Jim Stapleton wrote: > FreeBSD > ======================================== > [sjss@elrond ~/dev/numbench]$ gcc numbench.c > /var/tmp//ccnZ4l7C.o(.text+0x155c): In function `loop_calibrate': > : undefined reference to `nanotime' > /var/tmp//ccnZ4l7C.o(.text+0x15b6): In function `loop_calibrate': > : undefined reference to `nanotime' > /var/tmp//ccnZ4l7C.o(.text+0x15ec): In function `iterbenchI': > : undefined reference to `nanotime' > /var/tmp//ccnZ4l7C.o(.text+0x165d): In function `iterbenchI': > : undefined reference to `nanotime' > /var/tmp//ccnZ4l7C.o(.text+0x1694): In function `iterbenchF': > : undefined reference to `nanotime' > /var/tmp//ccnZ4l7C.o(.text+0x1705): more undefined references to > `nanotime' follow > ======================================== On FreeBSD this is a kernel mode interface, not available to userspace. That is why the manpage is in section 9. So you can't call this function from a normal program. > Cygwin: > ======================================== > $ gcc numbench.c -lc -lm > /cygdrive/c/DOCUME~1/STAPLE~1/LOCALS~1/Temp/ccSqoE54.o:numbench.c:(.text+0x2b4): > undefined reference to `_srandomdev' > /cygdrive/c/DOCUME~1/STAPLE~1/LOCALS~1/Temp/ccSqoE54.o:numbench.c:(.text+0x13ef): > undefined reference to `_nanotime' > /cygdrive/c/DOCUME~1/STAPLE~1/LOCALS~1/Temp/ccSqoE54.o:numbench.c:(.text+0x1445): > undefined reference to `_nanotime' > /cygdrive/c/DOCUME~1/STAPLE~1/LOCALS~1/Temp/ccSqoE54.o:numbench.c:(.text+0x1478): > undefined reference to `_nanotime' > /cygdrive/c/DOCUME~1/STAPLE~1/LOCALS~1/Temp/ccSqoE54.o:numbench.c:(.text+0x14e5): > undefined reference to `_nanotime' > /cygdrive/c/DOCUME~1/STAPLE~1/LOCALS~1/Temp/ccSqoE54.o:numbench.c:(.text+0x1518): > undefined reference to `_nanotime' > /cygdrive/c/DOCUME~1/STAPLE~1/LOCALS~1/Temp/ccSqoE54.o:numbench.c:(.text+0x1585): > more undefined references to `_nanotime' follow > collect2: ld returned 1 exit status > ======================================== Cygwin does not provide the nanotime function. > I tried adding a few libraries that might be useful: -lc -lm -lmd > -lpthread, but with no luck. I figured I'd try to find what library it > is in, but couldn't (strings /lib/* | grep nano; string /usr/lib/* | > grep nano). I could only find nanosleep, and a few other non-nanotime > references. The problem is that you're expecting to be able to use a nonstandard function where it does not exist. I think you need to switch APIs if you want to build your code on these platforms. gettimeofday(2) should give you microsecond resolution and is POSIX standard. Brian
