top

List running processes on the system, in sorted order.
Periodically displays a list of processes on the system in sorted order. The default key for sorting is pid, but other keys can be used instead.

Syntax
      top    [-a | -d | -e | -c mode]
             [-F | -f]
             [-h]
             [-i interval]
             [-l samples]
             [-ncols columns]
             [-o key] [-O skey]
             [-R | -r]
             [-S]
             [-s delay]
             [-n nprocs]
             [-stats keys]
             [-pid processid]
             [-user username]
             [-U username]
             [-u]

Options

Command line option specifications are processed from left to right. Options can be specified more than once. If conflicting options are specified, later specifications override earlier ones. This makes it viable to create a shell alias for top with preferred defaults specified, then override those preferred defaults as desired on the command line.

       -a     Equivalent to -c a.

       -c mode
       Set event counting mode to mode.  The supported modes are:

           a  Accumulative mode. Count events  cumulatively,  starting
              at the launch of top. Calculate CPU usage and CPU time since
              the launch of top.

           d  Delta mode. Count events relative to the previous sample.
              Calculate CPU usage since the previous sample.

           e  Absolute mode. Count events using absolute counters.

           n  Non-event mode (default).  Calculate CPU usage since the
              previous sample.

       -d   Equivalent to -c d.
       -e   Equivalent to -c e.

       -F   Do not calculate statistics on shared libraries, also  known  as
            frameworks.   This substantially reduces the amount of processor
            time top consumes.

       -f   Calculate statistics on shared libraries, also known as frameworks
            (default).

       -h   Print command-line help and exit.

       -i interval
            Update framework (-f) info every interval samples

       -l samples
            Use logging mode and display samples samples, even if standard
            output is a terminal. 0 is treated as infinity. Rather than
            redisplaying, output is periodically printed in raw form.

       -ncols  columns
            Display columns when using logging mode. The default is infinite.
            The number must be > 0 or an error will occur.

       -n nprocs
            Only display up to nprocs processes. nprocs can be specified
            as the last command line argument without the -n flag preceding it.
            However, doing so is deprecated command line usage.

       -O skey
            Use skey as a secondary key when ordering the process display.
            See -o for key names (pid is default).

       -o key
            Order the process display by sorting on key in descending  order.
            A +  or - can be prefixed to the key name to specify ascending or
            descending order, respectively.

            Some supported keys (see 'man top' for a full list):

              command  Command name.
              cpu      CPU usage.
              cpu_me   CPU time charged to me by other processes.
              cpu_others   CPU time charged to other processes by me.
              csw      Number of context switches.
              kshrd    Shared kernel memory size
              pid      Process ID (default).
              rprvt    Resident private address space size.
              time     Execution time.
              threads  alias: th   No. of threads (total/running).
              uid      User ID.
              user     Username. Also alias: username
              vprvt    Private address space size.
              vsize    Total memory size.

       -R   Do not traverse and report the memory object map for each process.
            This substantially reduces the amount of processor time top consumes.

       -r   Traverse and report the memory object map for each process.

       -S   Display information about swap usage and purgeable memory.

       -s delay
            Set the delay between updates to delay seconds. The default delay
            between updates is 1 second.

       -stats keys
            Only display the comma separated statistics. See the -o flag for the valid keys.

       -pid processid   Only display processid in top.

       -U user
       -user user
            Only  display processes owned by user.
            Either the username or uid number can be specified.

       -u   This is an alias equivalent to: -o cpu -O time.

Performance vs. Accuracy

Calculating detailed memory statistics is fundamentally resource-intensive. To reduce the cpu usage in top, the -i parameter has been introduced to allow the user to tune this tradeoff. With the default value of 10, framework stats will be updated once every 10 samples. Specifying -i 1 will result in the most accurate display, at the expense of system resources.

Examples

Display processes sorted by CPU usage, updating every 5 seconds:

$ top -ocpu -s 5

Run top in delta mode:

$ top -c d

Run top in event counter mode:

$ top -ce

Show deltas for network and paging activity, updating every 10 seconds:

$ top -d -u -s 10

Show a detailed memory object map for pid #630:

$ top -r -l 1 -s 0 -stats pid,command,rprvt,vsize,vprvt,kprvt,kshrd -pid 630 | sed 1,11d

PID COMMAND RPRVT VSIZE VPRVT KPRVT KSHRD
630 loginwindow 13M 393G 1398M 592K -1M

“Venice is like eating an entire box of chocolate liqueurs at one go” ~ Truman Capote

Related macOS commands

Local man page: top - Command line help page on your local machine.
kill - Stop a process from running.
signal(3) - software signal facilities.