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25 .TH FACCESSAT 2 2012-05-04 "Linux" "Linux Programmer's Manual"
27 faccessat \- check user's permissions of a file relative to a \
28 directory file descriptor
31 .B #include <fcntl.h> /* Definition of AT_* constants */
32 .B #include <unistd.h>
34 .BI "int faccessat(int " dirfd ", const char *" pathname ", int " \
35 mode ", int " flags );
39 Feature Test Macro Requirements for glibc (see
40 .BR feature_test_macros (7)):
49 _XOPEN_SOURCE\ >=\ 700 || _POSIX_C_SOURCE\ >=\ 200809L
59 system call operates in exactly the same way as
61 except for the differences described in this manual page.
63 If the pathname given in
65 is relative, then it is interpreted relative to the directory
66 referred to by the file descriptor
68 (rather than relative to the current working directory of
69 the calling process, as is done by
71 for a relative pathname).
81 is interpreted relative to the current working
82 directory of the calling process (like
92 is constructed by ORing together zero or more of the following values:
95 Perform access checks using the effective user and group IDs.
98 uses the real IDs (like
101 .B AT_SYMLINK_NOFOLLOW
104 is a symbolic link, do not dereference it:
105 instead return information about the link itself.
107 On success, (all requested permissions granted)
110 On error, \-1 is returned and
112 is set to indicate the error.
114 The same errors that occur for
118 The following additional errors can occur for
123 is not a valid file descriptor.
126 Invalid flag specified in
133 is a file descriptor referring to a file other than a directory.
136 was added to Linux in kernel 2.6.16;
137 library support was added to glibc in version 2.4.
143 for an explanation of the need for
148 is subject to the same kinds of races as
156 .B AT_SYMLINK_NOFOLLOW
157 flags are actually implemented within the glibc wrapper function for
159 If either of these flags are specified, then the wrapper function employs
161 to determine access permissions.
167 .BR path_resolution (7),