g. {group=>"titin", pass=>"x", gid=>500, ...}. With with_field_names=>0, an arrayref is returned instead: ["titin", "x", 500, ...].

Returns an enveloped result (an array).

First element (status) is an integer containing HTTP status code (200 means OK, 4xx caller error, 5xx function error). Second element (msg) is a string containing error message, or 'OK' if status is 200. Third element (result) is optional, the actual result. Fourth element (meta) is called result metadata and is optional, a hash that contains extra information.

Return value: (any)

group_exists(%args) -> bool

Check whether group exists.

Arguments ('*' denotes required arguments):

  • etc_dir => str (default: "/etc")

    Specify location of passwd files.

  • gid => int

  • group => str

Return value: (bool)

is_member(%args) -> bool

Check whether user is member of a group.

Arguments ('*' denotes required arguments):

  • etc_dir => str (default: "/etc")

    Specify location of passwd files.

  • group* => str

  • user* => str

Return value: (bool)

list_groups(%args) -> [status, msg, result, meta]

List Unix groups in group file.

Arguments ('*' denotes required arguments):

  • detail => bool (default: 0)

    If true, return all fields instead of just group names.

  • etc_dir => str (default: "/etc")

    Specify location of passwd files.

  • with_field_names => bool (default: 1)

    If false, don't return hash for each entry.

    By default, when detail=>1, a hashref is returned for each entry containing field names and its values, e.g. {group=>"titin", pass=>"x", gid=>500, ...}. With with_field_names=>0, an arrayref is returned instead: ["titin", "x", 500, ...].

Returns an enveloped result (an array).

First element (status) is an integer containing HTTP status code (200 means OK, 4xx caller error, 5xx function error). Second element (msg) is a string containing error message, or 'OK' if status is 200. Third element (result) is optional, the actual result. Fourth element (meta) is called result metadata and is optional, a hash that contains extra information.

Return value: (any)

list_users(%args) -> [status, msg, result, meta]

List Unix users in passwd file.

Arguments ('*' denotes required arguments):

  • detail => bool (default: 0)

    If true, return all fields instead of just usernames.

  • etc_dir => str (default: "/etc")

    Specify location of passwd files.

  • with_field_names => bool (default: 1)

    If false, don't return hash for each entry.

    By default, when detail=>1, a hashref is returned for each entry containing field names and its values, e.g. {user=>"titin", pass=>"x", uid=>500, ...}. With with_field_names=>0, an arrayref is returned instead: ["titin", "x", 500, ...].

Returns an enveloped result (an array).

First element (status) is an integer containing HTTP status code (200 means OK, 4xx caller error, 5xx function error). Second element (msg) is a string containing error message, or 'OK' if status is 200. Third element (result) is optional, the actual result. Fourth element (meta) is called result metadata and is optional, a hash that contains extra information.

Return value: (any)

list_users_and_groups(%args) -> [status, msg, result, meta]

List Unix users and groups in passwd/group files.

This is basically list_users() and list_groups() combined, so you can get both data in a single call. Data is returned in an array. Users list is in the first element, groups list in the second.

Arguments ('*' denotes required arguments):

  • detail => bool (default: 0)

    If true, return all fields instead of just names.

  • etc_dir => str (default: "/etc")

    Specify location of passwd files.

  • with_field_names => bool (default: 1)

    If false, don't return hash for each entry.

Returns an enveloped result (an array).

First element (status) is an integer containing HTTP status code (200 means OK, 4xx caller error, 5xx function error). Second element (msg) is a string containing error message, or 'OK' if status is 200. Third element (result) is optional, the actual result. Fourth element (meta) is called result metadata and is optional, a hash that contains extra information.

Return value: (any)

modify_group(%args) -> [status, msg, result, meta]

Modify an existing group.

Specify arguments to modify corresponding fields. Unspecified fields will not be modified.

Arguments ('*' denotes required arguments):

  • admins => str

    It must be a comma-separated list of user names, or empty.

  • backup => bool (default: 0)

    Whether to backup when modifying files.

    Backup is written with .bak extension in the same directory. Unmodified file will not be backed up. Previous backup will be overwritten.

  • encpass => str

    Encrypted password.

  • etc_dir => str (default: "/etc")

    Specify location of passwd files.

  • gid => int

    Numeric group ID.

  • group* => str

    Group name.

  • members => str

    List of usernames that are members of this group, separated by commas.

  • pass => str

    Password, generally should be "x" which means password is encrypted in gshadow.

Returns an enveloped result (an array).

First element (status) is an integer containing HTTP status code (200 means OK, 4xx caller error, 5xx function error). Second element (msg) is a string containing error message, or 'OK' if status is 200. Third element (result) is optional, the actual result. Fourth element (meta) is called result metadata and is optional, a hash that contains extra information.

Return value: (any)

modify_user(%args) -> [status, msg, result, meta]

Modify an existing user.

Specify arguments to modify corresponding fields. Unspecified fields will not be modified.

Arguments ('*' denotes required arguments):

  • backup => bool (default: 0)

    Whether to backup when modifying files.

