Static ln (sln) and static sync (ssync)
are useful when things go wrong. The primary use of sln (to
repair incorrect symlinks in /lib after a poorly orchestrated
upgrade) is no longer a major concern now that the ldconfig
program (usually located in /usr/sbin) exists and can act as a
guiding hand in upgrading the dynamic libraries. Static sync is
useful in some emergency situations. Note that these need not be
statically linked versions of the standard ln and sync,
but may be.
The ldconfig binary is optional for /sbin since a site
may choose to run ldconfig at boot time, rather than only when
upgrading the shared libraries. (It's not clear whether or not it is
advantageous to run ldconfig on each boot.) Even so, some
people like ldconfig around for the following (all too common)
situation:
I've just removed /lib/<file>.
I can't find out the name of the library because ls is
dynamically linked, I'm using a shell that doesn't have ls
built-in, and I don't know about using "echo *" as a
replacement.
I have a static sln, but I don't know what to call the link.
Miscellaneous:
{ ctrlaltdel, kbdrate }
So as to cope with the fact that some keyboards come up with such a high
repeat rate as to be unusable, kbdrate may be installed in
/sbin on some systems.
Since the default action in the kernel for the Ctrl-Alt-Del key
combination is an instant hard reboot, it is generally advisable to
disable the behavior before mounting the root filesystem in read-write
mode. Some init suites are able to disable Ctrl-Alt-Del, but
others may require the ctrlaltdel program, which may be
installed in /sbin on those systems.