Depending on whether it is your default login shell, C Shell
looks for one or all three of the following files and executes them
as indicated in the order indicated, if they exist:
- /etc/csh.login
If C Shell is your login shell and this file exists,
it is executed.
- .cshrc
If this file exists in your home (login) directory,
it is executed every time C Shell starts, whether at login or when
C Shell is spawned from another shell.
- .login
If C Shell is your login shell and this file exists
in your home directory, it is executed.
While none of these files is required, if present, they provide
a convenient means for customizing the shell environment to fit
your needs.
Setting Environment and Shell Variables |
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Two kinds of variables can be set in the .cshrc
and .login files:
- Environment variables
These variables are global (used by the login shell
process and any processes spawned by the shell process). They are
usually represented by uppercase letters.
- Shell variables
Shell variables are local (used by the login shell
process only) and are not inherited by spawned processes. They are
usually represented by lowercase letters.
Environment variables are usually defined by using the setenv
command, while shell variables are typically defined by the set
command. However, three of the most commonly used environment variables
- USER, TERM,
and PATH - are automatically
imported to and exported from three corresponding variables -
user, term,
and path. Thus, if you execute:
set path=(/bin/posix /bin /usr/bin) |
the value of the environment variable PATH
also becomes /bin/posix:/bin:/usr/bin
(note the difference in syntax between the two variables).
The commands set
and setenv can
be executed interactively from a terminal, or they can be placed
in the .cshrc
or .login files.
The .cshrc Shell Script File |
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Whenever a C Shell starts during your session, it searches
for the file .cshrc in your home directory
and executes it if it exists. The information in this file is used
to set variables and operating parameters that are local to the
shell process.
Since every C Shell created executes this file, it is customary
to use it for setting shell variables by including set
commands in the file. If the .cshrc file does
not exist in your home directory, HP-UX spawns C Shell using default
values for needed variables.
To verify your current shell environment, execute set.
A listing similar to the following is printed on the display:
[25] % set
argv ()
autologout 15
cwd /users/login_name
history 15
home /users/login_name
ignoreeof ignoreeof
is set for this example
noclobber
prompt [!] %
shell /bin/csh
status 0
term hp2622
path (/bin/posix /bin /usr/bin /usr/local/bin /etc/users/login_name . )
[26] % _ |
Some of the commands commonly used in the .cshrc
file and their meanings are shown in Table 10-1 “.cshrc
File Commands”.
Table 10-1 .cshrc
File Commands
Command | Meaning |
|---|
set ignoreeof | Traps CTRL-D's
to avoid accidental system log off. Use the logout
or exit command. |
set prompt = "[\!] %" | This command causes your C Shell prompt
to be the current event number in square brackets followed by a
percent sign. This is very helpful when using the command history
buffer. |
set history=15 | Sequentially keeps a buffer of your last
(15 in this case) events. |
set savehist=15 | This command saves the last (15 in this
case) events when you log off your system. When you log back onto
your system, the event history is restored. |
set noclobber | This command stops C Shell from overwriting
and destroying the information in an existing file. |
You can suppress execution of the .cshrc
file by using the -f
option in the csh
command as follows:
The .login Shell Script File |
|
When you activate C Shell by logging onto the system, C Shell
looks for the shell script file .login
in your home directory and executes it if it exists. This shell
script file contains global commands, variables,
and parameters that you want executed or
set up automatically at the beginning of your session. Some of the
commonly used commands you might want to include in this file and
their meanings are shown below. The term login_name
refers to your login name.
- setenv TERM hp2622
Sets the system variable TERM
to recognize the HP 2622 as your terminal.
- setenv TZ MST7MDT
This command sets the time zone variable. The example
specifies U.S. Mountain Standard Time/Mountain Daylight Savings
Time Zone.
- setenv PATH /bin/posix:/bin:/usr/bin:/usr/local/bin:/etc:/users/login_name:.
This command sets the search pattern the system
uses for finding commands.
- set mail=/usr/mail/login_name
Required to receive mail for HP-UX.
- alias h history
Make the character h
an alias for your command history file.
- alias bye logout
For some, bye
is easier to remember than logout
as a session termination order.
- news | more
Pipe the news through more.
Printable version
