newgrp(1)newgrp(1)NAMEnewgrp - Changes primary group identification of a shell process
SYNOPSISnewgrp [-l] [group]
newgrp [-] [group]
The C shell has a built-in version of the newgrp command. If you are
using the C shell, and want to guarantee that you are using the command
described here, you must specify the full path /usr/bin/newgrp. See
the csh(1) reference page for a description of the built-in command.
Interfaces documented on this reference page conform to industry stan‐
dards as follows:
Refer to the standards(5) reference page for more information about
industry standards and associated tags.
Changes the login environment to what would be expected if the user
logged in again. Changes the login environment to what would be
expected if the user logged in again. (Obsolescent)
A group name from the group database or a non-negative numeric group
ID. Specifies the group ID to which the real and effective group IDs
will be set. If group is a non-negative numeric string and exists in
the group database as a group name, the numeric group ID associated
with that group name will be used as the group ID.
The newgrp command changes the primary group identification of the cur‐
rent shell process to group. You remain logged in and the current
directory is unchanged, but calculations of access permissions to files
are performed with respect to the primary group ID.
If you do not specify group, newgrp changes the group identification
back to that specified for the current user in the /etc/passwd file.
Only exported environment variables retain their values after you
invoke newgrp. Otherwise, variables with a default value are reset to
If a password is required for the specified group, and you are not
listed as a member of that group in the group database, you are
prompted to enter the correct password for that group. If you are
listed as a member of that group, no password is requested. If no
password is required for the specified group, only users listed as mem‐
bers of that group can change to that group.
[Tru64 UNIX] Only a user with superuser authority can change the pri‐
mary group of the shell process to one to which that user does not
[Tru64 UNIX] When you invoke the newgrp command from a shell, the
shell executes the command without forking a new process. Therefore,
the shell you were using when you issued the newgrp command is unavail‐
able after the newgrp command finishes.
[Tru64 UNIX] The newgrp command is also a built-in command for csh.
There is no convenient way to enter a password into the group database.
Use of group passwords is not encouraged because by their very nature
they encourage poor security practices.
If newgrp succeeds in creating a new shell execution environment,
whether or not the group identification was changed successfully, the
exit status will be the exit status of the shell. Otherwise, a non-zero
exit value is returned.
The exit status of newgrp is generally inapplicable.
The following environment variables affect the execution of newgrp:
Provides a default value for the internationalization variables that
are unset or null. If LANG is unset or null, the corresponding value
from the default locale is used. If any of the internationalization
variables contain an invalid setting, the utility behaves as if none of
the variables had been defined. If set to a non-empty string value,
overrides the values of all the other internationalization variables.
Determines the locale for the interpretation of sequences of bytes of
text data as characters (for example, single-byte as opposed to multi‐
byte characters in arguments). Determines the locale for the format
and contents of diagnostic messages written to standard error. Deter‐
mines the location of message catalogues for the processing of LC_MES‐
Group names declared on the system Password file
Commands: csh(1), groups(1), id(1), login(1), Bourne shell sh(1b),
POSIX shell sh(1p)
Files: group(4), passwd(4)