desperate C programing question (in Off-topic)

so I have 3 files which I intend to link with a make file.

do I need to include #include for the libraries for the c files that don't contain main?

I also have header files for the two .c files which don't contain main. Do I need to #include the "nameoffile.h" on the top of the .c files?

I.E. I have 3 .c files A B and C. B and C contain header files. A contains main. B calls a function from C. I'm getting an error "undefined reference to function" how do I define it?

I've been debugging for a while and trying to understand but can't seem to figure it out.

You need a header file to forward-declare any function you intend to call within that specific file (or, to be more correct, within that "Compilation Unit").

So if I'm calling a function in C while I'm in a function in B, I need to #include the C header file in A,B and C?

you need to include it in B and C

pastebin'ing some source code might make it easier to help you out

thanks! I found the problem, I didn't include the header files in the make file.

But for some reason it has been working before? Do you know why?

you got lucky

wonderful, it no longer works.
Ok here's what I got.
I have 5 files. rsvp.c, courses.c, courses.h, vector.c, vector.h
rsvp.c calls a function from courses.c and then courses.c calls a function in vector.c
in terms of #include
rsvp.c: #includes "courses.h"
courses.c: #includes "vector.h"
and my makefile goes as follows
rsvp.out: rsvp.o course.o vector.o gcc -Wall 0g rsvp.o -o rsvp.out rsvp.o: rsvp.c courses.h gcc -Wall -g -c rsvp.c course.o: courses.c courses.h vector.h gcc -Wall -g -c courses.c vector.o: vector.c vector.h gcc -Wall -c vector.c
I've asked every programming literate person in my dorm and everyone is stumped. Please help!

wonderful, it no longer works.

Ok here's what I got.

I have 5 files. rsvp.c, courses.c, courses.h, vector.c, vector.h

rsvp.c calls a function from courses.c and then courses.c calls a function in vector.c

in terms of #include

rsvp.c: #includes "courses.h"

courses.c: #includes "vector.h"

and my makefile goes as follows

rsvp.out: rsvp.o course.o vector.o
gcc -Wall 0g rsvp.o -o rsvp.out
rsvp.o: rsvp.c courses.h
gcc -Wall -g -c rsvp.c
course.o: courses.c courses.h vector.h
gcc -Wall -g -c courses.c
vector.o: vector.c vector.h
gcc -Wall -c vector.c


I've asked every programming literate person in my dorm and everyone is stumped. Please help!

"gcc -Wall 0g rsvp.o -o rsvp.out"

-g?

Looks like Daz has it!

gcc -Wall 0g rsvp.o -o rsvp.out

should be

gcc -Wall -g courses.o vector.o rsvp.o -o rsvp.out

"rsvp.c calls a function from courses.c and then courses.c calls a function in vector.c"

Are the functions declared in the header and implemented in the source file?

you got it Nightstrike :D. Thanks! I knew the CB community could help.

A little token of gratitude

three4thsforsaken (Single Minion) 128.120.173.122 AdminNightStrike (The Iconics 3e) $500000 12:34 PM EDT