How secure are shell scripts? (summary)

[Doug Gwyn]

In article <4193 at lib.tmc.edu> jmaynard at thesis1.hsch.utexas.edu (Jay Maynard) writes:
>This is a new one on me. What's /dev/fd supposed to do ...
>where can it be obtained?

"/dev/fd/7" is a handle that returns another available file descriptor
that is a duplicate of the current file descriptor # 7.  (Similarly for
other numbers.  Also, /dev/stdin is often provided as a link to /dev/fd/0,
etc.)  I think this first showed up on Research UNIX 8th Edition.  Other
implementations have been provided, for example 4.4BSD probably will have
this.

It is not generally a good idea to try to install a device driver obtained
from elsewhere, unless you are competent to produce the driver yourself.
In the case of /dev/fd, it is pretty easy to implement for yourself.