'\" t
.\"     Title: newusers
.\"    Author: Julianne Frances Haugh
.\" Generator: DocBook XSL Stylesheets vsnapshot <http://docbook.sf.net/>
.\"      Date: 30/07/2026
.\"    Manual: System Management Commands
.\"    Source: shadow-utils 4.20.0
.\"  Language: French
.\"
.TH "NEWUSERS" "8" "30/07/2026" "shadow\-utils 4\&.20\&.0" "System Management Commands"
.\" -----------------------------------------------------------------
.\" * Define some portability stuff
.\" -----------------------------------------------------------------
.\" ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
.\" http://bugs.debian.org/507673
.\" http://lists.gnu.org/archive/html/groff/2009-02/msg00013.html
.\" ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
.ie \n(.g .ds Aq \(aq
.el       .ds Aq '
.\" -----------------------------------------------------------------
.\" * set default formatting
.\" -----------------------------------------------------------------
.\" disable hyphenation
.nh
.\" disable justification (adjust text to left margin only)
.ad l
.\" -----------------------------------------------------------------
.\" * MAIN CONTENT STARTS HERE *
.\" -----------------------------------------------------------------
.SH "NOM"
newusers \- Mettre \(`a jour, ou cr\('eer de nouveaux utilisateurs par lots
.SH "SYNOPSIS"
.HP \w'\fBnewusers\fR\ 'u
\fBnewusers\fR [\fIoptions\fR] [\fIfile\fR]
.SH "DESCRIPTION"
.PP
The
\fBnewusers\fR
command reads a
\fIfile\fR
(or the standard input by default) and uses this information to update a set of existing users or to create new users\&. Each line is in the same format as the standard password file (see
\fBpasswd\fR(5)) with the exceptions explained below:
.PP
pw_name:pw_passwd:pw_uid:pw_gid:pw_gecos:pw_dir:pw_shell
.PP
\fIpw_name\fR
.RS 4
C\*(Aqest le nom de l\*(Aqutilisateur\&.
.sp
It can be the name of a new user or the name of an existing user (or a user created before by
\fBnewusers\fR)\&. In case of an existing user, the user\*(Aqs information will be changed, otherwise a new user will be created\&.
.RE
.PP
\fIpw_passwd\fR
.RS 4
If this field is not empty, it will be encrypted and used as the new value of the encrypted password\&.
.RE
.PP
\fIpw_uid\fR
.RS 4
Ce champ est utilis\('e pour d\('efinir l\*(AqUID de l\*(Aqutilisateur\&.
.sp
If the field is empty, a new (unused) UID will be defined automatically by
\fBnewusers\fR\&.
.sp
Si ce champ contient un nombre, ce nombre sera utilis\('e comme UID\&.
.sp
If this field contains the name of an existing user (or the name of a user created before by
\fBnewusers\fR), the UID of the specified user will be used\&.
.sp
Si l\*(AqUID d\*(Aqun utilisateur existant est modifi\('e, vous devrez configurer vous\-m\(^eme le propri\('etaire des fichiers de l\*(Aqutilisateur\&.
.RE
.PP
\fIpw_gid\fR
.RS 4
Ce champ est utilis\('e pour d\('efinir l\*(Aqidentifiant du groupe primaire de l\*(Aqutilisateur\&.
.sp
If this field contains the name of an existing group (or a group created before by
\fBnewusers\fR), the GID of this group will be used as the primary group ID for the user\&.
.sp
Si ce champ est un nombre, ce nombre sera utilis\('e comme identifiant de groupe primaire de cet utilisateur\&. Si aucun groupe n\*(Aqexiste avec ce GID, un nouveau groupe sera cr\('e\('e avec ce GID et le nom de l\*(Aqutilisateur\&.
.sp
If this field is empty, a new group will be created with the name of the user and a GID will be automatically defined by
\fBnewusers\fR
to be used as the primary group ID for the user and as the GID for the new group\&.
.sp
If this field contains the name of a group which does not exist (and was not created before by
\fBnewusers\fR), a new group will be created with the specified name and a GID will be automatically defined by
\fBnewusers\fR
to be used as the primary group ID for the user and GID for the new group\&.
