Can I view system stats in the Terminal?

Question

The widget iStat Pro allows to monitor different system stats like

• CPU usage
• network bandwidth in/out
• memory usage
• ...

How can I view such system stats in the Terminal?

Answer 1

Depending on what you want displayed there are several options available using Terminal:

• top: real-time sorted display of running processes such as memory and CPU usage
• iostat: I/O summary statistics for terminal, device and CPU operations
• vm_stat: Mach virtual memory statistics
• diskutil list: disk/volume capacity
• df: used/free space on mounted partitions
• fs_usage: real-time file activity for both disk and network
• nettop: updated information about the network (a bit like top for net I/O)
• w: who is logged in and what they are doing; plus a brief system load summary
• ifconfig and ipconfig: network interface and IP protocol details

Most of these commands have a huge list of options.  It's probably best to consult the man pages for details.

I usually rely on:

• top -u -s 10 to identify CPU-hogging processes;
• fs_usage -f filesys or fs_usage -f network to identify processes generating a lot of disk/network load.

Answer 2

The iStats ruby gem lets you see the CPU temperature via the command-line.

Installation

$ gem install iStats

Usage

$ istats

Answer 3

You can use top. It'll show CPU & RAM usage together with all the processes. It'll also show you network packets in/out, and discs data read/written.

Answer 4

The above are great commands. Also, I like to use

$ du -ks *

To show how much disk space all the folders below my current directory are using.

This command lists the top 10 directories in order of size:

$ du -sh * | sort -nr | head -10

For an overall system stats tool, I like the python glances better than top:

https://nicolargo.github.io/glances/

This is how you can install it on Debian/Ubuntu:

$ sudo apt-get install glances

This is how you can install it on CentOS/Red Hat:

# yum  install glances

Answer 5

If you are having network problems, especially with a server exposed to the Internet, lsof(1) can be extremely useful. It lists all open files.

For example, lsof | fgrep '/Library/WebServer/ will show you all the files that are open on your web server. I've been using this a lot to find and ban "leeches" and "bots" who are reducing my bandwidth by automatically sucking down file after file.

Answer 6

My preferred way to see CPU usage with a single command that returns instantly is

ps -axro pcpu | awk '{sum+=$1} END {print sum}'

-ax: all processes, including non-terminal processes and ones you don't own.

-r: sort by cpu usage

-o pcpu: only output the %cpu field. %cpu is a 1-minute average of the process, but will only average over the lifetime of the process if its lifetime is <1min.

awk: sum the first column in each line and print the sum at the end.

This is a per-core CPU metric, so on a 12 core CPU you can get up to 1200; you're not capped at 100.

Answer 7

Here are two commands for determining your local and public IP:

Local IP

ipconfig getifaddr en1

This is when using Wi-Fi. For ethernet use en0.

Public IP

curl whatismyip.org