NAME

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

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);

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.

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
       appropriately.

ERRORS

       As for access(2).

VERSIONS

       The eaccess() function was added to glibc in version 2.4.

ATTRIBUTES

       For an explanation of the terms used in this section, see attributes(7).

       ┌────────────────────────┬───────────────┬─────────┐
       │Interface               │ Attribute     │ Value   │
       ├────────────────────────┼───────────────┼─────────┤
       │euidaccess(), eaccess() │ Thread safety │ MT-Safe │
       └────────────────────────┴───────────────┴─────────┘

CONFORMING TO

       These functions are nonstandard.  Some other systems have an eaccess() function.

NOTES

       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

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

COLOPHON

       This  page  is  part  of  release  5.10  of  the  Linux man-pages project.  A description of the project,
       information  about  reporting  bugs,  and  the  latest  version  of  this   page,   can   be   found   at
       https://www.kernel.org/doc/man-pages/.

                                                   2017-09-15                                      EUIDACCESS(3)