PATH variable

[Robert Locke]

On Wed, 2004-09-08 at 13:58, Nifty Hat Mitch wrote:
> On Wed, Sep 08, 2004 at 08:02:27AM +0200, Joachim Backes wrote:
> 
> > can somebody tell me where the PATH variable is initially set? I'm
> > sure, not in /etc/profile.
> 
> The strict answer to this is that it is set 
> by init (/sbin/init).
> 
>    PATH=/usr/local/sbin:/sbin:/bin:/usr/sbin:/usr/bin
> 
> Since init is the first process from which all other processes are
> created this is the answer to your question.   
> 
> Once init is running the topic  expands through /etc/inittab processing 
> which includes all the scripts in /etc/init.d.
> 
> One of these steps is especially interesting for users at run level 5.
> 
>    # Run xdm in runlevel 5
>    x:5:respawn:/etc/X11/prefdm -nodaemon
> 
> The first line with code in it resets the path thus:
> 
>    PATH=/sbin:/usr/sbin:/bin:/usr/bin:/usr/X11R6/bin
> 
> Now that a display manager is running it might be reset again.
> For gdm we see this line in /usr/bin/gdm.
> 
>   test -f /etc/profile && . /etc/profile
> 
> /etc/profile does its pathmunge thing....
> and then all these are /etc/profile.d/*.sh so if 
> kerberos is there krb5.sh will modify it again.
> 
> All of this might be interesting because a process launched with a
> quick click from the desktop by the window manager might act
> differently when compared to the same process launched from a shell
> prompt.
> 
> Not to be left out is your shell as defined in /etc/passwd
> (bash, csh, tcsh, ksh, sh, zsh).  Each shell has rules for
> startup and standard files it looks at... often PATH is reset
> there.   The csh and tcsh world is funny because $path  is
> almost equal to $PATH (RTFM).
> 
> 
> -- 
> 	T o m  M i t c h e l l 
> 	Just say no to 74LS73 in 2004
> 
Tom,

I need to contest some of what you are saying....  For one, where do
several of the directories you quote get removed from the $PATH of a
regular user, if I am using the "init" process' $PATH?

So let me quote man bash:

>        PATH   The search path for commands.  It is a colon-separated  list  of
>               directories  in  which the shell looks for commands (see COMMAND
>               EXECUTION below).  The default path is system-dependent, and  is
>               set  by  the administrator who installs bash.  A common value is
>               ‘‘/usr/gnu/bin:/usr/local/bin:/usr/ucb:/bin:/usr/bin:.’’.
>  

In doing a strings of /bin/bash, I notice a string of
"/usr/local/bin:/bin:/usr/bin"...

Using that as a basis, then reading /etc/profile makes sense, when it
adds /sbin, /usr/sbin, and /usr/local/sbin if I am root.  It also adds
/usr/X11R6/bin to the end for anybody....  This seems to match what I
see when I launch either a gnome-terminal or log in via a virtual
console....

I have to admit the thought of this being hard-coded into /bin/bash
bothers me, but....

Any thoughts?

--Rob