On Tuesday, May 25, 2010, Daniel Bareiro <[email protected]> wrote: > I'm trying to use tcpdump in OpenBSD 4.6 with a syntax similar to the > following: > > # tcpdump -vvv udp and port 5060 or portrange 10000-2000 -s0 \ > -i eht0 -w eavesdropping_ulaw.dump > > In this case, the interface is em0, but I see that with this tcpdump > version there is no parameter 'portrange'. I'm using a version compiled > with the source code obtained by anoncvs, because I wanted to install > with pkg_add but was not available. I tried as follows, but without > success: > > # tcpdump -vv udp and port 5060 or "port >= 10000 and port <= 20000" -s0 \ >> -i em0 -w eavesdropping_ulaw.dump > tcpdump: syntax error
Repeat after me: options go BEFORE positional arguments. That command line should be written as tcpdump -vv -s0 -i em0 -w eavesdropping_ulaw.dump udp and port 5060 or "port >= 10000 and port <= 20000" GNU libc uses a version of getopt() that reorders the command line to accept options after positional arguments, so you might have gotten used to the broken syntax on Linux systems, but it violates the POSIX standard and can create security and portability bugs. Some programs have to explicitly use _another_ GNU extension to disable the behavior in order to work on such systems. Thanks, GNU! Philip Guenther
