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access(2)                        System Calls                        access(2)



NAME
       access - determine accessibility of a file

SYNOPSIS
       #include <unistd.h>

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

DESCRIPTION
       The  access() function checks the file named by the pathname pointed to
       by the path argument for accessibility according  to  the  bit  pattern
       contained  in  amode,  using the real user ID in place of the effective
       user ID and the real group ID in place of the effective group ID.  This
       allows  a  setuid process to verify that the user running it would have
       had permission to access this file.

       The value of amode is either the bitwise inclusive  OR  of  the  access
       permissions  to  be  checked  (R_OK, W_OK, X_OK) or the existence test,
       F_OK.

       These constants are defined in <&lt;unistd.h>&gt; as follows:

       R_OK     Test for read permission.



       W_OK     Test for write permission.



       X_OK     Test for execute or search permission.



       F_OK     Check existence of file



       See intro(2) for additional information about "File Access Permission".

       If any access permissions are to be checked, each will be checked indi-
       vidually,  as  described  in  intro(2).  If the process has appropriate
       privileges, an implementation may indicate success  for  X_OK  even  if
       none of the execute file permission bits are set.

RETURN VALUES
       If  the requested access is permitted, access() succeeds and returns 0.
       Otherwise, -1 is returned and errno is set to indicate the error.

ERRORS
       The access() function will fail if:

       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.



       EFAULT                  path points to an illegal address.



       EINTR                   A signal was caught during the  access()  func-
                               tion.



       ELOOP                   Too  many  symbolic  links  were encountered in
                               resolving path.



       ELOOP                   A loop exists  in  symbolic  links  encountered
                               during resolution of the path argument.



       ENAMETOOLONG            The   length   of  the  path  argument  exceeds
                               {PATH_MAX}, or a pathname component  is  longer
                               than  {NAME_MAX}  while  _POSIX_NO_TRUNC  is in
                               effect.



       ENOENT                  A component of path does not name  an  existing
                               file or path is an empty string.



       ENOLINK                 path points to a remote machine and the link to
                               that machine is no longer active.



       ENOTDIR                 A component of the path prefix is not a  direc-
                               tory.



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



       The access() function may fail if:

       EINVAL                  The value of the amode argument is invalid.



       ENAMETOOLONG            Pathname resolution of a symbolic link produced
                               an  intermediate  result  whose  length exceeds
                               {PATH_MAX}.



       ETXTBSY                 Write access is requested for a pure  procedure
                               (shared text) file that is being executed.



USAGE
       Additional  values  of amode other than the set defined in the descrip-
       tion might be valid, for example, if a system has extended access  con-
       trols.

ATTRIBUTES
       See attributes(5) for descriptions of the following attributes:


       tab()     allbox;     cw(2.750000i)|    cw(2.750000i)    lw(2.750000i)|
       lw(2.750000i).  ATTRIBUTE TYPEATTRIBUTE VALUE Interface  StabilityStan-
       dard MT-LevelAsync-Signal-Safe


SEE ALSO
       intro(2), chmod(2), stat(2), attributes(5), standards(5)



SunOS 5.10                        23 Apr 2002                        access(2)