cap_set_flag(3)

1CAP_CLEAR(3)               Linux Programmer's Manual              CAP_CLEAR(3)
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NAME

6       cap_clear,  cap_clear_flag,  cap_get_flag,  cap_set_flag, cap_compare -
7       capability data object manipulation
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SYNOPSIS

10       #include <sys/capability.h>
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12       int cap_clear(cap_t cap_p);
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14       int cap_clear_flag(cap_t cap_p, cap_flag_t flag);
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16       int cap_get_flag(cap_t cap_p, cap_value_t cap,
17                        cap_flag_t flag, cap_flag_value_t *value_p);
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19       int cap_set_flag(cap_t cap_p, cap_flag_t flag, int ncap,
20                        const cap_value_t *caps, cap_flag_value_t value);
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22       int cap_compare(cap_t cap_a, cap_t cap_b);
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24       Link with -lcap.
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DESCRIPTION

27       These functions work on a capability state held in working storage.   A
28       cap_t  holds  information  about  the capabilities in each of the three
29       sets, Permitted, Inheritable, and Effective.  Each capability in a  set
30       may be clear (disabled, 0) or set (enabled, 1).
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32       These functions work with the following data types:
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34       cap_value_t       identifies a capability, such as CAP_CHOWN.
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36       cap_flag_t        identifies  one  of the three flags associated with a
37                         capability (i.e., it  identifies  one  of  the  three
38                         capability  sets).   Valid  values  for this type are
39                         CAP_EFFECTIVE, CAP_INHERITABLE or CAP_PERMITTED.
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41       cap_flag_value_t  identifies the setting  of  a  particular  capability
42                         flag  (i.e,  the  value  of  a  capability in a set).
43                         Valid values for  this  type  are  CAP_CLEAR  [22m(0)  or
44                         CAP_SET (1).
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46       cap_clear() initializes the capability state in working storage identi‐
47       fied by cap_p so that all capability flags are cleared.
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49       cap_clear_flag() clears all of the capabilities of the specified  capa‐
50       bility flag, flag.
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52       cap_get_flag()  obtains the current value of the capability flag, flag,
53       of the capability, cap, from the capability state identified  by  cap_p
54       and places it in the location pointed to by value_p.
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56       cap_set_flag()  sets  the  flag,  flag, of each capability in the array
57       caps in the capability state identified by cap_p to value.   The  argu‐
58       ment, ncap, is used to specify the number of capabilities in the array,
59       caps.
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61       cap_compare() compares two full capability sets and, in the  spirit  of
62       memcmp(), returns zero if the two capability sets are identical. A pos‐
63       itive return value, status, indicates there  is  a  difference  between
64       them.  The  returned  value  carries further information about which of
65       three sets, cap_flag_t flag, differ. Specifically, the  macro  CAP_DIF‐
66       FERS  (status,  flag) evaluates to non-zero if the returned status dif‐
67       fers in its flag components.
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RETURN VALUE

70       cap_clear(),  cap_clear_flag(),   cap_get_flag()   cap_set_flag()   and
71       cap_compare()  return  zero on success, and -1 on failure. Other return
72       values for cap_compare() are described above.
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74       On failure, errno is set to EINVAL, indicating that one  of  the  argu‐
75       ments is invalid.
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CONFORMING TO

78       These  functions are as per the withdrawn POSIX.1e draft specification.
79       cap_clear_flag() and cap_compare() are Linux extensions.
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NAME

SYNOPSIS

DESCRIPTION

RETURN VALUE

CONFORMING TO

SEE ALSO