.RE
.PP
\fIpw_gecos\fR
.RS 4
Ce champ est copi\('e dans le champ GECOS de l\*(Aqutilisateur\&.
.RE
.PP
\fIpw_dir\fR
.RS 4
Ce champ est utilis\('e pour d\('efinir le r\('epertoire personnel de l\*(Aqutilisateur\&.
.sp
If this field does not specify an existing directory, the specified directory is created, with ownership set to the user being created or updated and its primary group\&. Note that
\fInewusers does not create parent directories \fR
of the new user\*(Aqs home directory\&. The newusers command will fail to create the home directory if the parent directories do not exist, and will send a message to stderr informing the user of the failure\&. The newusers command will not halt or return a failure to the calling shell if it fails to create the home directory, it will continue to process the batch of new users specified\&.
.sp
If the home directory of an existing user is changed,
\fBnewusers\fR
does not move or copy the content of the old directory to the new location\&. This should be done manually\&.
.RE
.PP
\fIpw_shell\fR
.RS 4
Ce champ d\('efinit l\*(Aqinterpr\('eteur de commande de l\*(Aqutilisateur\&. Aucune v\('erification n\*(Aqest effectu\('ee sur ce champ\&.
.RE
.PP
\fBnewusers\fR
first tries to create or change all the specified users, and then write these changes to the user or group databases\&. If an error occurs (except in the final writes to the databases), no changes are committed to the databases\&.
.PP
Lors du premier passage, les utilisateurs sont cr\('e\('es avec un mot de passe verrouill\('e (les mots de passe ne sont pas modifi\('es pour les utilisateurs non cr\('e\('es)\&. Un second passage est utilis\('e pour mettre \(`a jour les mots de passe en utilisant PAM\&. Les \('echecs de mise \(`a jour des mots de passe sont signal\('es, mais n\*(Aqemp\(^echent pas les mises \(`a jour des autres mots de passe\&.
.PP
Cette commande a \('et\('e con\(,cue pour les gros syst\(`emes pour lesquels un grand nombre de comptes sont mis \(`a jour en m\(^eme temps\&.
.SH "OPTIONS"
.PP
The options which apply to the
\fBnewusers\fR
command are:
.PP
\fB\-\-badname\fR\ \&
.RS 4
Allow names that do not conform to standards\&.
.RE
.PP
\fB\-h\fR, \fB\-\-help\fR
.RS 4
Afficher un message d\*(Aqaide et quitter\&.
.RE
.PP
\fB\-r\fR, \fB\-\-system\fR
.RS 4
Cr\('eer un compte syst\(`eme\&.
.sp
System users will be created with no aging information in
/etc/shadow, and their numeric identifiers are chosen in the
\fBSYS_UID_MIN\fR\-\fBSYS_UID_MAX\fR
range, defined in
login\&.defs, instead of
\fBUID_MIN\fR\-\fBUID_MAX\fR
(and their
\fBGID\fR
counterparts for the creation of groups)\&.
.RE
.PP
\fB\-R\fR, \fB\-\-root\fR\ \&\fICHROOT_DIR\fR
.RS 4
Apply changes in the
\fICHROOT_DIR\fR
directory and use the configuration files from the
\fICHROOT_DIR\fR
directory\&. Only absolute paths are supported\&. No SELINUX support\&.
.RE
.SH "AVERTISSEMENTS"
.PP
Le fichier d\*(Aqentr\('ee doit \(^etre correctement prot\('eg\('e puisqu\*(Aqil contient des mots de passe en clair\&.
.SH "CONFIGURATION"
.PP
The following configuration variables in
/etc/login\&.defs
change the behavior of this tool:
.PP
\fBGID_MAX\fR (number), \fBGID_MIN\fR (number)
.RS 4
Range of group IDs used for the creation of regular groups by
\fBuseradd\fR,
\fBgroupadd\fR, or
\fBnewusers\fR\&.
.sp
The default value for
\fBGID_MIN\fR
(resp\&.
\fBGID_MAX\fR) is 1000 (resp\&. 60000)\&.
.RE
.PP
\fBHOME_MODE\fR (number)
.RS 4
The mode for new home directories\&. If not specified, the
\fBUMASK\fR
is used to create the mode\&.
