ubuntu and libcap (capabilities) undefined reference

Question

I'm trying to compile the following minimal C code on ubuntu 10.10:

#include <sys/capability.h>

void main(void)
{
        cap_t cap;
        cap = cap_get_proc();
}

with gcc -lcap test.c which gives me the following error:

/tmp/ccCQFyXS.o: In function `main':
test.c:(.text+0x9): undefined reference to `cap_get_proc'
collect2: ld a retourné 1 code d'état d'exécution

I have libcap2-dev and libcap2-bin installed, version 2.21

ls /lib/libcap.*
/lib/libcap.a  /lib/libcap.so  /lib/libcap.so.2  /lib/libcap.so.2.21

The same code with same gcc command build successfully on arch and gentoo

What should I do to get it build on ubuntu too?

Answer 1

Try gcc -Wl,--no-as-needed -lcap test.c or gcc test.c -lcap.
Hope this helps!

Answer 2

I'm working on Ubuntu 10.04 and I had the same problem (sys/capability.h not present on the file system).

I resolved this problem installing via Synaptic Package Manager the package libcap-dev (version 1:2.17-2ubuntul) which populates the /usr/include/sys folder with the capability.h file.

Answer 3

For RHEL:

yum install libcap-devel
gcc -lcap test.c