plan9 man page for access

ACCESS(2)							System Calls Manual							 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 directories leading to the file must permit searches.
       Zero is returned if the desired access is permitted, -1 if not.

       Only  access  bits  are	checked.   A  directory  may  be  announced as writable by access, but an attempt to open it for writing will fail
       (although files may be created there); a file may look executable, but exec(2) will fail unless it is in proper format.

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

SEE ALSO
       stat(2)

DIAGNOSTICS
       Sets errstr.

																	 ACCESS(2)