perf@efd.lth.se (Per Foreby) (02/13/91)
I have written a small perl script which some users get as their login
shell. The general idea is to make the workstation personal, but allow
the owner to `su' to another user. The password file contains entries
like `+user:' for authorized users and `+:::::/perl-script' which
matces all other users.
My approch (in pseudo-perl):
if (getlogin () == $ENV{'USER'})
print ("sorry...");
else
exec (login-shell-from-yellow-pages);
The problem: I can't find any way to distinguish between `su user' and
`su - user'. In c this is simple (*argv[0] == '-'), but perls $0 only
gives me the name of the script.
I fear the problem is without solution, but please surprise me!
--
--
Per Foreby; perf@efd.lth.se; LTH-E, Box 118, S-221 00 LUND, Sweden; 046-107492lwall@jpl-devvax.JPL.NASA.GOV (Larry Wall) (02/13/91)
In article <PERF.91Feb13001253@osiris.efd.lth.se> perf@efd.lth.se (Per Foreby) writes:
: The problem: I can't find any way to distinguish between `su user' and
: `su - user'. In c this is simple (*argv[0] == '-'), but perls $0 only
: gives me the name of the script.
:
: I fear the problem is without solution, but please surprise me!
In 4.0, you can get at this with $^P, the name Perl was invoked by.
There's also $^D to access debug flags, and $^I to access the -i flag,
and I may add $^W to access the -w flag.
Maybe I should add a flag that makes the tokener accept metacharacters
in place of keywords... :-) :-) :-)
Larryallbery@NCoast.ORG (Brandon S. Allbery KB8JRR) (02/18/91)
As quoted from <11418@jpl-devvax.JPL.NASA.GOV> by lwall@jpl-devvax.JPL.NASA.GOV (Larry Wall): +--------------- | In 4.0, you can get at this with $^P, the name Perl was invoked by. | There's also $^D to access debug flags, and $^I to access the -i flag, | and I may add $^W to access the -w flag. | | Maybe I should add a flag that makes the tokener accept metacharacters | in place of keywords... :-) :-) :-) +--------------- I've been thinking about the $^x business, Larry. How about changing the special variables to be normally-named variables in package Perl? That way, the debug flags, for example, might be $Perl'debug_flags instead of $^D. It's more readable --- and, much more importantly, you won't run out of variables. ++Brandon -- Me: Brandon S. Allbery VHF/UHF: KB8JRR on 220, 2m, 440 Internet: allbery@NCoast.ORG Packet: KB8JRR @ WA8BXN America OnLine: KB8JRR AMPR: KB8JRR.AmPR.ORG [44.70.4.88] uunet!usenet.ins.cwru.edu!ncoast!allbery Delphi: ALLBERY
composer@chem.bu.edu (Jeff Kellem) (02/18/91)
In article <1991Feb17.171303.20400@NCoast.ORG> allbery@NCoast.ORG (Brandon S. Allbery KB8JRR) writes: > I've been thinking about the $^x business, Larry. How about changing the > special variables to be normally-named variables in package Perl? That way, > the debug flags, for example, might be $Perl'debug_flags instead of $^D. > It's more readable --- and, much more importantly, you won't run out of > variables. But, for those that are lazy, it's easier to type $^x. ;-} -jeff Jeff Kellem Internet: composer@chem.bu.edu
rbj@uunet.UU.NET (Root Boy Jim) (02/19/91)
allbery@ncoast.ORG (Brandon S. Allbery KB8JRR) writes: >It's more readable -- What are you, some kinda reactionary? -- [rbj@uunet 1] stty sane unknown mode: sane
tneff@bfmny0.BFM.COM (Tom Neff) (02/21/91)
In article <1991Feb17.171303.20400@NCoast.ORG> allbery@ncoast.ORG (Brandon S. Allbery KB8JRR) writes: >I've been thinking about the $^x business, Larry. How about changing the >special variables to be normally-named variables in package Perl? That way, >the debug flags, for example, might be $Perl'debug_flags instead of $^D. >It's more readable --- and, much more importantly, you won't run out of >variables. Naturally, losing the short names would break most existing scripts, BUT I still like the idea of having verbose, descriptive names! They could essentially be aliases for the short forms: $. <-> $Perl'line_num and so forth. New, weird variables might be introduced only in the new form rather than try and scrape up another one character symbol.
allbery@NCoast.ORG (Brandon S. Allbery KB8JRR) (02/23/91)
As quoted from <123269@uunet.UU.NET> by rbj@uunet.UU.NET (Root Boy Jim): +--------------- | allbery@ncoast.ORG (Brandon S. Allbery KB8JRR) writes: | >It's more readable -- | | What are you, some kinda reactionary? +--------------- No, I've been getting (and taking) a lot of grief at work about someone no longer with the company whose coding style was dense, unreadable, and uncommented. (It looked a lot like a verbose APL, if you can imagine such a beast.) ++Brandon -- Me: Brandon S. Allbery VHF/UHF: KB8JRR on 220, 2m, 440 Internet: allbery@NCoast.ORG Packet: KB8JRR @ WA8BXN America OnLine: KB8JRR AMPR: KB8JRR.AmPR.ORG [44.70.4.88] uunet!usenet.ins.cwru.edu!ncoast!allbery Delphi: ALLBERY