Can't compile code in linux

[fasoulas]

i have a problem compiling a very simple c++ in linux.

Basically i have written ,compiled and run the program in Microsoft visual studio 2008 and it runs flawlessly but the same code on linux doesn't compile.

I tried with geany , codeblocks and the command line but i get the same error every time

the program is consisted by 3 files the main.cpp math.h and math.cpp
the main.cpp is the file tha includes the main function

i get this when i try to compile main.cpp
main.cpp.text+0xa): undefined reference to `menu()'
main.cpp.text+0x83): undefined reference to `square_of_number(double)'
main.cpp.text+0xfe): undefined reference to `sum_of_numbers(double, double)'
main.cpp.text+0x179): undefined reference to `product_of_numbers(double, double)'

and this when i try to compile math.cpp
start.S:115: undefined reference to `main'

[lisati]

Are you able to show us some code?
If you do, put [code] at the start and [/code] at the end

[Sim & Co.]

g++ main.cpp math.h math.cpp -o main

-- or simply add an include statement in main.cpp.

[fasoulas]

g++ main.cpp math.h math.cpp -o main

-- or simply add an include statement in main.cpp.

if i put this in terminal it doesn't show the error messages,what does this mean? How can i run the program to see if it works?

Sorry if i make a lot of questions but i mainly program on visual studio but i also want to learn on linux

By the way thanks both for replying

[Sim & Co.]

No error messages - possible ( most of the bugs doesn't show off just like that ) success.

./main

** Execute it from the directory you were in when you compiled your application.

[fasoulas]

No error messages - possible ( most of the bugs doesn't show off just like that ) success.

./main

** Execute it from the directory you were in when you compiled your application.

It worked.Thanks a lot

But do you know a way to do this in geany?

[Sim & Co.]

It worked.Thanks a lot

But do you know a way to do this in geany?

Wikipedia know how to

[fasoulas]

Wikipedia know how to

OK i will search and find.

thanks again

[MadCow108]

A header file won't solve the linking problem
undefined reference is an error in the linking stage, not the compile stage.

What the compiler did in Sim's line is following:
gcc -c math.cpp -o math.o //compile math.cpp to object file
gcc -c main.cpp -o main.o //compile main.cpp to object file
gcc main.o math.o -o math // link main.o and math.o to math executable


so far I know geany has no (yet) got a good way to do this without makefiles.
A makefile is a file containing all the build rules executed with the command make
http://www.gnu.org/software/make/manual/make.html

[Sim & Co.]

OK i will search and find.

thanks again

What are you going to search for ? The link points to a specific section and all you need to do is read and understand it