The Atari Compendium/The Atari Compendium (Toad Computers) (1994).iso/files/prgtools/mint/utilit~1/pstopls.zoo/top.doc

Text File | 1991-11-04 | 5.5 KB | 150 lines

NAME
    top - repeatedly display system status

SYNOPSYS
    top [-i] [-s seconds] [-w width] [-n nlines] [-r]

DESCRIPTION

"Top" is a program displays a periodically-updated picture of what's going
on in your system.

The display is a snapshot of system activity at periodic intervals. The top
line of the display shows the number of milliseconds included in the
interval, the percentage of that time counted by MiNT as "idle," the number
of processes in the system, the number of running processes, and the total
number of bytes used (the sum of the memory sizes of the processes listed).

Below that each process in the system is listed, one process per line.
The fields of this line have the following meanings:

    PID    The process ID of this process.

    PPID    The process ID of the parent of this process.

    PRI    The process' base priority.

    CUR    The process' current priority for adaptive scheduling.

    STATUS    The run state of the process: Wait, Sleep, Run, Exit,
        TSR, and Stop.  The Exit state means this process has
        terminated, but its parent has not received its exit code.
        The Run state includes the Ready state.

    SIZE    The amount of memory allocated to this process.

    TIME    The amount of time this process has run.  This is the sum
        of the user and system times of the process, displayed as
        MM:SS.FF (minutes, seconds, and fraction of a second) or
        HH:MM:SS (hours, minutes, and seconds) if the process has
        run one hour or more.

    %    The percentage of the time in this interval that this
        process accounted for.

    COMMAND    The command this process is running.

The number of processes displayed is limited by the number of lines on
your screen, or the 'nlines' option, whichever is less.

Either the PPID or the PRI and CURPRI will be displayed, not both.  Toggle
between these with the 'p' command (see below).

OPTIONS

    -n nlines
        Set the maximum number of processes to display.  This
        defaults to the length of your screen minus three for
        the status, input, and header lines.

    -r    Sort processes in DECREASING order of PID.  This (generally)
        puts more recent processes at the top.

    -s sleep
        Set the interval between updates to 'sleep' seconds.
        Default is 5.

    -w width
        Set the maximum width of a line to 'width'.  The arguments
        in the COMMAND field will be truncated so the line is no
        more than 'width' characters long.  The rest of the display
        (PID, STATUS, etc.) is not affected.  Default is the width
        of your screen.


COMMANDS WHILE RUNNING

    ?    Help - a brief reminder of what commands are available.

    k    Kill.  Prompts for arguments to the "kill" command, which
        are PID's preceded by an optional signal number. "123 124"
        sends signal 15 (SIGTERM) to processes 123 and 124. "-1 123
        124" sends signal 1 (SIGHUP) to them instead.

    n    Prompts for the maximum number of processes to display
        (nlines). This can be smaller than your screen size, but
        not  larger.

    p    Toggle between displaying the PPID of each process and that
        process' PRI and CURPRI values.

    q    Quit.

    r    Renice.  In response to the prompt, you should type in a
        "nice" delta value and one or more PID's.  Those process'
        "nice" values will be changed by that delta.

    s    Prompt for the number of seconds between intervals.

    w    Prompt for the width; the width can be more than the screen
        width, in which case long argument lists will take up
        multiple lines.

    ^L    (control-L) clear and repaint the display.

NOTES

This program uses curses and termcap.  Appropriate environment variables
must be set up.  The screen width and height, and thus the wraparound point
for wide lines and the maximum number of processes to display, are set at
startup time.

The "snapshot of your system" really is a snapshot: if things are moving
too fast, you can get blur.  If a process appears, runs, and exits during a
single interval, top will never see it.  Also, another strange-looking
thing can happen.  Let's say you know that process "A" will run, and after
it exits process "B" will run.  They may both appear on the same listing.
Finally, the sum of the percentages might be greater than 100.  All this is
caused by strobe, roundoff, and nonzero shutter time effects.

MiNT NOTES

The Run state includes the Ready state: since top itself is always the
running process when it gets a chance to check, having a separate name for
it conveys no information and is distracting.  So multiple processes
appear to be "running."

The COMMAND field is the concatenation of the "name" field of the process
and the command-line arguments in the process' basepage.  It can be wildly
inaccurate if the process is using its basepage as its DTA for a directory
search, or some other reason.

Processes are shown in the order they arrived from the directory search. If
there are more processes than lines on your screen (or your nlines value),
you'll see the older, less-interesting ones and lose the newer-more
interesting ones off the bottom.  That's why you can reverse the search
order.

AUTHOR

Top for MiNT was written in August, 1991 by Allan Pratt, Atari Corp.
(atari!apratt).  The idea for top came from the program of that name for
BSD UNIX systems. (UNIX is a trademark of AT&T.)  The source code is a
hacked-over version of ps, written in March of 1991 by Tony Reynolds
([e-mail]) and modified by Eric Smith (Mr. MiNT
himself).

TOP is placed unsupported in the public domain by Allan Pratt without let
or hindrance.  Please make the program and the source freely available.
Share and enjoy.