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newgrp - Changes primary group identification of a shell process


newgrp [-l] [group] Obsolete Synopsis newgrp [-] [group] Note 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 standards as follows: newgrp: XCU5.0 Refer to the standards(5) reference page for more information about industry standards and associated tags.


-l 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)


group 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 current 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 that default. 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 members of that group can change to that group. [Tru64 UNIX] Only a user with superuser authority can change the primary group of the shell process to one to which that user does not belong. [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 unavailable after the newgrp command finishes.


1. [Tru64 UNIX] The newgrp command is also a built-in command for csh. 2. 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: LANG 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. LC_ALL If set to a non-empty string value, overrides the values of all the other internationalization variables. LC_CTYPE Determines the locale for the interpretation of sequences of bytes of text data as characters (for example, single-byte as opposed to multibyte characters in arguments). LC_MESSAGES Determines the locale for the format and contents of diagnostic messages written to standard error. NLSPATH Determines the location of message catalogues for the processing of LC_MESSAGES.


/etc/group Group names declared on the system /etc/passwd Password file


Commands: csh(1), groups(1), id(1), login(1), Bourne shell sh(1b), POSIX shell sh(1p) Files: group(4), passwd(4) Standards: standards(5)

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