How to run linuxtrack_hello_world.c

[smh809]

Hello I'm studying prgramming using my headtracker trackir natural point. linuxtrack works very well. I want to use your example program 'linuxtrack_hello_world.c' but i think i have some problems... I tried to compile this c file typing "sudo gcc linuxtrack_hello_world.c -o helloworld" and error occur like below

sun@sunTFG:/opt/linuxtrack-0.99.18/share/linuxtrack$ sudo gcc linuxtrack_hello_world.c
/tmp/ccNNHbLa.o: In function intialize_tracking': linuxtrack_hello_world.c:(.text+0xe): undefined reference to linuxtrack_init'
linuxtrack_hello_world.c:(.text+0x21): undefined reference to linuxtrack_explain' linuxtrack_hello_world.c:(.text+0x3e): undefined reference to linuxtrack_get_tracking_state'
linuxtrack_hello_world.c:(.text+0x4b): undefined reference to linuxtrack_explain' /tmp/ccNNHbLa.o: In function main':
linuxtrack_hello_world.c:(.text+0x11f): undefined reference to linuxtrack_get_pose' linuxtrack_hello_world.c:(.text+0x18f): undefined reference to linuxtrack_suspend'
linuxtrack_hello_world.c:(.text+0x19c): undefined reference to linuxtrack_wakeup' linuxtrack_hello_world.c:(.text+0x1b5): undefined reference to linuxtrack_shutdown'
collect2: error: ld returned 1 exit status

Can you help me?