response 1 of 129:

Jul 1 15:36 UTC 1993

The .cshrc file is executed every time you start a C shell, both at login
and when you start it as a subshell (e.g. when you "shell out" from bbs).
It normally contains aliases, i.e. shorthand notations that you wish to
define for commonly used commands.

The .login file is executed only when you log in, not when you start a
subshell, and is executed *after* .cshrc.  It should contain any commands
that you wish to execute every time you log in, including commands that
set "environment variables" which tell applications your terminal type,
execution path, preferred editor, and possibly other things as well.

You can also create a .logout file that is executed when you log out.

Here's a sample .cshrc file that is a shortened version of the one I
used to use when csh was my login shell, with a couple of additions:
------
if ($?prompt) then
    set           history=200
    alias hi      history
    alias tset    '/usr/ucb/tset -s \!* >/tmp/ts.$$ ; source /tmp/ts.$$ ; rm
    /tmp/ts.$$' alias md      mkdir alias rd      rmdir alias dir     ls -l
    alias lf      ls -F alias sane    'stty cooked -cbreak echo erase "^H" kill
    "^U" intr "^C"' alias cd      'chdir \!* ; set prompt="$cwd \! % "'
endif
------
The 'tset' alias facilitates setting your terminal type in your .login
(see below), and the 'alias cd..' command puts your current directory
in your prompt, as well as the current command number (useful when you
invoke the shell history mechanism).

Here's a sample .login:
------
umask  22
set    path=($HOME/bin /usr/local/bin /usr/ucb /bin /usr/bin /usr/games .)
setenv MANPATH '  /usr/local/man:/usr/man'
setenv MAILREADER elm
setenv EDITOR     vi
setenv VISUAL     vi
setenv EXINIT     'source ~/.virc'
setenv NETHACKOPTIONS \
                'name:Brunhilde-V,dogname:Fjord,female,number_pad,nopickup'

stty   intr '^C' kill '^U' erase '^H'
tset   -m 'dialup:?vt102' -m 'su:?vt102' "$TERM"
mesg   y
cd     .
clear
------
The umask command determines the initial protection when you create files.
'22' means 'read & execute permission for all, write permission only for
owner'.

'setenv EXINIT ...' causes the vi editor to execute an initialization file
called .virc in my home directory every time it starts up.

The stty command sets my interrupt, line kill, and erase characters to my
preferences.

The tset command causes me to be prompted for my terminal type when I log
in, taking vt102 as the default if I just hit return.

'cd .' initializes my prompt to contain the current directory and command
number (see the cd alias in .cshrc).

response 3 of 129:

Jul 1 20:53 UTC 1993

Thanks for the tips.  At least I'll have a place to start now.

response 5 of 129:

Oct 10 10:44 UTC 1993

Not immediately.  Your .login file is run only when you log in, so any
changes to it won't take effect until your next session.  Is it ok now?

response 7 of 129:

Oct 11 01:51 UTC 1993

I thikn it's working fine now...

response 9 of 129:

Apr 25 05:11 UTC 1994

 aliases go in the .cshrc file. 
if ($?prompt) then
    set           history=200
    alias j       jove
 alias callbook  telnet electra.cs.buffalo.edu 2000
alias hi      history
    alias d       du
    alias free    df
    alias c      cal
    alias pi      pico
    alias pm      pine
alias a bye
alias p bbs
alias l   lynx
    alias z       elm
    alias a       logout
    alias hi      history
    alias g       backgammon
    alias bye     logout
    alias p       bbs
    alias fo      fortune
alias sun         telnet paladine.hacks.arizona.edu
alias e       exit   
alias ch      change
unsetenv TERMCAP
set term=vt100
endif
 This is my file. enjoy.

response 11 of 129:

Apr 25 06:20 UTC 1994

Every copy of csh always sources commands from .cshrc when it starts,
even subshells, even non-interactive shells.
If it is a login shell it follow that by sourcing .login

response 13 of 129:

Apr 25 10:16 UTC 1994

It takes the file in question as a list of csh commands to be executed -
a script, in other words.

response 15 of 129:

Apr 26 07:23 UTC 1994

In unix, if you give command "foo" and there is a file "foo" on your path,
it will execute  it.  If it is a shell script, this means it will start a 
subshell to take its command from foo. Thus if your "foo" script
changed an environment variable or a shell variable, it would lose effect
when the shell terminated at the end of "foo". The parent shell's
variables are not affected by commands executed by a child.

There is only one way around this limitation. The "source" command.
This command is built into the shell and causes the shell itself to
temporarily take its commands (its source) from a specified file.

Since .cshrc and .login files tend to want to change variables and stuff,
they must be "sourced" rather than executed. That's why I use the
terminology. csh "sources" the .cshrc and .login files, rather than
executing them.  

This distinction (when not properly made) confuses all newbie shell scripters.
So it turns out to be fairly important. I hope I explained it clearly.

response 19 of 129:

Apr 26 14:34 UTC 1994

Re #17:  Hmm, perhaps you're right.  I'd always assumed the environment
in DOS was a chunk of memory independent of COMMAND.COM, but now that I
think of it, you can set its size when you run COMMAND.COM, so it
makes sense that each instance has its own environment.

response 21 of 129:

Apr 27 00:43 UTC 1994

Oops.  But there's a facility in sh with almost the same effect, namely
using a dot (period) as a command with a shellscript as its argument.
The script has to be slightly special, if I recall, as it sees the
calling shell's (or script's) arguments rather than any you may have tried
to provide on the command line.  I don't know whether source works this
way.

response 23 of 129:

Apr 27 18:03 UTC 1994

So you get backward environment-passing at the expense of forward
parameter-passing.  Often a very attractive trade - but sometimes I've
wanted *both*.