1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
|
<?xml version="1.0" encoding="UTF-8"?>
<!--
SPDX-FileCopyrightText: 1996 , Rafal Maszkowski
SPDX-FileCopyrightText: 2007 - 2011, Nicolas François
SPDX-License-Identifier: BSD-3-Clause
-->
<!DOCTYPE refentry PUBLIC "-//OASIS//DTD DocBook V4.5//EN"
"http://www.oasis-open.org/docbook/xml/4.5/docbookx.dtd" [
<!ENTITY BCRYPT_MIN_ROUNDS SYSTEM "login.defs.d/BCRYPT_MIN_ROUNDS.xml">
<!ENTITY ENCRYPT_METHOD SYSTEM "login.defs.d/ENCRYPT_METHOD.xml">
<!ENTITY MAX_MEMBERS_PER_GROUP SYSTEM "login.defs.d/MAX_MEMBERS_PER_GROUP.xml">
<!ENTITY MD5_CRYPT_ENAB SYSTEM "login.defs.d/MD5_CRYPT_ENAB.xml">
<!ENTITY SHA_CRYPT_MIN_ROUNDS SYSTEM "login.defs.d/SHA_CRYPT_MIN_ROUNDS.xml">
<!ENTITY YESCRYPT_COST_FACTOR SYSTEM "login.defs.d/YESCRYPT_COST_FACTOR.xml">
<!-- SHADOW-CONFIG-HERE -->
]>
<refentry id='gpasswd.1'>
<!-- $Id$ -->
<refentryinfo>
<author>
<firstname>Rafal</firstname>
<surname>Maszkowski</surname>
<contrib>Creation, 1996</contrib>
</author>
<author>
<firstname>Thomas</firstname>
<surname>Kłoczko</surname>
<email>kloczek@pld.org.pl</email>
<contrib>shadow-utils maintainer, 2000 - 2007</contrib>
</author>
<author>
<firstname>Nicolas</firstname>
<surname>François</surname>
<email>nicolas.francois@centraliens.net</email>
<contrib>shadow-utils maintainer, 2007 - now</contrib>
</author>
</refentryinfo>
<refmeta>
<refentrytitle>gpasswd</refentrytitle>
<manvolnum>1</manvolnum>
<refmiscinfo class="sectdesc">User Commands</refmiscinfo>
<refmiscinfo class="source">shadow-utils</refmiscinfo>
<refmiscinfo class="version">&SHADOW_UTILS_VERSION;</refmiscinfo>
</refmeta>
<refnamediv id='name'>
<refname>gpasswd</refname>
<refpurpose>
<phrase condition="no_gshadow">
administer <filename>/etc/group</filename>
</phrase>
<phrase condition="gshadow">
administer <filename>/etc/group</filename> and
<filename>/etc/gshadow</filename>
</phrase>
</refpurpose>
</refnamediv>
<!-- body begins here -->
<refsynopsisdiv id='synopsis'>
<cmdsynopsis>
<command>gpasswd</command>
<arg choice='opt'>
<replaceable>option</replaceable>
</arg>
<arg choice='plain'>
<replaceable>group</replaceable>
</arg>
</cmdsynopsis>
</refsynopsisdiv>
<refsect1 id='description'>
<title>DESCRIPTION</title>
<para>
The <command>gpasswd</command> command is used to administer
<filename>/etc/group</filename><phrase condition="gshadow">,
and <filename>/etc/gshadow</filename></phrase>.
Every group can have
<phrase condition="gshadow">administrators,</phrase>
members and a password.
</para>
<para condition="gshadow">
System administrators can use the <option>-A</option> option to define
group administrator(s) and the <option>-M</option> option to define
members. They have all rights of group administrators and members.
</para>
<para>
<command>gpasswd</command> called by
<phrase condition="gshadow">a group administrator</phrase>
<phrase condition="no_gshadow">a system administrator</phrase>
with a group name only prompts for the new password of the
<replaceable>group</replaceable>.
</para>
<para>
If a password is set the members can still use <citerefentry>
<refentrytitle>newgrp</refentrytitle><manvolnum>1</manvolnum>
</citerefentry> without a password, and non-members must supply the
password.
</para>
<refsect2 id='notes_about_group_passwords'>
<title>Notes about group passwords</title>
<para>
Group passwords are an inherent security problem since more than one
person is permitted to know the password. However, groups are a
useful tool for permitting co-operation between different users.
</para>
</refsect2>
</refsect1>
<refsect1 id='options'>
<title>OPTIONS</title>
<para condition="gshadow">
Except for the <option>-A</option> and <option>-M</option> options,
the options cannot be combined.
</para>
<para condition="no_gshadow">
The options cannot be combined.
</para>
<para>
The options which apply to the <command>gpasswd</command> command are:
</para>
<variablelist remap='IP'>
<varlistentry>
<term>
<option>-a</option>, <option>--add</option> <replaceable>user</replaceable>
</term>
<listitem>
<para>
Add the <replaceable>user</replaceable> to the named
<replaceable>group</replaceable>.
