Customizing a User's Work Environment
Part of setting up a user's home directory is providing user initialization files
for the user's login shell. A user initialization file is a shell script that
sets up a work environment for a user after the user logs in
to a system. Basically, you can perform any task in a user initialization
file that you can do in a shell script. However, a user initialization
file's primary job is to define the characteristics of a user's work environment,
such as a user's search path, environment variables, and windowing environment. Each login
shell has its own user initialization file or files, which are listed in
the following table.
Table 4-14 User Initialization Files for Bourne, C, and Korn Shells
Shell |
User Initialization File |
Purpose |
|---|
Bourne |
$HOME/.profile |
Defines the user's
environment at login |
C |
$HOME/.cshrc |
Defines the user's environment for all C shells
and is invoked after login shell |
|
$HOME/.login |
Defines the user's environment at login |
Korn |
$HOME/.profile
|
Defines the user's environment at login |
|
$HOME/$ENV |
Defines user's environment at login in
the file and is specified by the Korn shell's ENV environment variable |
The Solaris environment provides default user initialization files for each shell in the
/etc/skel directory on each system, as shown in the following table.
Table 4-15 Default User Initialization Files
Shell |
Default File |
|---|
C |
/etc/skel/local.login |
|
/etc/skel/local.cshrc |
Bourne or Korn |
/etc/skel/local.profile |
You can use these files as a starting point and modify them to
create a standard set of files that provide the work environment common to
all users. Or, you can modify these files to provide the working environment
for different types of users. Although you cannot create customized user initialization files
with the Users tool, you can populate a user's home directory with user
initialization files located in a specified “skeleton” directory. You can do this by
creating a user template with the User Templates tool and specifying a skeleton
directory from which to copy user initialization files.
For step-by-step instructions on how to create sets of user initialization files for different
types of users, see How to Customize User Initialization Files.
When you use the Users tool to create a new user account
and select the create home directory option, the following files are created, depending on
which login shell is selected.
Table 4-16 Files Created by Users Tool When Adding a User
Shell |
Files Created |
|---|
C |
The /etc/skel/local.cshrc and the /etc/skel/local.login files
are copied into the user's home directory and are renamed .cshrc and
.login, respectively. |
Bourne and Korn |
The /etc/skel/local.profile file is copied into the user's home directory
and renamed .profile. |
If you use the useradd command to add a new user account and
specify the /etc/skel directory by using the -k and -m options, all three
/etc/skel/local* files and the /etc/skel/.profile file are copied into the user's home directory.
At this point, you need to rename them to whatever is appropriate for
the user's login shell.
Using Site Initialization Files
The user initialization files can be customized by both the administrator and the
user. This important feature can be accomplished with centrally located and globally distributed
user initialization files, called site initialization files. Site initialization files enable you to continually introduce new
functionality to the user's work environment, while enabling the user to customize the
user's initialization file.
When you reference a site initialization file in a user initialization file, all
updates to the site initialization file are automatically reflected when the user logs
in to the system or when a user starts a new shell.
Site initialization files are designed for you to distribute site-wide changes to users' work
environments that you did not anticipate when you added the users.
You can customize a site initialization file the same way that you
customize a user initialization file. These files typically reside on a server, or
set of servers, and appear as the first statement in a user initialization
file. Also, each site initialization file must be the same type of shell
script as the user initialization file that references it.
To reference a site initialization file in a C-shell user initialization file, place a
line similar to the following at the beginning of the user initialization file:
source /net/machine-name/export/site-files/site-init-file
To reference a site initialization file in a Bourne-shell or Korn-shell user initialization
file, place a line similar to the following at the beginning of the
user initialization file:
. /net/machine-name/export/site-files/site-init-file
Avoiding Local System References
You should not add specific references to the local system in the user
initialization file. You want the instructions in a user initialization file to be
valid regardless of which system the user logs into.
For example:
To make a user's home directory available anywhere on the network, always refer to the home directory with the variable $HOME. For example, use $HOME/bin instead of /export/home/username/bin. The $HOME variable works when the user logs in to another system and the home directories are automounted.
To access files on a local disk, use global path names, such as /net/system-name/directory-name. Any directory referenced by /net/system-name can be mounted automatically on any system on which the user logs in, assuming the system is running AutoFS.
Shell Features
The following table lists basic shell features that each shell provides, which can
help you determine what you can and can't do when creating user initialization files
for each shell.