.sp
\fBuseradd\fR
and
\fBnewusers\fR
use this to set the mode of the home directory they create\&.
.RE
.PP
\fBMAX_MEMBERS_PER_GROUP\fR (number)
.RS 4
Maximum members per group entry\&. When the maximum is reached, a new group entry (line) is started in
/etc/group
(with the same name, same password, and same GID)\&.
.sp
La valeur par d\('efaut est 0, ce qui signifie qu\*(Aqil n\*(Aqy a pas de limites pour le nombre de membres dans un groupe\&.
.sp
Cette fonctionnalit\('e (groupe d\('ecoup\('e) permet de limiter la longueur des lignes dans le fichier de groupes\&. Ceci est utile pour s\*(Aqassurer que les lignes pour les groupes NIS ne sont pas plus grandes que 1024 caract\(`eres\&.
.sp
Si vous avez besoin de configurer cette limite, vous pouvez utiliser 25\&.
.sp
Remarque\ \&: les groupes d\('ecoup\('es ne sont peut\-\(^etre pas pris en charge par tous les outils (m\(^eme dans la suite d\*(Aqoutils Shadow)\&. Vous ne devriez pas utiliser cette variable, sauf si vous en avez vraiment besoin\&.
.RE
.PP
\fBPASS_MAX_DAYS\fR (number)
.RS 4
Nombre maximum de jours de validit\('e d\*(Aqun mot de passe\&. Apr\(`es cette dur\('ee, une modification du mot de passe est obligatoire\&. S\*(Aqil n\*(Aqest pas pr\('ecis\('e, la valeur de \-1 est utilis\('ee (ce qui enl\(`eve toute restriction)\&.
.RE
.PP
\fBPASS_WARN_AGE\fR (number)
.RS 4
The number of days warning given before a password expires\&. A zero means warning is given only upon the day of expiration, a value of \-1 means no warning is given\&. If not specified, no warning will be provided\&.
.RE
.PP
\fBSUB_GID_MIN\fR (number), \fBSUB_GID_MAX\fR (number), \fBSUB_GID_COUNT\fR (number)
.RS 4
If
/etc/subuid
exists, the commands
\fBuseradd\fR
and
\fBnewusers\fR
(unless the user already have subordinate group IDs) allocate
\fBSUB_GID_COUNT\fR
unused group IDs from the range
\fBSUB_GID_MIN\fR
to
\fBSUB_GID_MAX\fR
for each new user\&.
.sp
The default values for
\fBSUB_GID_MIN\fR,
\fBSUB_GID_MAX\fR,
\fBSUB_GID_COUNT\fR
are respectively 100000, 600100000 and 65536\&.
.RE
.PP
\fBSUB_GID_DETERMINISTIC\fR (boolean)
.RS 4
If set to
\fIyes\fR, the commands
\fBuseradd\fR,
\fBusermod\fR, and
\fBnewusers\fR
will calculate subordinate GID ranges deterministically based on the user\*(Aqs UID instead of searching for the next free range\&. The formula used is:
.sp
.if n \{\
.RS 4
.\}
.nf
      start = SUB_GID_MIN + ((UID \- UID_MIN) * SUB_GID_COUNT)
      end   = start + SUB_GID_COUNT \- 1
    
.fi
.if n \{\
.RE
.\}
.sp
This ensures the same UID always receives the same subordinate GID range on every system, making it suitable for environments with centralized user management (LDAP, NIS, etc\&.) or synchronized UIDs across systems\&.
.sp
If
\fBSUB_GID_DETERMINISTIC\fR
is enabled, you can use
\fBusermod \-\-add\-subgids \-S\fR
to produce deterministic subgids\&.
.sp
\fBWARNING\fR: Because
\fBUID_MIN\fR
is used to calculate the ranges, any change of
\fBUID_MIN\fR
will change the ranges calculated\&.
\fBSUB_GID_COUNT\fR
is used to calculate the ranges, any change of
\fBSUB_GID_COUNT\fR
will change the ranges calculated\&. Users with identities less than
\fBUID_MIN\fR
are incompatible with
\fBSUB_GID_DETERMINISTIC\fR, but can still be set manually\&.
