libraries

C/C++ libraries for various purposes

There are a variety of C/C++ libraries that can be accessed on the CSIL systems, or installed on your own systems.

One of the tough things to get right when using libraries is to know what magic sauce you need in your Makefile to get the libraries to compile and link correctly.

Typically, the header files (.h) files live in /usr/include and the libraries that you link with live in /usr/lib.

But, sometimes you need special stuff to help the compiler and linker find the files you need.

That’s where the pkg-config utility can help. Here’s an example of setting things up for the cairo library. Notice how the variables CAIRO_CFLAGS and CAIRO_LIBS are initialized and then used.

CC=g++                                                                                              
#Compiler Optionen 

MAIN= cairoDemo

#the cairo header directory
CAIRO_CFLAGS=$(shell pkg-config --cflags cairo)
CAIRO_LIBS=$(shell pkg-config --libs cairo)

CXXFLAGS= -Wall -DEBUG $(CAIRO_CFLAGS)

#actual compiling

all: $(MAIN)

cairoDemo: cairoDemo.o
	$(CC) $(CXXFLAGS) -o $@ $< $(CAIRO_CFLAGS) $(CAIRO_LIBS)

clean:
	/bin/rm -f *.o $(MAIN)

Using libraries on other systems

• On MacOS systems, you can install many of these packages with homebrew.
• On Windows, one option to install many of them is Cygwin