Section (3) euidaccess
euidaccess, eaccess — check effective user_zsingle_quotesz_s permissions for a file
#define _GNU_SOURCE /* See feature_test_macros(7) */ #include <unistd.h>
||const char *pathname,|
||const char *pathname,|
euidaccess() checks permissions and
existence of the file identified by its argument
pathname. However, whereas
access(2) performs checks
using the real user and group identifiers of the process,
euidaccess() uses the effective
mode is a mask
consisting of one or more of
F_OK, with the same meanings as for
eaccess() is a synonym for
euidaccess(), provided for
compatibility with some other systems.
On success (all requested permissions granted), zero is
returned. On error (at least one bit in
mode asked for a permission
that is denied, or some other error occurred), −1 is
errno is set
As for access(2).
For an explanation of the terms used in this section, see attributes(7).
Using this function to check a process_zsingle_quotesz_s permissions on a file before performing some operation based on that information leads to race conditions: the file permissions may change between the two steps. Generally, it is safer just to attempt the desired operation and handle any permission error that occurs.
This function always dereferences symbolic links. If you
need to check the permissions on a symbolic link, use
faccessat(2) with the flags
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