Question about progress(1)

Tried compiling from source and it fails as I don't know what to link to. Are there clues in progress.c or progress.h what library to link to?
root@Testing:/usr/src/sbin/camcontrol # cc -o progress progress.c
/usr/lib/crt1.o: In function `_start':
/usr/src/lib/csu/amd64/crt1.c:(.text+0x17b): undefined reference to `main'
cc: error: linker command failed with exit code 1 (use -v to see invocation)
You're trying to compile a working executable without a main() function anywhere in the source, that's not going to work. The progress_*() functions in progress.c are supposed to be used as library functions in camcontrol(8) and the main() function is provided by the main source file camcontrol.c. You need to write your own "driver" program that provides the main() function and calls the progress_*() functions.
Works like a charm. Thanks so much.
root@Testing:~ # git clone /root/progress
Cloning into '/root/progress'...
remote: Counting objects: 17, done.
remote: Compressing objects: 100% (13/13), done.
remote: Total 17 (delta 4), reused 17 (delta 4), pack-reused 0
Unpacking objects: 100% (17/17), done.
root@Testing:~ # cd /root/progress
root@Testing:~/progress # make
echo progress.full: /usr/lib/libc.a  >> .depend
Warning: Object directory not changed from original /root/progress
cc  -O2 -pipe -DSTANDALONE_PROGRESS -D__dead=__dead2 -DSECSPERHOUR=3600 -D_DIAGASSERT=assert   -g -MD  -MF.depend.progress.o -MTprogress.o -std=gnu99 -fstack-protector-strong    -Qunused-arguments  -c progress.c -o progress.o
cc  -O2 -pipe -DSTANDALONE_PROGRESS -D__dead=__dead2 -DSECSPERHOUR=3600 -D_DIAGASSERT=assert   -g -MD  -MF.depend.progressbar.o -MTprogressbar.o -std=gnu99 -fstack-protector-strong    -Qunused-arguments  -c progressbar.c -o progressbar.o
cc -O2 -pipe -DSTANDALONE_PROGRESS -D__dead=__dead2 -DSECSPERHOUR=3600 -D_DIAGASSERT=assert -g -std=gnu99 -fstack-protector-strong -Qunused-arguments  -o progress.full progress.o progressbar.o 
objcopy --only-keep-debug progress.full progress.debug
objcopy --strip-debug --add-gnu-debuglink=progress.debug  progress.full progress
gzip -cn progress.1 > progress.1.gz
root@Testing:~/progress # ls
.depend           progress       progress.o
.depend.progress.o   progress.1       progressbar.c
.depend.progressbar.o   progress.1.gz       progressbar.h
.git           progress.c       progressbar.o
.gitignore       progress.debug       strsuftoll.c
Makefile       progress.full
root@Testing:~/progress # progress
progress: Command not found.
root@Testing:~/progress # ./progress
usage: progress [-ez] [-b buffersize] [-f file] [-l length]
                [-p prefix] cmd [args...]