Editing Top (software) (section)

== Example ==

The first 5 rows overview the entire system.

<syntaxhighlight lang="text">
top - 14:21:23 up 2 days, 21:40, 44 users,  load average: 14.44, 14.13, 14.64
        |                   |    |                         |
      <time>    <system uptime> <user count>         <load average for the past 1, 5, 15 minutes>

Tasks: 1552 total,   8 running, 1544 sleeping,   0 stopped,   0 zombie

%Cpu(s):  9.6 us,  0.7 sy,  0.0 ni, 89.5 id,  0.0 wa,  0.0 hi,  0.2 si,  0.0 st
              |        |        |        |        |        |        |         '------.
           <user>  <system>  <nice>  <idle> <IOWait> <hardware/software interrupt> <steal time>

MiB Mem : 1031911.+total, 368915.2 free, 172285.0 used, 490711.5 buff/cache
MiB Swap:   2048.0 total,   2048.0 free,      0.0 used. 807110.1 avail Mem
</syntaxhighlight>

<code>[[Load (computing)|load average]]</code> is the exponential moving average of the run-queue length over the past 1/5/15 minutes. The run-queue includes both processes being run and waiting to be run. At complete utilization with no task switching, the load average is equal to the number of CPUs.<ref name="drdobbs">{{cite web |last=Walker |first=Ray |date=1 December 2006 |title=Examining Load Average |url=http://www.linuxjournal.com/article/9001 |access-date=13 March 2012 |work=Linux Journal}}</ref>

<code>Tasks</code> counts the processes their statuses.

<code>%Cpu(s)</code> counts the percentage of CPU usage, broken down into categories.

<code>MiB Mem</code>: Memory usage in units of [[mebibyte]]. The <code>buff/cache</code> is for memory used by [[Registered memory|buffers]] and [[Cache (computing)|cache]].

<code>MiB Swap</code>: Swap space usage in units of [[mebibyte]]. If the system needs more memory resources and the RAM is full, inactive pages in memory are moved to the swap space. In this snapshot, there's a total of 2048 MiB of swap, all free, indicating that no swapping is occurring, which is good for performance.

<code>avail Mem</code>: The amount of memory available for new applications, without swapping. This considers not just the unused RAM, but also the memory that can be reclaimed from RAM caches.

The rest of the text provides a table with each row being a [[Process (computing)|process]], with the following columns often used out of many possible columns (the choice and ordering of columns are configurable):<ref>[https://gitlab.com/procps-ng/procps/-/blob/master/man/top.1?ref_type=heads top(1) - Linux man page]</ref>

<syntaxhighlight lang="text">
    PID USER      PR  NI    VIRT    RES    SHR S  %CPU  %MEM     TIME+ COMMAND
      1 root      20   0    2456   1612   1500 S   0.0   0.0   0:00.07 init(Ubuntu)
      4 root      20   0    2456      4      0 S   0.0   0.0   0:00.00 init
 656403 user2     20   0   80.0g   3.6g 370000 S 100.0   0.4   1594:38 python3
2024198 longnam+  20   0   50.5g   4.7g 609200 S   1.6   0.5 204:46.85 long-name-proc
2056804 longnam+  20   0  237.1g  31.1g  23.1g S 136.8   3.1  69:54.11 python3
</syntaxhighlight>

* <code>PID</code>: [[Process identifier|Process ID]], a unique number identifying each running process.
* <code>USER</code>: The [[User (computing)|user]] who started the process. If the username is too long, it is cut-off with a <code>+</code> at the end.
* <code>PR</code>: Real-time [[Scheduling (computing)|priority]] of the task, computed by the system scheduler. ''Lower'' PR numbers are considered more important by the scheduler and more likely to be scheduled, which means it tends to have more CPU-time per real-time.
* <code>NI</code>: The [[Nice (Unix)|''niceness'']] of the task, manually set by users and administrators to influence the real-time priority. A lower nice value tends to favor the process, and a higher nice value tends to disfavor the process. It ranges from -20 (most favored) to 19 (least favored).
* <code>VIRT</code>: [[Virtual memory]] size of the process. This includes all memory that the process can access, including memory that is swapped out, memory that is allocated but not used, and shared memory.
* <code>RES</code>: [[Resident set size]], the portion of a process's memory that is held in RAM. Compared with <code>VIRT</code>, this excludes memory that is swapped out, not yet used, or shared.
* <code>SHR</code>: [[Shared memory]] size: how much of the RAM claimed by the process is sharable with other processes.
* <code>S</code>: Status of process. The status can be: 
** <code>R</code> for running
** <code>S</code> for sleeping
** <code>I</code> for idle
** <code>D</code> for disk sleep (uninterruptible)
** <code>Z</code> for [[Zombie process|zombie]] (terminated but not reaped by its parent)
** <code>T</code> for stopped by a [[Job control (Unix)|job control signal]] or <code>t</code> for stopped by [[debugger]] during [[Tracing (software)|tracing]].
* <code>%CPU</code>: The percentage of the CPU time that the process is currently using.
* <code>%MEM</code>: The percentage of the physical RAM used by the process.
* <code>TIME+</code>: The total CPU time the task has used since it started. This is shown in <code>minutes:seconds</code> . The plus sign in <code>TIME+</code> means that it is accurate to 0.01 second. If it shows <code>TIME</code> then it is accurate to 1 second.
* <code>COMMAND</code>: The command line argument that started the process. Unlike <code>USER</code> , if the command is too long, it is cut-off without a <code>+</code> at the end.