</para>
</listitem>
</varlistentry>
</variablelist>
<variablelist remap='IP'>
<varlistentry>
<term>
<option>-d</option>, <option>--delete</option> <replaceable>user</replaceable>
</term>
<listitem>
<para>
Remove the <replaceable>user</replaceable> from the named
<replaceable>group</replaceable>.
</para>
</listitem>
</varlistentry>
</variablelist>
<variablelist remap='IP'>
<varlistentry>
<term><option>-h</option>, <option>--help</option></term>
<listitem>
<para>Display help message and exit.</para>
</listitem>
</varlistentry>
</variablelist>
<variablelist remap='IP'>
<varlistentry>
<term>
<option>-Q</option>, <option>--root</option> <replaceable>CHROOT_DIR</replaceable>
</term>
<listitem>
<para>
Apply changes in the <replaceable>CHROOT_DIR</replaceable>
directory and use the configuration files from the
<replaceable>CHROOT_DIR</replaceable> directory.
Only absolute paths are supported.
</para>
</listitem>
</varlistentry>
</variablelist>
<variablelist remap='IP'>
<varlistentry>
<term>
<option>-r</option>, <option>--remove-password</option>
</term>
<listitem>
<para>
Remove the password from the named <replaceable>group</replaceable>.
The group password will be empty.
Only group members will be allowed to use
<command>newgrp</command> to join the named
<replaceable>group</replaceable>.
</para>
</listitem>
</varlistentry>
</variablelist>
<variablelist remap='IP'>
<varlistentry>
<term>
<option>-R</option>, <option>--restrict</option>
</term>
<listitem>
<para>
Restrict the access to the named <replaceable>group</replaceable>.
The group password is set to "!".
Only group members with a password will be allowed to use
<command>newgrp</command> to join the named
<replaceable>group</replaceable>.
</para>
</listitem>
</varlistentry>
</variablelist>
<variablelist remap='IP' condition="gshadow">
<varlistentry>
<term>
<option>-A</option>, <option>--administrators</option> <replaceable>user</replaceable>,...
</term>
<listitem>
<para>
Set the list of administrative users.
</para>
</listitem>
</varlistentry>
</variablelist>
<variablelist remap='IP'>
<varlistentry>
<term>
<option>-M</option>, <option>--members</option> <replaceable>user</replaceable>,...
</term>
<listitem>
<para>
Set the list of group members.
</para>
</listitem>
</varlistentry>
</variablelist>
</refsect1>
<refsect1 id='caveats'>
<title>CAVEATS</title>
<para>
This tool only operates on the <filename>/etc/group</filename>
<phrase condition="gshadow"> and <filename>/etc/gshadow</filename>
files.</phrase>
<phrase condition="no_gshadow">file.</phrase>
Thus you cannot change any NIS or LDAP group. This must be performed
on the corresponding server.
</para>
</refsect1>
<refsect1 id='configuration'>
<title>CONFIGURATION</title>
<para>
The following configuration variables in
<filename>/etc/login.defs</filename> change the behavior of this
tool:
</para>
<variablelist>
&ENCRYPT_METHOD;
&MAX_MEMBERS_PER_GROUP;
&MD5_CRYPT_ENAB;
&SHA_CRYPT_MIN_ROUNDS; <!--This also document SHA_CRYPT_MAX_ROUNDS-->
</variablelist>
</refsect1>
<refsect1 id='files'>
<title>FILES</title>
<variablelist>
<varlistentry>
<term><filename>/etc/group</filename></term>
<listitem>
<para>Group account information.</para>
</listitem>
</varlistentry>
<varlistentry condition="gshadow">
<term><filename>/etc/gshadow</filename></term>
<listitem>
<para>Secure group account information.</para>
</listitem>
</varlistentry>
</variablelist>
</refsect1>
<refsect1 id='see_also'>
<title>SEE ALSO</title>
<para>
<citerefentry>
<refentrytitle>newgrp</refentrytitle><manvolnum>1</manvolnum>
</citerefentry>,
<citerefentry>
<refentrytitle>groupadd</refentrytitle><manvolnum>8</manvolnum>
</citerefentry>,
<citerefentry>
<refentrytitle>groupdel</refentrytitle><manvolnum>8</manvolnum>
</citerefentry>,
<citerefentry>
<refentrytitle>groupmod</refentrytitle><manvolnum>8</manvolnum>
</citerefentry>,
<citerefentry>
<refentrytitle>grpck</refentrytitle><manvolnum>8</manvolnum>
</citerefentry>,
<citerefentry>
<refentrytitle>group</refentrytitle><manvolnum>5</manvolnum>
</citerefentry><phrase condition="gshadow">,
<citerefentry>
<refentrytitle>gshadow</refentrytitle><manvolnum>5</manvolnum>
</citerefentry></phrase>.
</para>
</refsect1>
</refentry>
|
