i downloaded a tarball for libpcap on compiling it i found an error saying the "lex was not sufficient" and told me to download flex and bison

on installing flex and bison and running libpcap, i found an error again,

"bison: subsidiary program `/usr/local/bin/m4' failed (exit status 1)
make: *** [grammar.c] Error 1
"

(i had previously installed m4)

pls help

i have ubuntu 8.10.

So that would be Ubuntu 8.10 in /usr/bin/ and
/usr/lib/, and then something else in /usr/local/

If you are just practicing compiling it's OK, but
I'd suggest removing the /usr/local/ stuff after
you have seen it installing, and use 'synaptic'
or 'apt-get install <package>' to get some of the
28000 Ubuntu packages.

Then you will have a chance to build a few things
not available from the package manager.

The basic developing packages installs with :
'apt-get install build-essential' , and libpcap :
'apt-get install libpcap0.8-dev'
Also have a look at the "Search" function in Synaptic
to get the actual Ubuntu package name.

'm4' : use the Ubuntu package instead of building
it yourself. The same for flex and bison.

Good luck.
....
EDIT : 'apt-get install ...' must be
'sudo apt-get install ....' in Ubuntu.
....