lassie% ls
add2.c       avg3.c       hello.c      inchtocm.c
add2f.c      day1         hello2.c     junk.ps

lassie% cc201 hello.c

lassie% ls
a.out*       add2f.c      day1         hello2.c     junk.ps
add2.c       avg3.c       hello.c      inchtocm.c

lassie% a.out
Hello world.
lassie% 



lassie% cc hello2.c
hello2.c:8: genlib.h: No such file or directory

lassie% cc201 hello2.c

lassie% a.out
Mork says: Hello world.
World says: Hello back.
lassie%