Simple makefile question
 

I'm new to makefile questions so be gentle:

I have a hello world cpp app.

In the command line if I type:
g++ -o program main.cpp
then I get an exe called 'program' which executes fine.

But I want to use a makefile because I need to learn it for another larger project. My make file is as follows:
--------------------------------------
program: main.o
g++ -o program main.o
main.o: main.cpp
g++ -o main.cpp
--------------------------------------

Now when I type 'make program' the output I get is:
g++ -o main.cpp
g++: no input files
make: *** [main.o] Error 1

What is wrong with this simple makefile of mine?

I am using Fedora.

Thanks

Harry

Makefile format
 

Hi Harry,

The format inside your Makefile is incorrect. Do a search in google to find the format. Here's an example.

# The general syntax of a Makefile Target Rule is

target [target...] : [dependent ....]
[ command ...]

So for you:

program: program.o
gcc -o program program.o something.o
program.o: program.c
gcc -c program.c


... etc.

Hope that helps.
Dennis.

Thanks
 

Hi,
Thaanks for your quick reply.

I noticed that on the last line of my make file the
g++ -o main.cpp
should have been
g++ -c main.cpp

I changed it and it now works. I will try your method also. Is my method the wrong way to do it moving forward?

Harry

Makefiles
 

Hi HarryBoy,

Whatever works for you is what I recommend. :)

If you would like examples then quite complex examples exist in anyone of the GNU packages.

But I would recommend keeping it simple.