euidaccess(3) — Linux manual page


euidaccess(3)           Library Functions Manual           euidaccess(3)

NAME         top

       euidaccess, eaccess - check effective user's permissions for a

LIBRARY         top

       Standard C library (libc, -lc)

SYNOPSIS         top

       #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);

DESCRIPTION         top

       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

       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.

RETURN VALUE         top

       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.

ERRORS         top

       As for access(2).

ATTRIBUTES         top

       For an explanation of the terms used in this section, see
       │ Interface                           Attribute     Value   │
       │ euidaccess(), eaccess()             │ Thread safety │ MT-Safe │

VERSIONS         top

       Some other systems have an eaccess() function.

STANDARDS         top


HISTORY         top

              glibc 2.4.

NOTES         top

       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.

SEE ALSO         top

       access(2), chmod(2), chown(2), faccessat(2), open(2), setgid(2),
       setuid(2), stat(2), credentials(7), path_resolution(7)

COLOPHON         top

       This page is part of the man-pages (Linux kernel and C library
       user-space interface documentation) project.  Information about
       the project can be found at 
       ⟨⟩.  If you have a bug report
       for this manual page, see
       This page was obtained from the tarball man-pages-6.9.1.tar.gz
       fetched from
       ⟨⟩ on
       2024-06-26.  If you discover any rendering problems in this HTML
       version of the page, or you believe there is a better or more up-
       to-date source for the page, or you have corrections or
       improvements to the information in this COLOPHON (which is not
       part of the original manual page), send a mail to

Linux man-pages 6.9.1          2024-05-02                  euidaccess(3)

Pages that refer to this page: access(2)credentials(7)