I wrote an implementation of several functions spread across multiple c files and those functions are declared in single header file along with several structures and preprocessors. I have been trying to compile them as a library and link it to a program. During make, it raises "undefined reference" error against methods. I referred the links (see below) but they were discuss about the usage of single .c & .h. I followed the advice but the errors still persist.
How to compile a static library in Linux?
"Undefined reference " to a function defined in static library
Undefined reference while linking static C library
I tried to compile them as normal using make and it was successful. The makefile which successfully compiled is given below:
INCLUDES = -I/usr/include
ffilter:
gcc -Wextra -Wall -lm home.c filter.c handlerprocess.c handlerpack.c handlersys.c handlerfile.c handlerpcap.c helper.c -o ffilter $(INCLUDES)
clean:
$(RM) *.o *~ ffilter
Makefile code for compiling and linking the same as library with program, which raise errors, is given below. Would anyone help me to solve this problem.
CC = gcc
CFLAGS = -Wextra -Wall
TARGET = ffilter
all: $(TARGET)
#final output, linking library with main program
$(TARGET): home.o libhandlers.a
$(CC) -o $(TARGET) home.o -L. -lhandlers
#main c program
home.o: home.c home.h
$(CC) $(CFLAGS) -c home.c home.h
#implementation of library
filter.o: filter.h filter.c handlerprocess.c handlerpack.c handlersys.c handlerfile.c handlerpcap.c helper.c
$(CC) $(CFLAGS) -c -O -lm filter.h filter.c handlerprocess.c handlerpack.c handlersys.c handlerfile.c handlerpcap.c helper.c
#creating library
libhandlers.a: filter.o
ar rcs libhandlers.a filter.o
#remove built files
clean:
$(RM) *.o *.a *.gch *~ $(TARGET)
