On Wed, 2004-09-08 at 14:13, Robert Locke wrote: > 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 > > ââ/usr/gnu/bin:/usr/local/bin:/usr/ucb:/bin:/usr/bin:.ââ. > > > > 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 > Why would that minimal path bother you? It is designed so that EVERY user has that minimal path, and in practice the processing of a file such as $HOME/.bash_profile adds the user specific additional pathing, and /etc/profile adds /sbin etc for root. This was specifically defined to allow all users access to common user-space commands and to limit system management commands to the admins (root). Files used vary depending on the shell being invoked, but every shell has a similar method for customizing a users path to their needs..
