add dirread(2) to read(2)
 [rsc] --rw-rw-r-- M 1185876 glenda sys 1899 Jan 24 09:41 sys/man/2/read
	/n/sourcesdump/2006/0124/plan9/sys/man/2/read:86,93 - 
	/n/sourcesdump/2006/0125/plan9/sys/man/2/read:86,94
	  .B /sys/src/libc/port/readn.c
	  .SH SEE ALSO
	  .IR intro (2),
	- .IR open (2), 
	+ .IR dirread (2),
	  .IR dup (2),
	+ .IR open (2),
	  .IR pipe (2),
	  .IR readv (2)
	  .SH DIAGNOSTICS