.sp
\fBWARNING\fR: Do not mix deterministic and linear (default) allocation on the same system or across systems sharing
/etc/subgid
via network storage (NFS, etc\&.)\&. Mixing allocation methods
\fB will cause subordinate ID range conflicts and overlaps \fR\&.
.sp
The default value for
\fBSUB_GID_DETERMINISTIC\fR
is
\fIno\fR\&.
.SS "Range Calculation Examples"
With default configuration (\fBUID_MIN\fR=1000,
\fBSUB_GID_MIN\fR=100000,
\fBSUB_GID_COUNT\fR=65536):
.TS
allbox tab(:);
lB lB lB.
T{
UID
T}:T{
Calculation
T}:T{
Subordinate GID Range
T}
.T&
l l l
l l l
l l l
l l l.
T{
1000
T}:T{
100000 + ((1000\-1000) * 65536)
T}:T{
100000\-165535
T}
T{
1001
T}:T{
100000 + ((1001\-1000) * 65536)
T}:T{
165536\-231071
T}
T{
1002
T}:T{
100000 + ((1002\-1000) * 65536)
T}:T{
231072\-296607
T}
T{
1100
T}:T{
100000 + ((1100\-1000) * 65536)
T}:T{
6653600\-6719135
T}
.TE
.sp 1
.SS "Subordinate ID Space Planning"
When planning subordinate ID allocation, calculate the maximum number of users the space can accommodate:
.sp
.if n \{\
.RS 4
.\}
.nf
      capacity = (SUB_GID_MAX \- SUB_GID_MIN) / SUB_GID_COUNT
      
.fi
.if n \{\
.RE
.\}
.sp
With default values: (600100000 \- 100000) / 65536 ≈ 9155 users\&.
.sp
For high\-density environments with many users and smaller allocations:
.sp
.if n \{\
.RS 4
.\}
.nf
        SUB_GID_COUNT  4096
        SUB_GID_MIN    100000
        SUB_GID_MAX    10000000
      
.fi
.if n \{\
.RE
.\}
.sp
This gives: (10000000 \- 100000) / 4096 ≈ 2417 users\&.
.RE
.PP
\fBUNSAFE_SUB_GID_DETERMINISTIC_WRAP\fR (boolean)
.RS 4
\fB WARNING: SECURITY RISK \- MAY CAUSE RANGE OVERLAPS AND PRIVILEGE ESCALATION! \fR
.sp
Only effective when
\fBSUB_GID_DETERMINISTIC\fR
is set to
\fIyes\fR\&.
.sp
When set to
\fIyes\fR
(WRAP MODE), allows the deterministic range calculation to wrap around using modulo arithmetic when a UID would overflow the configured subordinate ID space\&. The subordinate ID space is treated as a ring buffer\&.
.sp
\fBWARNING\fR: Range overlaps can lead to container escapes and privilege escalation\&. For example, with
\fBSUB_GID_MIN\fR=100000,
\fBSUB_GID_MAX\fR=200000,
\fBSUB_GID_COUNT\fR=65536, User A (UID 1000) gets range [100000, 165535] and User B (UID 1001) wraps and overlaps with User A\&. User B\*(Aqs container can now access files from User A\*(Aqs containers\&.
.sp
Use
\fBonly\fR
in development, testing, or tightly constrained lab environments\&.
.sp
When set to
\fIno\fR
(default), any arithmetic overflow or range exceeding
\fBSUB_GID_MAX\fR
is a hard error\&. This guarantees non\-overlapping, monotonic allocation\&.
.sp
The default value for
\fBUNSAFE_SUB_GID_DETERMINISTIC_WRAP\fR
is
\fIno\fR\&.
.RE
.PP
\fBSUB_UID_MIN\fR (number), \fBSUB_UID_MAX\fR (number), \fBSUB_UID_COUNT\fR (number)
.RS 4
If
/etc/subuid
exists, the commands
\fBuseradd\fR
and
\fBnewusers\fR
(unless the user already have subordinate user IDs) allocate
\fBSUB_UID_COUNT\fR
unused user IDs from the range
\fBSUB_UID_MIN\fR
to
\fBSUB_UID_MAX\fR
for each new user\&.
