ACCESS(2)                                               ACCESS(2)

     NAME
          access - determine accessibility of file

     SYNOPSIS
          #include <u.h>
          #include <libc.h>

          int access(char *name, int mode)

     DESCRIPTION
          Access evaluates the given file name for accessibility.  If
          mode&4 is nonzero, read permission is expected; if mode&2,
          write permission; if mode&1, execute permission.  If
          mode==0, the file merely need exist.  In any case all direc-
          tories leading to the file must permit searches.  Zero is
          returned if the desired access is permitted, -1 if not.

          Only access for open is checked.  A file may look exe-
          cutable, but exec(2) will fail unless it is in proper for-
          mat.

          The include file defines AEXIST=0, AEXEC=1, AWRITE=2, and
          AREAD=4.

     SOURCE
          /sys/src/libc/9sys/access.c

     SEE ALSO
          stat(2)

     DIAGNOSTICS
          Sets errstr.

     BUGS
          Since file permissions are checked by the server and group
          information is not known to the client, access must open the
          file to check permissions.  (It calls stat(2) to check sim-
          ple existence.)