umbc9% ls
hello.c    oops.txt
umbc9% cp ~chang/pub/cs201/cc201 ~/bin
umbc9% ls
bin       hello.c   oops.txt
umbc9% cat bin
#!/bin/csh -f
cc -I ~chang/pub/cs201/xwindows $* -L ~chang/pub/cs201/xwindows -lcs201x -lX11 -lm
umbc9%

umbc9% mv bin cc201
umbc9% mkdir bin

umbc9% ls
bin       cc201     hello.c   oops.txt
umbc9%

umbc9% cat bin
Input error: Is a directory (bin)
umbc9%

umbc9% mv cc201 bin
umbc9% ls bin
cc201
umbc9%

umbc9% ls
bin       hello.c   oops.txt
umbc9% cc201 hello.c
ld:
The shared object /usr/lib/libm.so did not resolve any symbols.
        You may want to remove it from your link line.
umbc9%

umbc9% ls
a.out     bin       hello.c   oops.txt
umbc9%

umbc9% a.out
Hello World
umbc9%