On Sun, 2008-04-06 at 02:11 +0100, Ned Slider wrote: > Hi List, > > I've just drafted a FAQ/mini-HOWTO on becoming root as this is a topic I > see come up time and time again. > > Perhaps someone with a reasonable understanding could check it for > technical correctness, and if anyone would like to offer comments/feedback?? > > Any suggestions as to where might be an appropriate home for this on the > Wiki? > > Regards, > > Ned > (attached below) > > -------------------- > > *How to become root* > > Many commands can only be run as the root user so to run these commands > we need to become "root". To do this, we use the su command (substitute > user). > > The su command takes the following format: > > su - <user> > > but most commonly we will use su to become the root user: > > su - root > > If no username is specified, then the root user is assumed, so the above > is often shortened to: > > su > > or > > su - > > but the above are NOT the same thing. > > Often a user will become root using just 'su', try to run a command (eg, > ifconfig), and get a 'command not found' error: > > su > Password: > ifconfig > bash: ifconfig: command not found > > The reason is that regular system users and the root user have different > PATHS (you can view a users PATH with 'echo $PATH'). When you type a > Linux command, the shell with search the users PATH to try to locate the > command to run. It starts searching each directory on the PATH until a > match is found. Commands for regular users are mostly located in > /usr/local/bin, /usr/bin, and /bin. However, root commands are mostly > located in /usr/local/sbin, /usr/sbin, and /sbin and root's PATH > reflects this difference. > > When you become root by using 'su -', you also adopt root's PATH whereas > using just 'su' retains the original users PATH, hence why becoming root > using just 'su' and trying to run a command located in /usr/local/sbin, > /usr/sbin, or /sbin results in a 'command not found' error. > > So you either need to specify the full PATH to the command if you just > used 'su' (eg, /sbin/ifconfig) or use the full 'su -'. Ever noticed in Red Hats Docs the full path to the command in question?? machine at you]#/usr/sbin/mii-tool And boy is Ubunto and Debian confusing. It sounds good. And it is better than the Debian way I think. just my two cents. > > _______________________________________________ > CentOS-docs mailing list > CentOS-docs at centos.org > http://lists.centos.org/mailman/listinfo/centos-docs -- ~/john OpenPGP Sig:BA91F079