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Command: top | Section: 1 | Source: OpenBSD | File: top.1
TOP(1) FreeBSD General Commands Manual TOP(1)
NAME
top - display and update information about the top CPU processes
SYNOPSIS
top [-1bCHIinqStu] [-d count] [-g string] [-o [-]field] [-p pid]
[-s time] [-T [-]rtable] [-U [-]user] [number]
DESCRIPTION
top displays the top processes on the system and periodically updates
this information. If standard output is an intelligent terminal (see
below) then as many processes as will fit on the terminal screen are
displayed by default. Otherwise, a good number of them are shown (around
20). Raw CPU percentage is used to rank the processes. If number is
given, then the top number processes will be displayed instead of the
default.
top makes a distinction between terminals that support advanced
capabilities and those that do not. This distinction affects the choice
of defaults for certain options. In the remainder of this document, an
intelligent terminal is one that supports cursor addressing, clear
screen, and clear to end of line. Conversely, a dumb terminal is one
that does not support such features. If the output of top is redirected
to a file, it acts as if it were being run on a dumb terminal.
The options are as follows:
-1 Display combined CPU statistics for all processors on a single
line instead of one line per CPU. If there are more than 8 CPUs
detected in the system, this option is automatically enabled.
-b Use batch mode. In this mode, all input from the terminal is
ignored. Interrupt characters (such as `^C' and `^\') still have
an effect. This is the default on a dumb terminal, or when the
output is not a terminal.
-C Show command line arguments as well as the process itself.
-d count
Show only count displays, then exit. A display is considered to
be one update of the screen. This option allows the user to
select the number of displays to be shown before top
automatically exits. For intelligent terminals, no upper limit
is set. The default is 1 for dumb terminals.
-g string
Display only processes that contain string in their command name.
If displaying of arguments is enabled, the arguments are searched
too.
-H Show process threads in the display. Normally, only the main
process is shown. This option makes all threads visible.
-I Do not display idle processes. By default, top displays both
active and idle processes.
-i Use interactive mode. In this mode, any input is immediately
read for processing. See the section on INTERACTIVE MODE for an
explanation of which keys perform what functions. After the
command is processed, the screen will immediately be updated,
even if the command was not understood. This mode is the default
when standard output is an intelligent terminal.
-n Use non-interactive mode. This is identical to batch mode.
-o [-]field
Sort the process display area using the specified field as the
primary key. The field name is the name of the column as seen in
the output, but in lower case. The `-' prefix reverses the
order. The OpenBSD version of top supports cpu, size, res, time,
pri, pid, and command.
-p pid Show only the process pid.
-q Renice top to -20 so that it will run faster. This can be used
when the system is being very sluggish to improve the possibility
of discovering the problem. This option can only be used by
root.
-S Show system processes in the display. Normally, system processes
such as the pager and the swapper are not shown. This option
makes them visible.
-s time
Set the delay between screen updates to time seconds. The value
may be fractional, to permit delays of less than 1 second. The
default delay between updates is 5 seconds.
-T [-]rtable
Display only processes associated with the specified routing
table rtable. `T+' shows processes associated with all routing
tables. The `-' prefix hides processes associated with a single
routing table.
-t Display routing tables. By default, routing tables are not
shown.
-U [-]user
Show only those processes owned by username or UID user. The
prefix `-' hides processes owned by that user.
-u Do not take the time to map UID numbers to usernames. Normally,
top will read as much of the password database as is necessary to
map all the user ID numbers it encounters into login names. This
option disables all that, while possibly decreasing execution
time. The UID numbers are displayed instead of the names.
Both count and number fields can be specified as infinite, indicating
that they can stretch as far as possible. This is accomplished by using
any proper prefix of the keywords infinity, maximum, or all. The default
for count on an intelligent terminal is, in fact, infinity.
The environment variable TOP is examined for options before the command
line is scanned. This enables users to set their own defaults. The
number of processes to display can also be specified in the environment
variable TOP.
The options -I, -S, and -u are actually toggles. A second specification
of any of these options will negate the first. Thus a user who has the
environment variable TOP set to "-I" may use the command "top -I" to see
idle processes.
