redhat man page for cap_dup

CAP_INIT(3)						     Linux Programmer's Manual						       CAP_INIT(3)

NAME
       cap_init, cap_free, cap_dup - capability data object storage management

SYNOPSIS
       #include <sys/capability.h>

       cap_t cap_init(void);

       int cap_free(void *obj_d);

       cap_t cap_dup(cap_t cap_p);

USAGE
       cc ... -lcap

DESCRIPTION
       The capabilities associated with a file or process are never edited directly.  Instead, working storage is allocated to contain a represen-
       tation of the capability state.	Capabilities are edited and manipulated only within this working storage area.	Once editing of the  capa-
       bility state is complete, the updated capability state is used to replace the capability state associated with the file or process.

       cap_init  creates  a  capability state in working storage and return a pointer to the capability state.	The initial value of all flags are
       cleared.  The caller should free any releasable memory, when the capability state in working storage is	no  longer  required,  by  calling
       cap_free with the cap_t as an argument.

       cap_free liberates any releasable memory that has been allocated to the capability state identified by obj_d.  The obj_d argument may iden-
       tify either a cap_t entity, or a char * entity allocated by the cap_to_text function.

       cap_dup returns a duplicate capability state in working storage given by the source object cap_p,  allocating  any  memory  necessary,  and
       returning  a  pointer to the newly created capability state.  Once duplicated, no operation on either capability state affects the other in
       any way.

RETURN VALUE
       cap_init and cap_dup return a non-NULL value on success, and NULL on failure.

       cap_free returns zero on success, and -1 on failure.

       On failure, errno(3) is set to EINVAL, or ENOMEM.

CONFORMING TO
       These functions are specified by POSIX.1e.

SEE ALSO
       cap_clear(3), cap_copy_ext(3), cap_from_text(3), cap_get_file(3), cap_get_proc(3)

								   26th May 1997						       CAP_INIT(3)