Using math library problem

[amiralis]

Hi all,

I include <math.h> to use functions such as "floor()". and also I use -lm to link to math library like the following:

all: setitimer-helper squish-pty squish-unix

CC = gcc
CFLAGS = -Wall -W
LDFLAGS = -lm
setitimer-helper: setitimer-helper.o
squish-pty: squish-pty.o
squish-unix: squish-unix.o

clean: 
    rm -f *.o setitimer-helper squish-pty squish-unix

But still I receive an error which says: "undefined reference to 'floor'"

What would be the problem?

Thanks in advance,

[weaknessforcats]

An undefined reference is usually referrinf to something that has not been declared.

Have you declared floor() as a function before calling it?

[nextstep]

I think floor() is a function of math.h lib therefore no need to define it

[zmbd]

Weaknessforcats is correct, you are missing a reference to the function in order for this error to occur.

I don't see in your posted code where you have the include for the math.h library, nor do I see a proper sub-reference/compile-time linker to the math library. Also missing is the context for the call to the floor function.

You might take a look at:

http://www.cs.cf.ac.uk/Dave/C/node17.html