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


   #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);


   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.


   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


   As for access(2).


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


   For   an   explanation   of   the  terms  used  in  this  section,  see

   Interface                Attribute      Value   
   euidaccess(), eaccess()  Thread safety  MT-Safe 


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


   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


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


   This page is part of release 4.09 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

                              2015-03-02                     EUIDACCESS(3)


Personal Opportunity - Free software gives you access to billions of dollars of software at no cost. Use this software for your business, personal use or to develop a profitable skill. Access to source code provides access to a level of capabilities/information that companies protect though copyrights. Open source is a core component of the Internet and it is available to you. Leverage the billions of dollars in resources and capabilities to build a career, establish a business or change the world. The potential is endless for those who understand the opportunity.

Business Opportunity - Goldman Sachs, IBM and countless large corporations are leveraging open source to reduce costs, develop products and increase their bottom lines. Learn what these companies know about open source and how open source can give you the advantage.

Free Software

Free Software provides computer programs and capabilities at no cost but more importantly, it provides the freedom to run, edit, contribute to, and share the software. The importance of free software is a matter of access, not price. Software at no cost is a benefit but ownership rights to the software and source code is far more significant.

Free Office Software - The Libre Office suite provides top desktop productivity tools for free. This includes, a word processor, spreadsheet, presentation engine, drawing and flowcharting, database and math applications. Libre Office is available for Linux or Windows.

Free Books

The Free Books Library is a collection of thousands of the most popular public domain books in an online readable format. The collection includes great classical literature and more recent works where the U.S. copyright has expired. These books are yours to read and use without restrictions.

Source Code - Want to change a program or know how it works? Open Source provides the source code for its programs so that anyone can use, modify or learn how to write those programs themselves. Visit the GNU source code repositories to download the source.


Study at Harvard, Stanford or MIT - Open edX provides free online courses from Harvard, MIT, Columbia, UC Berkeley and other top Universities. Hundreds of courses for almost all major subjects and course levels. Open edx also offers some paid courses and selected certifications.

Linux Manual Pages - A man or manual page is a form of software documentation found on Linux/Unix operating systems. Topics covered include computer programs (including library and system calls), formal standards and conventions, and even abstract concepts.