PR_CAPBSET_READ(2const)                                PR_CAPBSET_READ(2const)

NAME
       PR_CAPBSET_READ - read the calling thread's capability bounding set

LIBRARY
       Standard C library (libc, -lc)

SYNOPSIS
       #include <linux/prctl.h>  /* Definition of PR_* constants */
       #include <sys/prctl.h>

       int prctl(PR_CAPBSET_READ, long cap);

DESCRIPTION
       Return 1 if the capability specified in cap is in the calling thread's
       capability bounding set, or 0 if it is not.

       The capability constants are defined in <linux/capability.h>.

       The capability bounding set dictates whether the process can receive
       the capability through a file's permitted capability set on a
       subsequent call to execve(2).

RETURN VALUE
       On success, this call returns the boolean value described above.  On
       error, -1 is returned, and errno is set to indicate the error.

ERRORS
       EINVAL cap does not specify a valid capability.

VERSIONS
       A higher-level interface layered on top of this operation is provided
       in the libcap(3) library in the form of cap_get_bound(3).

STANDARDS
       Linux.

HISTORY
       Linux 2.6.25.

SEE ALSO
       prctl(2), PR_CAPBSET_DROP(2const), libcap(3), cap_get_bound(3)

Linux man-pages 6.18              2026-02-08           PR_CAPBSET_READ(2const)