[comp.sys.apollo] start_sh

lau@kings.wharton.upenn.edu (Yan K. Lau) (06/09/90)

In article <1647@ns-mx.uiowa.edu> jlhaferman@l_eld09.icaen.uiowa.edu (Jeffrey Lawrence Haferman) writes:
>From article <144@evtprp0b.UUCP>, by mrt7455@evtprp0b (Michael R Tucker):
>> 
>> Why is start_csh not recommended?  To this point, I have been using the csh
>
>Because you should use "chsh" to change your shell entry in /etc/passwd
>to /bin/csh.  Then /bin/csh will be your default shell, eg. when you
>log in.  So there's no reason to use start_csh (note they are not saying
>don't use c-shell, just don't use start_csh).
>
Does this also apply to start_sh?  The reason I ask is that I have /bin/sh
in /etc/passwd as the default shell.  When I hit the "shell" key or cp /bin/sh
at the command: prompt, I get a Bourne shell but it doesn't read my .profile.
However, if I use /bin/start_sh, my .profile is read.  This happens when I log
on at the DM login: prompt.  If I telnet into an Apollo, and log on, then my
.profile is read.  I know when I telnet, it doesn't read my user_data/startup
file which it does when I login to the DM.  What's the explanation? 


Yan.
   )~  Yan K. Lau    lau@kings.wharton.upenn.edu      The Wharton School
 ~/~   -Sheenaphile-          128.91.11.233       University of Pennsylvania
 /\    God/Goddess/All that is -- the source of love, light and inspiration!

rees@dabo.ifs.umich.edu (Jim Rees) (06/09/90)

start_* are all the same program.  What it does, approximately, is strip off
the 'start_' on arg 0 then look in /bin for a program by that name.  Then it
sets $SHELL to /bin/(shellname) and execs the shell, with arg 0 set to
-(shellname).

The shells look at arg0, and if it starts with '-', they run their
respective startup file (.profile, .login, etc).

So the main function of start_foo is to set arg0 to -foo so you get your
login startup file executed.

It's not needed if you log in the normal (Unix) way, with /bin/login, which
sets arg0 for you.  It's mostly useful if your login shell was started by
something like the DM that doesn't do this.