Basic Linux command line question Post: 302993066

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Top Forums UNIX for Beginners Questions & Answers Basic Linux command line question Post 302993066 by drysdalk on Monday 6th of March 2017 12:19:17 PM

03-06-2017

Registered User

Hi,

OK, there are various things going here that perhaps need explaining. About the simplest way I can think of tackling your questions is to start with explaining what each of these commands actually does, which might help you understand what you're seeing a bit better.

pwd
This command will print out what's called your current working directory. Your working directory is the directory in the filesystem that you're in at the moment. You change directories with the..

cd
command. cd changes directories, and nothing else. So it's the command you use to change your working directory, and navigate around the filesystem.

su
The switch user command. Nearly always used as a regular user to switch to assume the permissions of the root user. root is the super-user account - that is, the account on a UNIX system that (usually) has full access to all directories and parts of the system, and has permission to run all commands.

Next, I think it would be helpful for you to realise there's a clear distinction between users and directories. Broadly speaking, every user on a UNIX system has one directory on the system reserved for their own use, called their home directory. Typing cd on its own will take you back to this home directory in almost all circumstances. But this home directory needn't have the same name as the user, and can be anything at all. Likewise, any directory on the system can take any name. Every directory on the filesystem will be owned by one particular user and one particular group.

Now, when you use su, the default behaviour will be to leave you in whatever directory you happen to be in at the time, rather than to switch you to the home directory of the user you're wanting to become. If you want it to do that (and more besides), try using the syntax su - instead. This will execute the full login environment of the user you're switching to, and so you will find your current working directory will change to their home directory.

Anyway, hope all this helps you to understand a bit more clearly what's going on here.

drysdalk

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LEARN ABOUT FREEBSD

pam_chroot

PAM_CHROOT(8)						    BSD System Manager's Manual 					     PAM_CHROOT(8)

NAME

     pam_chroot -- Chroot PAM module

SYNOPSIS

     [service-name] module-type control-flag pam_chroot [arguments]

DESCRIPTION

     The chroot service module for PAM chroots users into either a predetermined directory or one derived from their home directory.  If a user's
     home directory as specified in the passwd structure returned by getpwnam(3) contains the string ``/./'', the portion of the directory name to
     the left of that string is used as the chroot directory, and the portion to the right will be the current working directory inside the chroot
     tree.  Otherwise, the directories specified by the dir and cwd options (see below) are used.

     also_root	Do not hold user ID 0 exempt from the chroot requirement.

     always	Report a failure if a chroot directory could not be derived from the user's home directory, and the dir option was not specified.

     cwd=directory
		Specify the directory to chdir(2) into after a successful chroot(2) call.

     dir=directory
		Specify the chroot directory to use if one could not be derived from the user's home directory.

SEE ALSO

     pam.conf(5), pam(8)

AUTHORS

     The pam_chroot module and this manual page were developed for the FreeBSD Project by ThinkSec AS and NAI Labs, the Security Research Division
     of Network Associates, Inc. under DARPA/SPAWAR contract N66001-01-C-8035 (``CBOSS''), as part of the DARPA CHATS research program.

BSD
								 February 10, 2003							       BSD