[src/trunk]: src/usr.bin/renice Rearrange the description of the renice argum...

[dholland <dholland%NetBSD.org@localhost>]

details:   https://anonhg.NetBSD.org/src/rev/951e2201fb28
branches:  trunk
changeset: 956139:951e2201fb28
user:      dholland <dholland%NetBSD.org@localhost>
date:      Thu Oct 22 19:55:14 2020 +0000

description:
Rearrange the description of the renice arguments and options.

Don't refer to "who" parameters that aren't defined anywhere, make it
clear how the options are actually interpreted (since it's not and
can't be getopt-style), and also document the behavior when a named
collection of processes doesn't start out with uniform priority.

The dangling "who" parameters issue seems to date back to 4.4.

Prompted by Ottavio Caruso.

diffstat:

 usr.bin/renice/renice.8 |  112 +++++++++++++++++++++++++----------------------
 1 files changed, 59 insertions(+), 53 deletions(-)

diffs (166 lines):

diff -r 18a9dd2fca0a -r 951e2201fb28 usr.bin/renice/renice.8
--- a/usr.bin/renice/renice.8   Thu Oct 22 19:39:48 2020 +0000
+++ b/usr.bin/renice/renice.8   Thu Oct 22 19:55:14 2020 +0000
@@ -1,4 +1,4 @@
-.\"    $NetBSD: renice.8,v 1.15 2012/12/06 07:52:12 wiz Exp $
+.\"    $NetBSD: renice.8,v 1.16 2020/10/22 19:55:14 dholland Exp $
 .\"
 .\" Copyright (c) 1983, 1991, 1993
 .\"    The Regents of the University of California.  All rights reserved.
@@ -29,7 +29,7 @@
 .\"
 .\"     from: @(#)renice.8     8.1 (Berkeley) 6/9/93
 .\"
-.Dd December 6, 2012
+.Dd October 22, 2020
 .Dt RENICE 8
 .Os
 .Sh NAME
@@ -39,77 +39,76 @@
 .Nm
 .Ar priority
 .Oo
-.Op Fl p
-.Ar pid ...
+.Op Fl pgu
+.Ar who ...
 .Oc
-.Oo
-.Fl g
-.Ar pgrp ...
-.Oc
-.Oo
-.Fl u
-.Ar user ...
-.Oc
+.Ar ...
 .Nm
 .Fl n
 .Ar increment
 .Oo
-.Op Fl p
-.Ar pid ...
+.Op Fl pgu
+.Ar who ...
 .Oc
-.Oo
-.Fl g
-.Ar pgrp ...
-.Oc
-.Oo
-.Fl u
-.Ar user ...
-.Oc
+.Ar ...
 .Sh DESCRIPTION
 .Nm
 alters the
 scheduling priority of one or more running processes.
+The first argument is the new priority to apply, or if
+.Fl n
+is given, the change to make (applied additively) to the priority.
+This argument may be negative.
+(The interpretation of priorities is discussed below.)
+.Pp
 The following
 .Ar who
-parameters are interpreted as process ID's, process group
-ID's, or user names.
-.Nm Ns 'ing
-a process group causes all processes in the process group
-to have their scheduling priority altered.
-.Nm Ns 'ing
-a user causes all processes owned by the user to have
-their scheduling priority altered.
-By default, the processes to be affected are specified by
-their process ID's.
-.Pp
-Options supported by
-.Nm :
+parameters name the target processes, as either process IDs, process
+group IDs, or user names.
+The
+.It pgf
+options control the interpretation as follows:
 .Bl -tag -width Ds
 .It Fl g
-Force
+Interpret
 .Ar who
-parameters to be interpreted as process group ID's.
-.It Fl n
-Instead of changing the specified processes to the given priority,
-interpret the following argument as an increment to be applied to
-the current priority of each process.
+parameters as process group ID's.
 .It Fl u
-Force the
+Interpret
 .Ar who
-parameters to be interpreted as user names.
+parameters as user names.
 .It Fl p
-Resets the
+Interpret
 .Ar who
-interpretation to be (the default) process ID's.
+parameters as process IDs.
+This is the default.
 .El
 .Pp
-For example,
-.Bd -literal -offset indent
-renice +1 987 -u daemon root -p 32
-.Ed
-.Pp
-would change the priority of process ID's 987 and 32, and
-all processes owned by users daemon and root.
+Each
+.Ar who
+parameter is processed separately and updates the priority of the
+processes it names as follows:
+.Bl -tag -width "with Ds"
+.It with Fl g
+All processes in the process group are updated to the selected
+priority.
+If an
+.Ar increment
+is used, the increment is added to the highest priority found among
+the members of the process group prior to the change.
+.It with Fl u
+All processes belonging to the specified user are updated to the
+selected priority.
+If an
+.Ar increment
+is used, the increment is added to the highest priority found among
+the processes belonging to the user prior to the change.
+.It with Fl p
+The named process is updated to the selected priority.
+If an
+.Ar increment
+is used, the increment is added to the process's previous priority.
+.El
 .Pp
 Users other than the super-user may only alter the priority of
 processes they own,
@@ -136,6 +135,13 @@
 .It Pa /etc/passwd
 to map user names to user ID's
 .El
+.Sh EXAMPLES
+.Bd -literal -offset indent
+renice +1 987 -u daemon root -p 32
+.Ed
+.Pp
+changes the priority of process ID's 987 and 32, and
+all processes owned by users daemon and root.
 .Sh SEE ALSO
 .Xr nice 1 ,
 .Xr prenice 1 ,
@@ -147,5 +153,5 @@
 command appeared in
 .Bx 4.0 .
 .Sh BUGS
-Non super-users can not increase scheduling priorities of their own processes,
+Non-super-users can not increase scheduling priorities of their own processes,
 even if they were the ones that decreased the priorities in the first place.