    Backup is written with .bak extension in the same directory. Unmodified file will not be backed up. Previous backup will be overwritten.

  • encpass => str

    Encrypted password.

  • etc_dir => str (default: "/etc")

    Specify location of passwd files.

  • expire_date => int

    The date of expiration of the account, expressed as the number of days since Jan 1, 1970.

  • gecos => str

    Usually, it contains the full username.

  • gid => int

    Numeric primary group ID for this user.

  • home => str

    User's home directory.

  • last_pwchange => int

    The date of the last password change, expressed as the number of days since Jan 1, 1970.

  • max_pass_age => int

    The number of days after which the user will have to change her password.

  • min_pass_age => int

    The number of days the user will have to wait before she will be allowed to change her password again.

  • pass_inactive_period => int

    The number of days after a password has expired (see max_pass_age) during which the password should still be accepted (and user should update her password during the next login).

  • pass_warn_period => int

    The number of days before a password is going to expire (see max_pass_age) during which the user should be warned.

  • shell => str

    User's shell.

  • uid => int

    Numeric user ID.

  • user* => str

    User (login) name.

Returns an enveloped result (an array).

First element (status) is an integer containing HTTP status code (200 means OK, 4xx caller error, 5xx function error). Second element (msg) is a string containing error message, or 'OK' if status is 200. Third element (result) is optional, the actual result. Fourth element (meta) is called result metadata and is optional, a hash that contains extra information.

Return value: (any)

set_user_groups(%args) -> [status, msg, result, meta]

Set the groups that a user is member of.

Arguments ('*' denotes required arguments):

  • etc_dir => str (default: "/etc")

    Specify location of passwd files.

  • groups* => array[str] (default: [])

    List of group names that user is member of.

    Aside from this list, user will not belong to any other group.

  • user* => str

Returns an enveloped result (an array).

First element (status) is an integer containing HTTP status code (200 means OK, 4xx caller error, 5xx function error). Second element (msg) is a string containing error message, or 'OK' if status is 200. Third element (result) is optional, the actual result. Fourth element (meta) is called result metadata and is optional, a hash that contains extra information.

Return value: (any)

set_user_password(%args) -> [status, msg, result, meta]

Set user's password.

Arguments ('*' denotes required arguments):

  • backup => bool (default: 0)

    Whether to backup when modifying files.

    Backup is written with .bak extension in the same directory. Unmodified file will not be backed up. Previous backup will be overwritten.

  • etc_dir => str (default: "/etc")

    Specify location of passwd files.

  • pass* => str

  • user* => str

Returns an enveloped result (an array).

First element (status) is an integer containing HTTP status code (200 means OK, 4xx caller error, 5xx function error). Second element (msg) is a string containing error message, or 'OK' if status is 200. Third element (result) is optional, the actual result. Fourth element (meta) is called result metadata and is optional, a hash that contains extra information.

Return value: (any)

user_exists(%args) -> bool

Check whether user exists.

Arguments ('*' denotes required arguments):

  • etc_dir => str (default: "/etc")

    Specify location of passwd files.

  • uid => int

  • user => str

Return value: (bool)

SEE ALSO

Old modules on CPAN which do not support shadow files are pretty useless to me (e.g. Unix::ConfigFile). Shadow passwords have been around since 1988 (and in Linux since 1992), FFS!

Passwd::Unix. I created a fork of Passwd::Unix v0.52 called Passwd::Unix::Alt in 2011 to fix some of the deficiencies/quirks in Passwd::Unix, including: lack of tests, insistence of running as root (despite allowing custom passwd files), use of not-so-ubiquitous bzip2, etc. Then in 2012 I decided to create Unix::Passwd::File. Here are how Unix::Passwd::File differs compared to Passwd::Unix (and Passwd::Unix::Alt):

  • tests in distribution

  • no need to run as root

  • no need to be able to read the shadow file for some operations

    For example, list_users() will simply not return the encpass field if the shadow file is unreadable. Of course, access to shadow file is required when getting or setting password.

  • strictly procedural (non-OO) interface

    I consider this a feature :-)

  • detailed error message for each operation

  • removal of global error variable

  • working locking

    Locking is done by locking passwd.lock file.

Setup::Unix::User and Setup::Unix::Group, which use this module.

Rinci

HOMEPAGE

Please visit the project's homepage at https://metacpan.org/release/Unix-Passwd-File.

SOURCE

Source repository is at https://github.com/perlancar/perl-Unix-Passwd-File.

BUGS

Please report any bugs or feature requests on the bugtracker website https://rt.cpan.org/Public/Dist/Display.html?Name=Unix-Passwd-File

When submitting a bug or request, please include a test-file or a patch to an existing test-file that illustrates the bug or desired feature.

AUTHOR

perlancar <perlancar@cpan.org>

COPYRIGHT AND LICENSE

This software is copyright (c) 2015 by perlancar@cpan.org.

This is free software; you can redistribute it and/or modify it under the same terms as the Perl 5 programming language system itself.