INTERACTIVE MODE
When top is running in interactive mode, it reads commands from the
terminal and acts upon them accordingly. In this mode, the terminal is
put in CBREAK, so that a character will be processed as soon as it is
typed. Almost always, a key will be pressed when top is between
displays; that is, while it is waiting for time seconds to elapse. If
this is the case, the command will be processed and the display will be
updated immediately thereafter (reflecting any changes that the command
may have specified). This happens even if the command was incorrect. If
a key is pressed while top is in the middle of updating the display, it
will finish the update and then process the command. Some commands
require additional information, and the user will be prompted
accordingly. While typing this information in, the user's erase and kill
keys (as set up by the command stty(1)) are recognized, and a newline
terminates the input.
These commands are currently recognized (^L refers to control-L):
h | ? Display a summary of the commands (help screen).
^L Redraw the screen.
<space>
Update the screen.
q Quit top.
+ Reset any filters put in place by the `g', `p', and `u'
interactive commands, or their command line equivalents, or any
process highlighting put in place by the `P' interactive command.
1 Toggle the display of per CPU or combined CPU statistics.
9 | 0 Scroll up/down the process list by one line.
( | ) Scroll up/down the process list by screen half.
C Toggle the display of process command line arguments.
d count
Show only count displays, then exit.
e Display a list of system errors (if any) generated by the last
kill or renice command.
g|/ string
Display only processes that contain string in their command name.
If displaying of arguments is enabled, the arguments are searched
too. `g+' or `/+' shows all processes.
H Toggle the display of process threads.
I | i Toggle the display of idle processes.
k [-sig] pid
Send signal -sig (TERM by default) to process pid. This acts
similarly to the command kill(1).
n|# count
Show count processes.
o [-]field
Sort the process display area using the specified field as the
primary key. The `-' prefix reverses the order. Values are the
same as for the -o flag, as detailed above.
P pid Highlight a specific process, selected by pid. `P+' removes
process highlighting.
p pid Show only the process pid. `p+' shows all processes.
r count pid
Change the priority (the nice) of a list of processes to count
for process pid. This acts similarly to the command renice(8).
S Toggle the display of system processes.
s time Set the delay between screen updates to time seconds.
T [-]rtable
Display only processes associated with the specified routing
table rtable. `T+' shows processes associated with all routing
tables. The `-' prefix hides processes associated with a single
routing table.
t Toggle the display of routing tables.
u [-]user
Show only those processes owned by username or UID user. `u+'
shows processes belonging to all users. The `-' prefix hides
processes belonging to a single user.
THE DISPLAY
The top few lines of the display show general information about the state
of the system, including the three load average numbers, the hostname,
the current time, the number of existing processes, the number of
processes in each state (starting, running, idle, stopped, zombie, dead,
and on processor), and a percentage of time spent in each of the
processor states (user, nice, system, spinning, interrupt, and idle). It
also includes information about physical and virtual memory allocation.
The load average numbers give the number of jobs in the run queue
averaged over 1, 5, and 15 minutes.
The remainder of the screen displays information about individual
processes. This display is similar in spirit to ps(1) but it is not
exactly the same. The following fields are displayed:
PID The process ID.
USERNAME The name of the process's owner.
TID The thread ID, used instead of USERNAME if -H is
specified.
UID Used instead of USERNAME if -u is specified.
PRI The current priority of the process.
NICE The nice amount (in the range -20 to 20).
SIZE The total size of the process (the text, data, and stack
segments).
RES The current amount of resident memory.
STATE The current state (one of start, run, sleep, stop, idle,
zomb, dead, or onproc). On multiprocessor systems, this
is followed by a slash and the CPU number on which the
process is bound.
WAIT A description of the wait channel the process is sleeping
on if it's asleep.
RTABLE The routing table, used instead of WAIT if -t is
specified.
TIME The number of system and user CPU seconds that the
process has used.
CPU The raw percentage of CPU usage and the default field on
which the display is sorted.
COMMAND The name (and arguments if -C is specified) of the
command that the process is currently running.
ENVIRONMENT
TOP User-configurable defaults for options.
FILES
/dev/kmem kernel memory
/dev/mem physical memory
/etc/passwd used to map user ID to user
/bsd kernel image
SEE ALSO
fstat(1), kill(1), netstat(1), ps(1), stty(1), systat(1), mem(4),
iostat(8), pstat(8), renice(8), vmstat(8)
AUTHORS
William LeFebvre, EECS Department, Northwestern University
CAVEATS
As with ps(1), top only provides snapshots of a constantly changing
system.
FreeBSD 14.1-RELEASE-p8 March 31, 2022 FreeBSD 14.1-RELEASE-p8