There isn't a -pthread option on BSD, it's spelled -lpthread :-)
Are you sure?
$ uname FreeBSD $ gcc -pthread gcc: No input files specified $ gcc -pthreads gcc: unrecognized option `-pthreads' gcc: No input files specified $ gcc -lpthread /usr/libexec/elf/ld: cannot find -lpthread $ locate libpthread /usr/compat/linux/lib/libpthread-0.9.so /usr/compat/linux/lib/libpthread.so.0
libpthread doesn't exist on most FreeBSD systems, unless (as above) as part of the linux compatibility runtime, used when running linux executables). Instead the pthread_* functions are contained in a reentrant version of libc: libc_r.
For GCC 3 on FreeBSD when -pthread is given then the linker is passed -lc_r (to link to the reentrant version of libc) and when -pthread is absent the linker is passed -lc (the non-reentrant libc).
(It's slightly complicated by the absence/presence of -pg, as there are also profiling versions of libc, so you end up with one of libc, libc_r, libc_p, or libc_r_p)
The behaviour seems to be the same on GCC 2.95 though I haven't checked the source to confirm that.
You're right! Serves me right for relying on memory, I take it all back, -pthread is the option to use. Thanks! John.