Cpu Usage in Top Batch Mode

CPU usage in top batch mode

On the first iteration, it is showing you the average CPU usage since system startup.

(Note that this is no longer the case for newer versions of top).

Assigning value to variable after parsing from top command

(top -i -b -n 1 | grep java |tr -s " " | cut -f 10 -d' ')

This worked for me :)

Linux's top CPU usage - always the same value

I didn't know it's called "iteration", using this keyword I've found a solution for the issue:

top command first iteration always returns the same result

Thank you for your help!

How to suppress the general information for top command

It's known as the "Summary Area" and i don't think there is a way at top initialization to disable those.

But while top is running, you can disable those by pressing l, t, m.

From man top:

 Summary-Area-defaults
  'l' - Load Avg/Uptime  On  (thus program name)
  't' - Task/Cpu states  On  (1+1 lines, see '1')
  'm' - Mem/Swap usage   On  (2 lines worth)
  '1' - Single Cpu       On  (thus 1 line if smp)

Linux top not printing full command name to file in batch mode as a nohup process

We can set the COLUMNS environment variable before the top command to increase the available width.

COLUMNS=1000 top -b -c -d1 -n2

The other way would be is to use ps to find the pid's of the processes by their names and specify the format of ps output.This output can be used to feed top to get the cpu usage for the process based on pid.

ps -eo pid,comms,args

comms = command name only and not the args

args = full argument list used to launch the process

Linux Top command giving output of both the cpu cores using command line

The Linux top command obtains its information from /proc/stat which is (somewhat) dependent upon the kernel version. Perhaps you could write a program which reads from that. Here is a sample from a 2.6.32 system with 20 cores:

cpu  46832272 794980 8521784 1312627944 853989 247 34947 0 0
cpu0 6404288 173468 806918 60455445 377313 1 1799 0 0
cpu1 2980140 137898 937163 64278592 68373 0 118 0 0
cpu2 5099227 86676 841568 62395343 27685 0 64 0 0
cpu3 11255325 20062 767603 56427120 9388 0 85 0 0
cpu4 2618170 1002 501629 65394095 4369 0 62 0 0
cpu5 635453 867 154898 67725523 2981 212 58 0 0
cpu6 343657 32 66510 68113208 2769 0 64 0 0
cpu7 327935 688 38431 68158263 1703 0 55 0 0
cpu8 118687 78 27436 68382190 1992 0 33 0 0
cpu9 329990 49 42224 68138515 1643 0 49 0 0
cpu10 3462177 160918 814788 63701724 202763 3 5444 0 0
cpu11 3006524 112533 484490 64877526 37455 0 6840 0 0
cpu12 2696919 61285 695966 65004324 17277 0 133 0 0
cpu13 3453005 34509 957663 64035215 10938 0 101 0 0
cpu14 2068954 2039 679830 65764151 6418 0 50 0 0
cpu15 628390 159 367213 67531841 2593 0 41 0 0
cpu16 331139 77 76690 68120995 2971 0 51 0 0
cpu17 616895 2482 182239 67595814 70070 29 19797 0 0
cpu18 343472 51 38712 68148369 2481 0 46 0 0
cpu19 111916 96 39803 68379681 2797 0 47 0 0
intr 1991637171 173 2 0 0 2 0 0 0 1 0 0 0 4 0 0 0 0 1 56 1416833 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1644 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 2285 0 0 0 0 0 0 0 3211641 4799987 3235 31624105 11000098 0 ...
ctxt 3201588026
btime 1460672984
processes 2430161
procs_running 2
procs_blocked 0
softirq 1391193131 0 626556634 166050 33864038 3892307 0 11210298 67287467 2880340 645335997

According to the man page (man 5 proc then search for /proc/stat), the lines for cpu entries are:

• The amount of time, measured in units of USER_HZ (1/100ths of a second on most architectures, use sysconf(_SC_CLK_TCK) to obtain the right value), that the system spent in user mode, user mode with low priority (nice), system mode, and the idle task, respectively. The last value should be USER_HZ times the second entry in the uptime pseudo-file.
• iowait - time waiting for I/O to complete; irq - time servicing interrupts; softirq - time servicing softirqs.
• steal - stolen time, which is the time spent in other operating systems when running in a virtualized environment
• guest, which is the time spent running a virtual CPU for guest operating systems under the control of the Linux kernel.
• guest_nice time spent running a niced guest (virtual CPU for get operating systems under the control of the Linux kernel).

I looked at a 4.4.6 kernel system too. The cpu entries have the tenth item.

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