top: document an existing provision of pid monitoring

Since its inception top has provided for monitoring
only specific process ids via the -p command line
switch.  This provision has also embraced the top
process itself, even though its pid wasn't yet known.

This commit simply documents the special zero value,
which would otherwise be an invalid process id.

Signed-off-by: Jim Warner <james.warner@comcast.net>

diff --git a/top/top.1 b/top/top.1
index ab8f4a982c71516db2dc77184742d6845578a701..cd11575191bf0668627d42f012ca305b3bfabc03 100644 (file)
--- a/top/top.1
+++ b/top/top.1
@@ -302,6 +302,9 @@ This option can be given up to \*(WP times, or you can provide a comma delimited
 list with up to \*(WP pids.
 Co-mingling both approaches is permitted.
 
+A pid value of zero will be treated as the process id of the \*(We program
+itself once it is running.
+
 This is a \*(CO only and should you wish to return to normal operation,
 it is not necessary to quit and and restart \*(We \*(Em just issue any
 of these \*(CIs: '=', 'u' or 'U'.