Path: utzoo!utgpu!jarvis.csri.toronto.edu!mailrus!csd4.milw.wisc.edu!leah!itsgw!steinmetz!crdgw1!uunet!vsi!friedl
From: friedl@vsi.COM (Stephen J. Friedl)
Newsgroups: comp.lang.c
Subject: Re: Re^2: Functions pointers and stuff.
Summary: /proc to the rescue!
Message-ID: <1079@vsi.COM>
Date: 31 Mar 89 03:08:35 GMT
References: <1715@leah.Albany.Edu> <3182@goofy.megatest.UUCP> <301@oha.UUCP> <302@oha.UUCP>
Organization: V-Systems, Inc. -- Santa Ana, CA
Lines: 31

Henry Spencer wrote:
>
> The problem here is the assumption that argv[0] is a full pathname for
> the program.  In general it's not, and finding the binary is not a
> trivial exercise.

In article <302@oha.UUCP>, tony@oha.UUCP (Tony Olekshy) writes:
> Henry is, of course, completely correct, so two things are possible:
> 
>  b) Deliberately make the name of the binary known during the installation
>     process, and check the consistency of this information at run-time.
>     This is an alternative which meets the needs set out in the original
>     posting.

First, ksh provides the full pathname in $_, but this of course can
be fooled.

When Sys V Rel 4 comes out, you'll be able to get a file descriptor
to your own executable with an ioctl on a /proc/##### file, where
##### is your pid.  If there is a symbol table there you will be able
to reliably map a function name to an address at runtime.

/proc is really cool.

     Steve

-- 
Stephen J. Friedl / V-Systems, Inc. / Santa Ana, CA / +1 714 545 6442 
3B2-kind-of-guy   / friedl@vsi.com  / {attmail, uunet, etc}!vsi!friedl

"I do everything in software, even DMA" - Gary W. Keefe (garyk@telxon)