TOP(1) User Commands TOP(1)

NAME

top - display and update information about the top cpu processes

SYNOPSIS

top [ -CISTabcinqtuv ] [ -dcount ] [ -mmode ] [ -ofield ] [ -stime ]
[ -Uusername ] [ number ]

DESCRIPTION

Top displays the top 30 processes on the system and periodically
updates this information. 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.

OPTIONS

-C, --color
Turn off the use of color in the display.

-I, --idle-procs
Do not display idle processes. By default, top displays both
active and idle processes.

-S, --system-procs
Show system processes in the display. Normally, system
processes such as the pager and the swapper are not shown.
This option makes them visible.

-T, --tag-names
List all available color tags and the current set of tests
used for color highlighting, then exit.

-a, --all
Show all processes for as long as possible. This is shorthand
for "-d all all". This option is especially handy in batch
mode.

-b, -n, --batch
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, --full-commands
Show the full command line for each process. Default is to
show just the command name. This option is not supported on
all platforms.

-i, --interactive
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.

-q, --quick
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.

-t, --threads
Show individual threads on separate lines. By default, on
systems which support threading, each process is shown with a
count of the number of threads. This option shows each thread
on a separate line. This option is not supported on all
platforms.

-u, --uids
Do not take the time to map uid numbers to usernames.
Normally, top will read as much of the file "/etc/passwd" 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.

-v, --version
Write version number information to stderr then exit
immediately. No other processing takes place when this option
is used. To see current revision information while top is
running, use the help command "?".

-d count, --displays 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 he wants to see before top
automatically exits. Any proper prefix of the words
"infinity", "maximum", or "all" can be used to indicate an
infinite number of displays. The default for intelligent
terminals is infinity. The default for dumb terminals is 1.

-m mode, --mode=mode
Start the display in an alternate mode. Some platforms
support multiple process displays to show additional process
information. The value mode is a number indicating which mode
to display. The default is 0. On platforms that do not have
multiple display modes this option has no effect.

-o field, --sort-order=field
Sort the process display area on the specified field. The
field name is the name of the column as seen in the output,
but in lower case. Likely values are "cpu", "size", "res",
and "time", but may vary on different operating systems. Note
that not all operating systems support this option.

-s time, --delay=time
Set the delay between screen updates to time seconds. The
default delay between updates is 5 seconds.

-U username, --user=username
Show only those processes owned by username. This option
currently only accepts usernames and will not understand uid
numbers.

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 a user to set his or her own
defaults. The number of processes to display can also be specified
in the environment variable TOP. The options -C, -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) are recognized, and a newline terminates the input.
Note that a control-L (^L) always redraws the current screen and a
space forces an immediate update to the screen using new data.

These commands are currently recognized:

h or ? Display a summary of the commands (help screen). Version
information is included in this display.

C Toggle the use of color in the display.

c Display only processes whose commands match the specified
string. An empty string will display all processes. This
command is not supported on all platforms.

d Change the number of displays to show (prompt for new number).
Remember that the next display counts as one, so typing d1
will make top show one final display and then immediately
exit.

f Toggle the display of the full command line.

H Toggle the display of threads on separate lines. By default,
on systems which support threading, each process is shown with
a count of the number of threads. This command shows each
thread on a separate line. This command is not supported on
all platforms.

i (or I) Toggle the display of idle processes.

k Send a signal ("kill" by default) to a list of processes.
This acts similarly to the command kill(1)).

M Sort display by memory usage. Shorthand for "o size".

m Change to a different process display mode. Some systems
provide multiple display modes for the process display which
shows different information. This command toggles between the
available modes. This command is not supported on all
platforms.

N Sort by process id. Shorthand for "o pid".

n or # Change the number of processes to display (prompt for new
number).

o Change the order in which the display is sorted. This command
is not available on all systems. The sort key names vary fron
system to system but usually include: "cpu", "res", "size",
"time". The default is cpu.

P Sort by CPU usage. Shorthand for "o cpu".

q Quit top.

r Change the priority (the "nice") of a list of processes. This
acts similarly to the command renice(1)).

s Change the number of seconds to delay between displays (prompt
for new number).

T Sort by CPU time. Shorthand for "o time".

U Toggle between displaying usernames and uids.

u Display only processes owned by a specific username (prompt
for username). If the username specified is simply "+", then
processes belonging to all users will be displayed.

THE DISPLAY

The actual display varies depending on the specific variant of Unix
that the machine is running. This description may not exactly match
what is seen by top running on this particular machine. Differences
are listed at the end of this manual entry.

The top lines of the display show general information about the state
of the system. The first line shows (on some systems) the last
process id assigned to a process, the three load averages, the system
uptime, and the current time. The second line displays the total
number of processes followed by a breakdown of processes per state.
Examples of states common to Unix systems are sleeping, running,
starting, stopped, and zombie. The next line displays a percentage
of time spent in each of the processor states (typically user, nice,
system, idle, and iowait). These percentages show the processor
activity during the time since the last update. For multi-processor
systems, this information is a summation of time across all
processors. The next line shows kernel-related activity (not
available on all systems). The numbers shown on this line are per-
second rates sampled since the last update. The exact information
displayed varies between systems, but some examples are: context
switches, interrupts, traps, forks, and page faults. The last one or
two lines show a summary of memory and swap activity. These lines
vary between systems.

