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NAME
top - display and update information about the top cpu processes
SYNOPSIS
top [ -CISTbcinquv ] [ -dcount ] [ -stime ] [ -ofield ] [ -Uusername ]
[ number ]
DESCRIPTION
Top displays the top 10 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 Turn off the use of color in the display.
-I Do not display idle processes. By default, top displays both
active and idle processes.
-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.
-T List all available color tags and the current set of tests used
for color highlighting, then exit.
-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 the full command line for each process. Default is to show
just the command name. This option is not supported on all
platforms.
-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.
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-n Use "non-interactive" mode. This is indentical to "batch" mode.
-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.
-u 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 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 "?".
-dcount
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. For intelligent terminals, no upper limit
is set. The default is 1 for dumb terminals.
-stime
Set the delay between screen updates to time seconds. The
default delay between updates is 5 seconds.
-ofield
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.
-Uusername
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
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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.
These commands are currently recognized (^L refers to control-L):
^L Redraw the screen.
h or ?
Display a summary of the commands (help screen). Version
information is included in this display.
q Quit top.
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.
n or #
Change the number of processes to display (prompt for new
number).
s Change the number of seconds to delay between displays (prompt
for new number).
k Send a signal ("kill" by default) to a list of processes. This
acts similarly to the command kill(1)).
r Change the priority (the "nice") of a list of processes. This
acts similarly to the command renice(8)).
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.
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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.
e Display a list of system errors (if any) generated by the last
kill or renice command.
i (or I) Toggle the display of idle processes.
c Toggle the display of the full command line.
C Toggle the use of color in the display.
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 few lines of the display show general information about the
state of the system, including the last process id assigned to a
process (on most systems), the three load averages, the current time,
the number of existing processes, the number of processes in each
state (sleeping, running, starting, zombies, and stopped), and a
percentage of time spent in each of the processor states (user, nice,
system, and idle). It also includes information about physical and
virtual memory allocation.
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).
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.
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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
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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), stty(1), mem(4), renice(8)
HPUX 10 INFORMATION
The process information layout has changed slightly since previous
versions. The CPU percentage column reports weighted cpu as
calculated directly by the kernel. The WCPU column is no longer
present in the output and a TTY column has been added to indicate the
name of the process's controlling terminal. The definition of an idle
process has been relaxed to include those processes that have only
just gone to sleep.
This version of top does not display a per-cpu breakdown of processor
state. Perhaps a later version will add this sophistication across
all platforms.
The HP/UX 10 port has greatly benefitted from the diligent efforts of
the following individuals: John Haxby <john_haxby@hp.com>, Rich
Holland <holland@synopsys.com>, and <kevin@mcl.ucsb.edu>.
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