sh(1) [osf1 man page]
sh(1) General Commands Manual sh(1) NAME
sh - Shell, the standard command language interpreter DESCRIPTION
[Tru64 UNIX] Tru64 UNIX provides two command interpreters with the name sh. The XCU5.0 and POSIX.2 compliant command interpreter sh is available in the file /usr/bin/posix/sh and is described in the sh(1p) reference page. The Bourne shell, historically known as sh, is available in the file /usr/bin/sh and is described in the sh(1b) reference page. [Tru64 UNIX] Your initial, or login, shell is determined by your entry in the file /etc/passwd. This file can be changed only by your sys- tem administrator. You must use whatever procedures are in place at your location to have this entry changed. [Tru64 UNIX] If available on your system, you may use the passwd -s or the chsh commands to change your login shell. Note This option is not available if your site manages passwords through the Network Information Service (NIS) facility. Check with your system administrator. [Tru64 UNIX] Subsequent shells spawned from the initial shell depend on the value in the environment variable BIN_SH. If this variable is set to xpg4, the POSIX shell is started. If this variable is set to svr4, an SVR4 compliant version of the shell is started. If this vari- able is unset, the Bourne shell is started. If this variable is set to any other value, an error is reported and the results are unpre- dictable. See the EXAMPLES section for information on setting this variable. NOTES
[Tru64 UNIX] With Tru64 UNIX Version 4.0 the Korn shell, /usr/bin/ksh is the same as the POSIX shell /usr/bin/posix/sh. RESTRICTIONS
[Tru64 UNIX] The file /etc/shells must include entries for both the POSIX shell /usr/bin/posix/sh and the Bourne shell, /usr/bin/sh. If this file is incorrect, see your system administrator. EXAMPLES
Using the Bourne, Korn, or POSIX shell, to set the variable BIN_SH to use the POSIX/ XCU5.0compliant shell, enter: BIN_SH=xpg4 export BIN_SH Using the Bourne, Korn, or POSIX shell, to set the variable BIN_SH to use the SVR4 compliant shell, enter: BIN_SH=svr4 export BIN_SH Using the Bourne, Korn, or POSIX shell, to unset the variable BIN_SH, enter: unset BIN_SH Using the C/ shell, to set the variable BIN_SH to use the POSIX/XCU5.0 compliant shell, enter: setenv BIN_SH xpg4 Using the C/ shell, to set the variable BIN_SH to use the SVR4 compliant shell, enter: setenv BIN_SH svr4 Using the C/ shell, to unset the variable BIN_SH, enter: unsetenv BIN_SH FILES
User profile. Contains user information, including the login shell name. Contains the names of available and permitted shells. SEE ALSO
Commands: csh(1), ksh(1), Bourne shell sh(1b), POSIX shell sh(1p), passwd(1) Files: passwd(4), shells(4) Standards: standards(5) sh(1)
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newgrp(1) General Commands Manual newgrp(1) NAME
newgrp - Changes primary group identification of a shell process SYNOPSIS
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 com- mand described here, you must specify the full path /usr/bin/newgrp. See the csh(1) reference page for a description of the built-in com- mand. STANDARDS
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. OPTIONS
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) OPERANDS
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. DESCRIPTION
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. NOTES
[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 data- base. Use of group passwords is not encouraged because by their very nature they encourage poor security practices. EXIT STATUS
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. ENVIRONMENT VARIABLES
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 multibyte characters in arguments). Determines the locale for the format and contents of diagnostic messages written to standard error. Determines the location of message catalogues for the processing of LC_MESSAGES. FILES
Group names declared on the system Password file SEE ALSO
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) newgrp(1)