[cs631apue] compile issue

[mseaton]

Hello,
  Compiling each source file separately(using -c option), each file 
including the main one ls.c works fine. Also after compiling all source 
files together one one line also works okay, but if I compile ls.c by 
itself, I get the following:

undefined reference to `SortFileSize'
ls.c:162: undefined reference to `PrintBlocks'
ls.c:164: undefined reference to `LongFormat'
ls.c:166: undefined reference to `PrintInodeNumber'

These functions are all .c files. I originally had include statements 
for each of these files (#include "PrintBlocks.s" for example) inside 
ls.c, but I removed them because I have a created header file that has 
these prototypes defined. Everything worked when I had these include 
files.

Should I put them back in or am I missing something? Also, all the other 
.c files has the header files I created.

Marlon