getcwd() and friends.

[Felix Lee]

In article <3675 at ficc.uu.net> peter at ficc.uu.net (Peter da Silva) writes:
>One thing that really would make things a lot easier would be a fchdir()
>call, that took a file descriptor and tried to chdir to it. All the info
>that UNIX needs for the chdir is available via the fd.

This would open up holes with chroot(), but anyway...

You need another open() mode, O_EXEC, open for execution.  Then you
could fchdir(), fexecve(), and so forth.  With a little work, you
could then replace all the standard system calls with library routines
that call the corresponding f-function.  Then knowledge of path names
would be localized to the open() function (making it easier to add
file access hooks).

flink(), funlink(), and frename() are problematical because you also
need descriptors to the directories involved, unless you attach
knowledge of name and location to file descriptors.

Probably not worth the effort.  Now if you want to come up with a more
powerful model of data storage that lets you layer Unix filesystem
semantics on top of it...

(Aside from all that, pushdir()/popdir() routines would be handy.)
--
Felix Lee	flee at shire.cs.psu.edu	*!psuvax1!shire!flee