.if t .if !\nv .tl '--''--' .ps20 .sp 4.25i .ft B .ce UNIX PROGRAMMER'S MANUAL .ps10 .sp |5i .ft I .ce Seventh Edition, Volume 1 .ce Berkeley PDP\-11 Version .sp |5.75i .ce April, 1983 .sp |9.2i .ft R .ce Computer Science Division .ce Department of Electrical Engineering and Computer Science .ce University of California .ce Berkeley, California 94720 .bp