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access(2)							    access(2)



NAME

  access - Determines the accessibility	of a file

SYNOPSIS

  #include <&lt;unistd.h>&gt;

  int access (
	  const	char *path,
	  int access_mode) ;

STANDARDS

  Interfaces documented	on this	reference page conform to industry standards
  as follows:

  access():  XPG4, XPG4-UNIX

  Refer	to the standards(5) reference page for more information	about indus-
  try standards	and associated tags.

PARAMETERS

  path
      Points to	the file pathname.  When the path parameter refers to a	sym-
      bolic link, the access() function	returns	information about the file
      pointed to by the	symbolic link.

      Permission to access all components of the path parameter	is determined
      by using a real user ID instead of an effective user ID, and a group
      access list (including a real group ID) instead of an effective group
      ID.

  access_mode
      Specifies	the type of access. The	bit pattern contained in the
      access_mode parameter is constructed by a	logical	OR of the following
      values:

      R_OK	Checks read permission.

      W_OK	Checks write permission.

      X_OK	Checks execute (search)	permission.

      F_OK	Checks to see if the file exists.

DESCRIPTION

  The access() function	checks for accessibility of the	file specified by a
  pathname.


  Only access bits are checked.	 A directory may be indicated as writable by
  access(), but	an attempt to open it for writing will fail (although files
  may be created there); a file's access bits may indicate that	it is execut-
  able,	but the	execve() function can fail if the file does not	contain	the
  proper format.

RETURN VALUES

  Upon successful completion, the access() function returns value of 0
  (zero).  Otherwise, a	value of -1 is returned	and errno is set to indicate
  the error.

ERRORS

  If the access() function fails, access to the	file specified by the path
  parameter is denied and errno	may be set to one of the following values:

  [EACCES]  Permission bits of the file	mode do	not permit the requested
	    access, or search permission is denied on a	component of the path
	    prefix.  The owner of a file has permission	checked	with respect
	    to the ``owner'' read, write, and execute mode bits, members of
	    the	file's group other than	the owner have permission checked
	    with respect to the	``group'' mode bits, and all others have per-
	    missions checked with respect to the ``other'' mode	bits.

  [EFAULT]  The	path parameter points outside the process' allocated address
	    space.

  [EINVAL]  The	pathname contains a character with the high-order bit set.

  [EIO]	    An I/O error occurred while	reading	from or	writing	to the file
	    system.

  [ELOOP]   Too	many symbolic links were encountered in	translating the	path-
	    name.

  [ENAMETOOLONG]
	    A component	of a pathname exceeded PATH_MAX	characters, or an
	    entire pathname exceeded NAME_MAX characters.

  [ENOENT]  The	named file does	not exist or is	an empty string.

  [ENOTDIR] A component	of the path prefix is not a directory.

  [EROFS]   Write access is requested for a file on a read-only	file system.

RELATED	INFORMATION

  Functions: chmod(2), stat(2)

  Standards: standards(5)