Thread: How to create a library

Hi there,
I'm a newbie in C and I made some functions, but now I wanna use them as libraries.
I create a function corr() in a file corr.c and corr.h and compile that with:
gcc -c corr.c -o corr.o. Now everytime I need to use my function on a program I have to write include the line #include <corr.h> and then type

gcc corr.o myprog.c -o myprog

I want to know if there is any way that I needed to include the line #include <corr.h> in my program and I only had to type:

gcc myprog.c -o myprog

in order to compile?
I apreciate if anyone could send me a link where I can find the info I need or if anyone can explain how do I do that.

Thanks for any help!
Fernando

even when you have the library with you you can not do
gcc myprog.c -o myprog

to generate myprog binary you will have to link it with your library.


gcc -o myprog -L/usr/lib/yourlibrary -I/yourincludepath myprog.c



cheers
Rohit

I have the same question.
How do I made my own library, so I could use it like:

#include <stdio.h>
#include <mylib.h>

without specifying the library path (you don't have to specify
the path for 'stdio.h', do you)?

This is the syntax for IRIX 6.5. It should be similair for your version of linux.

To compile a library:
cc -shared corr.c -o libcorr.so

This will create a shared object. you will need to place the file in a directory specified in your LD_LIBRARY_PATH environment variable.

To compile the executable:
cc myprog.c -lcorr -o myprog

The option -lxxx links in objects from the libxxx.so or libxxx.a (in that order) from directories in the LD_LIBRARY_PATH

This is just like when you use math.h, you have to include the -lm option when you compile.