.sp
The default values for
\fBSUB_UID_MIN\fR,
\fBSUB_UID_MAX\fR,
\fBSUB_UID_COUNT\fR
are respectively 100000, 600100000 and 65536\&.
.RE
.PP
\fBSUB_UID_DETERMINISTIC\fR (boolean)
.RS 4
If set to
\fIyes\fR, the commands
\fBuseradd\fR,
\fBusermod\fR, and
\fBnewusers\fR
will calculate subordinate UID ranges deterministically based on the user\*(Aqs UID instead of searching for the next free range\&. The formula used is:
.sp
.if n \{\
.RS 4
.\}
.nf
      start = SUB_UID_MIN + ((UID \- UID_MIN) * SUB_UID_COUNT)
      end   = start + SUB_UID_COUNT \- 1
    
.fi
.if n \{\
.RE
.\}
.sp
This ensures the same UID always receives the same subordinate UID range on every system, making it suitable for environments with centralized user management (LDAP, NIS, etc\&.) or synchronized UIDs across systems\&.
.sp
If
\fBSUB_UID_DETERMINISTIC\fR
is enabled, you can use
\fBusermod \-\-add\-subuids \-S\fR
to produce deterministic subuids\&.
.sp
\fBWARNING\fR: Because
\fBUID_MIN\fR
is used to calculate the ranges, any change of
\fBUID_MIN\fR
will change the ranges calculated\&.
\fBSUB_UID_COUNT\fR
is used to calculate the ranges, any change of
\fBSUB_UID_COUNT\fR
will change the ranges calculated\&. Users with identities less than
\fBUID_MIN\fR
are incompatible with
\fBSUB_UID_DETERMINISTIC\fR, but can still be set manually\&.
.sp
\fBWARNING\fR: Do not mix deterministic and linear (default) allocation on the same system or across systems sharing
/etc/subuid
via network storage (NFS, etc\&.)\&. Mixing allocation methods
\fB will cause subordinate ID range conflicts and overlaps \fR\&.
.sp
The default value for
\fBSUB_UID_DETERMINISTIC\fR
is
\fIno\fR\&.
.SS "Range Calculation Examples"
With default configuration (\fBUID_MIN\fR=1000,
\fBSUB_UID_MIN\fR=100000,
\fBSUB_UID_COUNT\fR=65536):
.TS
allbox tab(:);
lB lB lB.
T{
UID
T}:T{
Calculation
T}:T{
Subordinate UID Range
T}
.T&
l l l
l l l
l l l
l l l.
T{
1000
T}:T{
100000 + ((1000\-1000) * 65536)
T}:T{
100000\-165535
T}
T{
1001
T}:T{
100000 + ((1001\-1000) * 65536)
T}:T{
165536\-231071
T}
T{
1002
T}:T{
100000 + ((1002\-1000) * 65536)
T}:T{
231072\-296607
T}
T{
1100
T}:T{
100000 + ((1100\-1000) * 65536)
T}:T{
6653600\-6719135
T}
.TE
.sp 1
.SS "Subordinate ID Space Planning"
When planning subordinate ID allocation, calculate the maximum number of users the space can accommodate:
.sp
.if n \{\
.RS 4
.\}
.nf
      capacity = (SUB_UID_MAX \- SUB_UID_MIN) / SUB_UID_COUNT
      
.fi
.if n \{\
.RE
.\}
.sp
With default values: (600100000 \- 100000) / 65536 ≈ 9155 users\&.
.sp
For high\-density environments with many users and smaller allocations:
.sp
.if n \{\
.RS 4
.\}
.nf
        SUB_UID_COUNT  4096
        SUB_UID_MIN    100000
        SUB_UID_MAX    10000000
      
.fi
.if n \{\
.RE
.\}
.sp
This gives: (10000000 \- 100000) / 4096 ≈ 2417 users\&.
.RE
.PP
\fBUNSAFE_SUB_UID_DETERMINISTIC_WRAP\fR (boolean)
.RS 4
\fB WARNING: SECURITY RISK \- MAY CAUSE RANGE OVERLAPS AND PRIVILEGE ESCALATION! \fR
.sp
Only effective when
\fBSUB_UID_DETERMINISTIC\fR
is set to
\fIyes\fR\&.