Table 4-17 Basic Features of Bourne, C, and Korn Shells
Feature |
Bourne |
C |
Korn |
|---|
Known as the standard shell in UNIX |
Applicable |
N/A |
N/A |
Compatible syntax with Bourne
shell |
- |
N/A |
Applicable |
Job control |
Applicable |
Applicable |
Applicable |
History list |
N/A |
Applicable |
Applicable |
Command-line editing |
N/A |
Applicable |
Applicable |
Aliases |
N/A |
Applicable |
Applicable |
Single-character abbreviation for login directory |
N/A |
Applicable |
Applicable |
Protection from overwriting (noclobber) |
N/A |
Applicable |
Applicable |
Setting to
ignore Control-D (ignoreeof) |
N/A |
Applicable |
Applicable |
Enhanced cd command |
N/A |
Applicable |
Applicable |
Initialization file separate from .profile |
N/A |
Applicable |
Applicable |
Logout file |
N/A |
Applicable |
N/A |
Shell Environment
A shell maintains an environment that includes a set of variables defined by
the login program, the system initialization file, and the user initialization files. In
addition, some variables are defined by default.
A shell can have two types of variables:
Environment variables – Variables that are exported to all processes spawned by the shell. Their settings can be seen with the env command. A subset of environment variables, such as PATH, affects the behavior of the shell itself.
Shell (local) variables – Variables that affect only the current shell. In the C shell, a set of these shell variables have a special relationship to a corresponding set of environment variables. These shell variables are user, term, home, and path. The value of the environment variable counterpart is initially used to set the shell variable.
In the C shell, you use the lowercase names with the set command
to set shell variables. You use uppercase names with the setenv command to
set environment variables. If you set a shell variable, the shell sets the
corresponding environment variable. Likewise, if you set an environment variable, the corresponding shell variable
is also updated. For example, if you update the path shell variable with
a new path, the shell also updates the PATH environment variable with the
new path.
In the Bourne and Korn shells, you can use the uppercase variable
name equal to some value to set both shell and environment variables. You
also have to use the export command to activate the variables for any subsequently
executed commands.
For all shells, you generally refer to shell and environment variables by their
uppercase names.
In a user initialization file, you can customize a user's shell environment by
changing the values of the predefined variables or by specifying additional variables. The
following table shows how to set environment variables in a user initialization file.
Table 4-18 Setting Environment Variables in a User Initialization File
Shell Type |
Line to Add to the User Initialization File |
|---|
C shell
|
setenv VARIABLE value Example: setenv MAIL /var/mail/ripley |
Bourne or Korn shell |
VARIABLE=value; export VARIABLE Example: MAIL=/var/mail/ripley;export MAIL |
The following table describes environment variables and shell variables that you might want to
customize in a user initialization file. For more information about variables that are
used by the different shells, see the sh(1), ksh(1), or csh(1) man pages.
Table 4-19 Shell and Environment Variable Descriptions
Variable |
Description |
|---|
CDPATH,
or cdpath in the C shell |
Sets a variable used by the
cd command. If the target directory of the cd command is specified as
a relative path name, the cd command first looks for the target directory in
the current directory (“.”). If the target is not found, the path names
listed in the CDPATH variable are searched consecutively until the target directory is
found and the directory change is completed. If the target directory is not
found, the current working directory is left unmodified. For example, the CDPATH variable
is set to /home/jean, and two directories exist under /home/jean, bin, and
rje. If you are in the /home/jean/bin directory and type cd rje, you
change directories to /home/jean/rje, even though you do not specify a full path. |
history |
Sets
the history for the C shell. |
HOME, or home in the C shell |
Sets the
path to the user's home directory. |
LANG |
Sets the locale. |
LOGNAME |
Defines the name
of the user currently logged in. The default value of LOGNAME is set
automatically by the login program to the user name specified in the
passwd file. You should only need to refer to, not reset, this variable.
