lassie% ls
add2.c       ave2f.c      greeting.c   hello.txt    inchtocm.c
add2f.c      cmtofeet.c   hello.c      hello2.c

lassie% cc201 hello.c
cc -I /home/faculty/chang/pub/cs201/xwindows hello.c -L /home/faculty/chang/pub/cs201/xwindows -lcs201x -lX11 -lm

lassie% ls
a.out*       add2f.c      cmtofeet.c   hello.c      hello2.c
add2.c       ave2f.c      greeting.c   hello.txt    inchtocm.c

lassie% a.out
Hello, world.