How to make a C library

Suposse you want to create a library called ‘libhello’ that provides an ‘hello’ function to include in your program ‘main.c’.

Start by writing ‘hello.c’, e.g.:

void hello ();

main (int argc, char *argv[])
hello ();

And the ‘main.c’,e.g.:


hello ()
printf ("Hello!n");

Compile ‘hello.c’ into an object with the ‘-c’ option to ‘gcc’:

$ gcc -c hello.c

Create the library using ar(1) e ranlib(1):

$ ar cru libhello.a hello.o
$ ranlib libhello.a

And finally compile your program using the new library you’ve created:

$ gcc -o hello main.c libhello.a
$ ./hello

* [[|The Goat Book]] – Freely available book describing how to use GNU Autoconf, Automake, and Libtool.
* The ar(1) e ranlib(1) manpages.