2.5.1 Quick Login

Add a "quick login" setup to the top of your .cshrc . As soon as the C shell starts and sets a few essentials, this setup asks whether you want a prompt right away. If you answer yes, it starts another C shell with the -f option (important: this makes the subshell ( 38.4 ) skip your .cshrc so you don't get a loop):

login: 

jerry


Password:
Last login: Tue Jan 21 12:34:56 PST 1985
   ...
Answer y for quick login or RETURN for standard: 

y


For a standard login, type 'exit 77'.
% 

mail bigboss


Subject: 

I'm on my way
Carol, I'm leaving for the meeting now. See you by 10:00.
.


% 
[CTRL-d]


login:

From there, I can run a few quick commands. Typing CTRL-d or exit quits the quick subshell and kills my original login shell, too. If I want to stay logged in on that terminal, I type exit   77 . That makes the quick subshell return an exit status ( 44.7 ) of 77; the test in the .cshrc notices this and continues logging me in, reading the rest of the .cshrc and .login .

Here's the top of the .cshrc file to set that up:

if
 
! $?
 




{ }
 


$< =~
 




kill
 
$$
 




setenv
 

# only do stuff below if this is an interactive shell
if (! $?prompt) goto cshrc_end

# QUICK LOGIN:
if (! $?LOGGEDIN) then
   set path = (/bin /usr/ucb /usr/local/{bin,mh} {/usr,~}/bin .)
   echo -n "Answer y for quick login or RETURN for standard: "
   if ("$<" =~ y*) then
      echo "For a standard login, type 'exit 77'."
      csh -f
      # PLAIN "exit" JUST EXITS .cshrc... THIS IS BRUTAL BUT IT WORKS:
      if ($status != 77) kill -9 $$
   endif
endif

setenv LOGGEDIN yes

     ...
Rest of .cshrc
...

cshrc_end:

CAUTION: Be sure to use an if   ($?prompt) test ( 2.9 ) first to keep this command from being read by noninteractive shells. If you don't, non-interactive shells for jobs like at may hang, waiting for an answer to the "quick login" question - or just be confused and not work.

2.5.2 A Second Alias and Command File

Maybe you have a set of aliases or setup commands that you use only for certain projects. If you don't need that setup every time you log in, you can put the setup commands in a separate file. Make an alias named something like setup that reads the file into your setup shell. Only type setup when you need the extra setup done.

Here's the alias:

~
 
source
 

alias setup 'if (! $?setup) source ~/lib/cshrc2'

and the start of the ~/lib/cshrc2 file:

set setup  # variable to stop re-sourcing

alias foo bar
   ...

The first line in the cshrc2 file sets a shell variable that keeps the setup alias from re-reading the file into this shell. This saves time if you forget that you've already run setup .

2.5.3 Once-a-Day Setup

Maybe there are some commands that you want to run only once a day, the first time you log in. For example, I had a reminder system that showed my calendar for the day, reminded me of birthdays, etc. A test like this in .login handles that:

$date[n]
 

set
 
`...`
 


-e
 

touch
 




unset
 

# Put day name in $date[1], month in $date[2], date in $date[3], etc:
set date=(`date`)
# if today's daily setup file doesn't exist, make it and do stuff:
if (! -e ~/tmp/,setup.$date[3]) then
   touch ~/tmp/,setup.$date[3]
   do_calendar
   ...
Other once-a-day setup
...
endif
unset date

That test uses csh arrays ( 47.5 ) to get today's date and make an empty file in my tmp directory with a name like ,setup.23 . Once a file is created (say, on June 23), then the setup commands won't run again that day. I have a program that periodically removes files named with a comma( , ) ( 23.20 , 23.22 ) so ,setup.23 will be long gone by the next month's twenty-third day. That could also be done from the .logout file ( 3.1 , 3.2 ) .