Linux and Unix newgrp command
The newgrp command is used to change the current group ID (GID) during a login session. If a hyphen ("-") is included as an argument, then the user's environment is initialized as though he or she had just logged in; otherwise, the current working environment remains unchanged. newgrp changes the current real group ID to the specified group, or, if no group is specified, to the default group listed in the file /etc/passwd. newgrp also tries to add the group to the user groupset.
If the user is root, he or she will not be prompted for a password.
If the user is not root, he or she will be prompted for a group password if:
- the user does not have a password, but the group does, or if
- the user is not listed as a group member, and the group has a password.
If there is no group password set, and the user is not listed as a member of the group, the user will be denied access.
If there is an entry for the group in the shadowed group password file, /etc/gshadow, then the list of members and the password for this group will be taken from this file. Otherwise, the group entry in /etc/group is used.
newgrp [-] [group]
newgrp makes use of the following files:
|/etc/passwd||User account information.|
|/etc/shadow||Secure user account information.|
|/etc/group||Group account information.|
|/etc/gshadow||Secure group account information.|
Attemts to log in to the group developers.
newgrp - developers
Attemps to log in to the group developers, and, if successful, re-initializes the user environment.
gpasswd — Administer /etc/group and /etc/gshadow.
ksh — The Korn shell command interpreter.
login — Begin a session on a system.
set — Set the value of an environment variable.
sh — The Bourne shell command interpreter.