Top manpage + comment in code

commands/simple/top.c

@@ -1,4 +1,6 @@
 
+/* Author: Ben Gras <beng@few.vu.nl>  17 march 2006 */
+
 #define _MINIX 1
 #define _POSIX_SOURCE 1
 

man/man1/top.1

@@ -0,0 +1,60 @@
+.TH TOP 1
+.SH NAME
+top \- show processes sorted by cpu usage
+.SH SYNOPSIS
+.B top
+.SH DESCRIPTION
+Top displays a list of all running processes, once every update interval
+(currently 5 seconds). It is sorted by the cpu usage of the processes in
+the last interval. The first display is the cpu usage of processes since
+the boot time.
+
+At the top of the screen, top shows the current system load averages in
+the last 1-minute, 5-minute and 15-minute intervals. Then, over the
+last top interval it displays: the number of alive, active, and sleeping
+processes; memory free; and cpu usage.
+
+Then it displays all the alive processes sorted by cpu usage in the last
+interval, with a number of fields for every process. Currently the
+following fields are displayed:
+.PP
+  PID
+    The process id of the process. Some processes (so-called kernel
+    tasks) don't have a real process id, as they are not processes
+    that are managed by the process manager, and aren't visible to
+    other user processes by pid. They are shown by having their process
+    slot number in square brackets.
+  USERNAME
+    The username of the effective uid at which the process runs,
+    or a number if the username could not be looked up.
+  PRI
+    The system scheduling priority the process is currently running as.
+    A lower priority number gives a higher scheduling priority. The
+    lowest is 0. The scale is internal to the kernel.
+  NICE
+    The base scheduling priority the process has been given at startup.
+    0 is normal for a regular user process; the range is -20 to 20
+    (PRIO_MIN and PRIO_MAX in <sys/resource.h>. Most system processes
+    are given higher base priorities.
+  SIZE
+    Text + data size in kilobytes.
+  STATE
+    RUN if the process is runnable, empty if blocking. 
+  TIME
+    Total number of cpu time spent in the process itself. So-called
+    system time (cpu time spent on behalf of this process by another
+    process, generally a system process) is not seen here.
+  CPU
+    Percentage of time that the process was running in the last interval.
+  COMMAND
+    Name of the command that belongs to this process.
+
+.SH "SEE ALSO"
+.BR ps (1)
+.SH BUGS
+This is a from-scratch reimplementation of top for MINIX 3.
+Many features (such as interactive commands) are not implemented.
+Sorting is only done by cpu usage currently. Displayed state is
+only RUN or empty.
+.SH AUTHOR
+Ben Gras (beng@few.vu.nl)