|
LPDEST |
Sets the user's default printer. |
MAIL |
Sets the path to the
user's mailbox. |
MANPATH |
Sets the hierarchies of man pages that are available. |
PATH, or
path in the C shell |
Specifies, in order, the directories that the
shell searches to find the program to run when the user types a
command. If the directory is not in the search path, users must type
the complete path name of a command. As part of the login process,
the default PATH is automatically defined and set as specified in .profile (Bourne
or Korn shell) or .cshrc (C shell). The order of the search
path is important. When identical commands exist in different locations, the first command
found with that name is used. For example, suppose that PATH is defined
in Bourne and Korn shell syntax as PATH=/bin:/usr/bin:/usr/sbin:$HOME/bin and a file named sample resides
in both /usr/bin and /home/jean/bin. If the user types the command sample
without specifying its full path name, the version found in /usr/bin is used. |
prompt |
Defines
the shell prompt for the C shell. |
PS1 |
Defines the shell prompt for
the Bourne or Korn shell. |
SHELL, or shell in the C shell
|
Sets the default shell used by make, vi, and other tools. |
TERMINFO |
Specifies the
path name for an unsupported terminal that has been added to the terminfo
file. Use the TERMINFO variable in either the /etc/profile or /etc/.login file. When
the TERMINFO environment variable is set, the system first checks the TERMINFO path
defined by the user. If the system does not find a definition for
a terminal in the TERMINFO directory defined by the user, it searches the
default directory, /usr/share/lib/terminfo, for a definition. If the system does not find
a definition in either location, the terminal is identified as “dumb.” |
TERM, or term
in the C shell |
Defines the terminal. This variable should be reset
in either the /etc/profile or /etc/.login file. When the user invokes an editor,
the system looks for a file with the same name that is defined
in this environment variable. The system searches the directory referenced by TERMINFO to
determine the terminal characteristics. |
TZ |
Sets the time zone. The time zone is
used to display dates, for example, in the ls -l command. If
TZ is not set in the user's environment, the system setting is used.
Otherwise, Greenwich Mean Time is used. |
The PATH Variable
When the user executes a command by using the full path, the shell
uses that path to find the command. However, when users specify only a
command name, the shell searches the directories for the command in the order
specified by the PATH variable. If the command is found in one of
the directories, the shell executes the command.
A default path is set by the system. However, most users modify
it to add other command directories. Many user problems related to setting up
the environment and accessing the correct version of a command or a tool
can be traced to incorrectly defined paths.
Setting Path Guidelines
Here are some guidelines for setting up efficient PATH variables:
If security is not a concern, put the current working directory (.) first in the path. However, including the current working directory in the path poses a security risk that you might want to avoid, especially for superuser.
Keep the search path as short as possible. The shell searches each directory in the path. If a command is not found, long searches can slow down system performance.
The search path is read from left to right, so you should put directories for commonly used commands at the beginning of the path.
Make sure that directories are not duplicated in the path.
Avoid searching large directories, if possible. Put large directories at the end of the path.
Put local directories before NFS mounted directories to lessen the chance of “hanging” when the NFS server does not respond. This strategy also reduces unnecessary network traffic.
Setting a User's Default Path
This is an example of how to set a user's default path.
The following examples show how to set a user's default path to include
the home directory and other NFS mounted directories. The current working directory is
specified first in the path. In a C-shell user initialization file, you would
add the following:
set path=(. /usr/bin $HOME/bin /net/glrr/files1/bin)
In a Bourne-shell or Korn-shell user initialization file, you would add the following:
PATH=.:/usr/bin:/$HOME/bin:/net/glrr/files1/bin
export PATH
Locale Variables
The LANG and LC environment variables specify the locale-specific conversions and conventions for
the shell. These conversions and conventions include time zones, collation orders, and formats of
dates, time, currency, and numbers. In addition, you can use the stty command
in a user initialization file to indicate whether the terminal session will support
multibyte characters.
The LANG variable sets all possible conversions and conventions for the given locale.
You can set various aspects of localization separately through these LC variables: LC_COLLATE,
LC_CTYPE, LC_MESSAGES, LC_NUMERIC, LC_MONETARY, and LC_TIME.
The following table describes some of the values for the LANG and
LC environment variables.
Table 4-20 Values for LANG and LC Variables
Value |
Locale |
|---|
de_DE.ISO8859-1 |
German |
en_US.UTF-8 |
American English (UTF-8) |
es_ES.ISO8859-1 |
Spanish |
fr_FR.ISO8859-1 |
French |
it_IT.ISO8859-1 |
Italian |
ja_JP.eucJP |
Japanese (EUC) |
ko_KR.EUC |
Korean (EUC) |
sv_SE.ISO8859-1 |
Swedish |
zh_CN.EUC |
Simplified Chinese (EUC) |
zh_TW.EUC |
Traditional Chinese (EUC) |
For more information on supported locales, see the International Language Environments Guide.
