проверить действующие права пользователя для файла (check effective user's permissions for a file)
Имя (Name)
euidaccess, eaccess - check effective user's permissions for a
file
Синопсис (Synopsis)
#define _GNU_SOURCE /* See feature_test_macros(7) */
#include <unistd.h>
int euidaccess(const char *pathname, int mode);
int eaccess(const char *pathname, int mode);
Описание (Description)
Like access(2), 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
identifiers.
mode is a mask consisting of one or more of R_OK, W_OK, X_OK, and
F_OK, with the same meanings as for access(2).
eaccess() is a synonym for euidaccess(), provided for
compatibility with some other systems.
Возвращаемое значение (Return value)
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 to indicate the error.
Ошибки (Error)
As for access(2).
Версии (Versions)
The eaccess() function was added to glibc in version 2.4.
Атрибуты (Attributes)
For an explanation of the terms used in this section, see
attributes(7).
┌──────────────────────────────────────┬───────────────┬─────────┐
│Interface │ Attribute │ Value │
├──────────────────────────────────────┼───────────────┼─────────┤
│euidaccess(), eaccess() │ Thread safety │ MT-Safe │
└──────────────────────────────────────┴───────────────┴─────────┘
Стандарты (Conforming to)
These functions are nonstandard. Some other systems have an
eaccess() function.
Примечание (Note)
Warning: 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 AT_EACCESS and AT_SYMLINK_NOFOLLOW.
Смотри также (See also)
access(2), chmod(2), chown(2), faccessat(2), open(2), setgid(2),
setuid(2), stat(2), credentials(7), path_resolution(7)
