On Monday 07 January 2008 16:54:54 Bill Anderson wrote: > I think you need to get on a Unix box, and check out the actual > structure. Linux has never followed this path, and holds to the old Unix > structure. I have been working with Unix since 1978, and have been > through a number of file structure changes. > > The point is that symbolic links are used to for backwards compatibility. > > As a side light, a number of the utilities that you mention are now > shell built-ins, which take precedence over the equivalent command. For > example, pwd is a built-in that has the -L and -P options for ksh and > bash. The /usr/bin command does not have these options, and exists for > Bourne shell compatibility. You might also note that under Linux it is > /usr/bin/sh, /usr/bin/ksh, and /bin/bash.
It's worth noting that the filesystem is ruled by the Filesystem Hierarchy Standard, http://www.pathname.com/fhs/pub/fhs-2.3.pdf According to it, /bin must be functioning when no partitions other than / are mounted, and thus can't be a symlink Also, it mandates /bin/sh, even though it might be a symlink to another shell, in most cases that is /bin/bash There is also /usr/bin/sh but that is secondary The same is true for ksh, it is also /bin/ksh as well as /usr/bin/ksh, although both are symlinks to /lib/ast/bin/ksh, which is fine since /lib is also mandatory on the / partition For some unknown reason /bin/csh may be a symlink to /usr/bin/tcsh, so if you're on a distribution that keeps tcsh in /usr you should perhaps not use csh as the root shell, in case you have to do any emergency repairs without filesystems mounted (in SuSE it is in /bin) Anders -- Madness takes its toll -- To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED]