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 columns displayed by top will differ slightly
between operating systems. Generally, the following fields are
displayed:

PID The process id.

USERNAME
Username of the process's owner (if -u is specified, a UID
column will be substituted for USERNAME).

THR The number of threads in the processes (this column may also
be labeled NLWP).

PRI Current priority of the process.

NICE Nice amount in the range -20 to 20, as established by the use
of the command nice.

SIZE Total size of the process (text, data, and stack) given in
kilobytes.

RES Resident memory: current amount of process memory that resides
in physical memory, given in kilobytes.

STATE Current state (typically one of "sleep", "run", "idl", "zomb",
or "stop").

TIME Number of system and user cpu seconds that the process has
used.

CPU Percentage of available cpu time used by this process.

COMMAND
Name of the command that the process is currently running.

COLOR

Top supports the use of ANSI color in its output. By default, color
is available but not used. The environment variable TOPCOLORS
specifies colors to use and conditions for which they should be used.
At the present time, only numbers in the summay display area can be
colored. In a future version it will be possible to highlight numbers
in the process display area as well. The environment variable is the
only way to specify color: there is no equivalent command line
option. Note that the environment variable TOPCOLOURS is also
understood. The British spelling takes precedence. The use of color
only works on terminals that understand and process ANSI color escape
sequences.

The environment variable is a sequence of color specifications,
separated by colons. Each specification takes the form
tag=min,max#code where tag is the name of the value to check, min and
max specify a range for the value, and code is an ANSI color code.
Multiple color codes can be listed and separated with semi-colons. A
missing min implies the lowest possible value (usually 0) and a
missing max implies infinity. The comma must always be present. When
specifying numbers for load averages, they should be multiplied by
100. For example, the specification 1min=500,1000#31 indicates that
a 1 minute load average between 5 and 10 should be displayed in red.
Color attributes can be combined. For example, the specification
5min=1000,#37;41 indicates that a 5 minute load average higher than
10 should be displayed with white characters on a red background. A
special tag named header is used to control the color of the header
for process display. It should be specified with no lower and upper
limits, specifically header=,# followed by the ANSI color code.

You can see a list of color codes recognized by this installation of
top with the -T option. This will also show the current set of tests
used for color highligting, as specified in the environment.

AUTHOR

William LeFebvre

ENVIRONMENT

TOP user-configurable defaults for options. TOPCOLORS
color specification

BUGS

As with ps(1), things can change while top is collecting information
for an update. The picture it gives is only a close approximation to
reality.

SEE ALSO

kill(1), ps(1), renice(1), stty(1), mem(4D)

SUNOS 5 NOTES
CPU percentage is calculated as a fraction of total available
computing resources. Hence on a multiprocessor machine a single
threaded process can never consume cpu time in excess of 1 divided by
the number of processors. For example, on a 4 processor machine, a
single threaded process will never show a cpu percentage higher than
25%. The CPU percentage column will always total approximately 100,
regardless of the number of processors.

The kernel summary line shows the following information, all
displayed as a per-second rate:

ctxsw Context switches.

trap Number of traps.

intr Number of interrupts.

syscall Number of system calls.

fork Number of forks and vforks.

flt Number of page faults.

pgin Number of kilobytes paged in to physical memory.

pgout Number of kilobytes paged out from physical memory.

The memory summary line displays the following:

phys mem Total amount of physical memory that can be allocated
for use by processes (it does not include memory
reserved for the kernel's use).

free mem The amount of unallocated physical memory.

total swap The total amount of swap area allocated on disk.

free swap The amount of swap area on disk that is still
available.

Unlike previous versions of top, the swap figures will differ from
the summary output of swap(8) since the latter includes physical
memory as well.

The column NLWP indicates the number of lightweight processes in a
process. This usually corresponds to the number of threads in that
process.

The display of individual threads can be toggled with the synonymous
commands t and H. Information about state, priority, CPU time and
percent CPU are shown for each individual thread. Other information
is identical for all threads in the same process. In this display
the column LWP replaces NLWP and shows the lightweight process id.
The column names LWP and NLWP are consistent with ps(1).

In BSD Unix, process priority was represented internally as a signed
offset from a zero value with an unsigned value. The "zero" value
was usually something like 20, allowing for a range of priorities
from -20 to 20. As implemented on SunOS 5, older versions of top
continued to interpret process priority in this manner, even though
it was no longer correct. Starting with top version 3.5, this was
changed to agree with the rest of the system.

Long options are not currently available in Solaris.

The SunOS 5 (Solaris 2) port was originally written by Torsten Kasch,
<torsten@techfak.uni-bielefeld.de>. Many contributions have been
provided by Casper Dik <Casper.Dik@sun.com>. Support for multi-cpu,
calculation of CPU% and memory stats provided by Robert Boucher
<boucher@sofkin.ca>, Marc Cohen <marc@aai.com>, Charles Hedrick
<hedrick@geneva.rutgers.edu>, and William L. Jones <jones@chpc>.

COPYRIGHT

Copyright (C) 1984-2007 William LeFebvre. For additional licensing
information, see http://www.unixtop.org/license/

4th Berkeley Distribution Local TOP(1)