.sp
When set to
\fIyes\fR
(WRAP MODE), allows the deterministic range calculation to wrap around using modulo arithmetic when a UID would overflow the configured subordinate ID space\&. The subordinate ID space is treated as a ring buffer\&.
.sp
\fBWARNING\fR: Range overlaps can lead to container escapes and privilege escalation\&. For example, with
\fBSUB_UID_MIN\fR=100000,
\fBSUB_UID_MAX\fR=200000,
\fBSUB_UID_COUNT\fR=65536, User A (UID 1000) gets range [100000, 165535] and User B (UID 1001) wraps and overlaps with User A\&. User B\*(Aqs container can now access files from User A\*(Aqs containers\&.
.sp
Use
\fBonly\fR
in development, testing, or tightly constrained lab environments\&.
.sp
When set to
\fIno\fR
(default), any arithmetic overflow or range exceeding
\fBSUB_UID_MAX\fR
is a hard error\&. This guarantees non\-overlapping, monotonic allocation\&.
.sp
The default value for
\fBUNSAFE_SUB_UID_DETERMINISTIC_WRAP\fR
is
\fIno\fR\&.
.RE
.PP
\fBSYS_GID_MAX\fR (number), \fBSYS_GID_MIN\fR (number)
.RS 4
Range of group IDs used for the creation of system groups by
\fBuseradd\fR,
\fBgroupadd\fR, or
\fBnewusers\fR\&.
.sp
The default value for
\fBSYS_GID_MIN\fR
(resp\&.
\fBSYS_GID_MAX\fR) is 101 (resp\&.
\fBGID_MIN\fR\-1)\&.
.RE
.PP
\fBSYS_UID_MAX\fR (number), \fBSYS_UID_MIN\fR (number)
.RS 4
Range of user IDs used for the creation of system users by
\fBuseradd\fR
or
\fBnewusers\fR\&.
.sp
The default value for
\fBSYS_UID_MIN\fR
(resp\&.
\fBSYS_UID_MAX\fR) is 101 (resp\&.
\fBUID_MIN\fR\-1)\&.
.RE
.PP
\fBUID_MAX\fR (number), \fBUID_MIN\fR (number)
.RS 4
Range of user IDs used for the creation of regular users by
\fBuseradd\fR
or
\fBnewusers\fR\&.
.sp
The default value for
\fBUID_MIN\fR
(resp\&.
\fBUID_MAX\fR) is 1000 (resp\&. 60000)\&.
.RE
.PP
\fBUMASK\fR (number)
.RS 4
Valeur d\*(Aqinitialisation du masque de permissions\&. S\*(Aqil n\*(Aqest pas pr\('ecis\('e, le masque des permissions sera initialis\('e \(`a 022\&.
.sp
\fBuseradd\fR
and
\fBnewusers\fR
use this mask to set the mode of the home directory they create if
\fBHOME_MODE\fR
is not set\&.
.sp
It is also used by
\fBpam_umask\fR
as the default umask value\&.
.RE
.SH "FICHIERS"
.PP
/etc/passwd
.RS 4
Informations sur les comptes des utilisateurs\&.
.RE
.PP
/etc/shadow
.RS 4
Informations s\('ecuris\('ees sur les comptes utilisateurs\&.
.RE
.PP
/etc/group
.RS 4
Informations sur les groupes\&.
.RE
.PP
/etc/gshadow
.RS 4
Informations s\('ecuris\('ees sur les groupes\&.
.RE
.PP
/etc/login\&.defs
.RS 4
Configuration de la suite des mots de passe cach\('es \(Fo\ \&shadow password\ \&\(Fc\&.
.RE
.PP
/etc/pam\&.d/newusers
.RS 4
PAM configuration for
\fBnewusers\fR\&.
.RE
.PP
/etc/subgid
.RS 4
IDs des groupes subalternes d\*(Aqun utilisateur\&.
.RE
.PP
/etc/subuid
.RS 4
IDs de utilisateurs subalternes d\*(Aqun utilisateur\&.
.RE
.SH "VOIR AUSSI"
.PP
\fBlogin.defs\fR(5),
\fBpasswd\fR(1),
\fBsubgid\fR(5), \fBsubuid\fR(5),
\fBuseradd\fR(8)\&.