euidaccess, eaccess - check effective user's permissions for a file
#define _GNU_SOURCE /* See feature_test_macros(7) */
int euidaccess(const char *pathname, int mode);
int eaccess(const char *pathname, int mode);
() checks permissions and existence of
the file identified by its argument pathname
. However, whereas
(2) performs checks using the real user and group identifiers of
the process, euidaccess
() uses the effective identifiers.
is a mask consisting of one or more of R_OK
, and F_OK
, with the same meanings as for access
() 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 returned, and errno
is set appropriately.
As for access
() function was added to glibc in version 2.4.
For an explanation of the terms used in this section, see attributes
|euidaccess (), eaccess ()
These functions are nonstandard. Some other systems have an eaccess
: Using this function to check a process'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