Example 4-1 Setting the Locale Using the LANG Variables
The following examples show how to set the locale by using the LANG
environment variables. In a C-shell user initialization file, you would add the following:
setenv LANG de_DE.ISO8859-1
In a Bourne-shell or Korn-shell user initialization file, you would add the following:
LANG=de_DE.ISO8859-1; export LANG
Default File Permissions (umask)
When you create a file or directory, the default file permissions assigned to
the file or directory are controlled by the user mask. The user mask is set
by the umask command in a user initialization file. You can display the
current value of the user mask by typing umask and pressing Return.
The user mask contains the following octal values:
The first digit sets permissions for the user
The second digit sets permissions for group
The third digit sets permissions for other, also referred to as world
Note that if the first digit is zero, it is not displayed.
For example, if the user mask is set to 022, 22 is displayed.
To determine the umask value you want to set, subtract the value of
the permissions you want from 666 (for a file) or 777 (for
a directory). The remainder is the value to use with the umask command. For
example, suppose you want to change the default mode for files to
644 (rw-r--r--). The difference between 666 and 644 is 022, which is the value
you would use as an argument to the umask command.
You can also determine the umask value you want to set by using
the following table. This table shows the file and directory permissions that are
created for each of the octal values of umask.
Table 4-21 Permissions for umask Values
umask Octal Value |
File Permissions |
Directory
Permissions |
|---|
0 |
rw- |
rwx |
1 |
rw- |
rw- |
2 |
r-- |
r-x |
3 |
r-- |
r-- |
4 |
-w- |
-wx |
5 |
-w- |
-w- |
6 |
--x |
--x |
7 |
--- (none) |
--- (none) |
The following line in a user initialization file sets the default file permissions
to rw-rw-rw-.
umask 000
User and Site Initialization Files Examples
The following sections provide examples of user and site initialization files that you
can use to start customizing your own initialization files. These examples use system
names and paths that you need to change for your particular site.
Example 4-2 The .profile File
(Line 1) PATH=$PATH:$HOME/bin:/usr/local/bin:/usr/ccs/bin:.
(Line 2) MAIL=/var/mail/$LOGNAME
(Line 3) NNTPSERVER=server1
(Line 4) MANPATH=/usr/share/man:/usr/local/man
(Line 5) PRINTER=printer1
(Line 6) umask 022
(Line 7) export PATH MAIL NNTPSERVER MANPATH PRINTER
Defines the user's shell search path
Defines the path to the user's mail file
Defines the user's Usenet news server
Defines the user's search path for man pages
Defines the user's default printer
Sets the user's default file creation permissions
Sets the listed environment variables
Example 4-3 The .cshrc File
(Line 1) set path=($PATH $HOME/bin /usr/local/bin /usr/ccs/bin)
(Line 2) setenv MAIL /var/mail/$LOGNAME
(Line 3) setenv NNTPSERVER server1
(Line 4) setenv PRINTER printer1
(Line 5) alias h history
(Line 6) umask 022
(Line 7) source /net/server2/site-init-files/site.login
Defines the user's shell search path.
Defines the path to the user's mail file.
Defines the user's Usenet news server.
Defines the user's default printer.
Creates an alias for the history command. The user needs to type only h to run the history command.
Sets the user's default file creation permissions.
Sources the site initialization file.
Example 4-4 Site Initialization File
The following shows an example site initialization file in which a user can
choose a particular version of an application.
# @(#)site.login
main:
echo "Application Environment Selection"
echo ""
echo "1. Application, Version 1"
echo "2. Application, Version 2"
echo ""
echo -n "Type 1 or 2 and press Return to set your
application environment: "
set choice = $<
if ( $choice !~ [1-2] ) then
goto main
endif
switch ($choice)
case "1":
setenv APPHOME /opt/app-v.1
breaksw
case "2":
setenv APPHOME /opt/app-v.2
endsw
This site initialization file could be referenced in a user's .cshrc file
(C shell users only) with the following line:
source /net/server2/site-init-files/site.login
In this line, the site initialization file is named site.login and is located
on a server named server2. This line also assumes that the automounter is
running on the user's system.
