A great list of commands to extract very useful system information for your Raspberry Pi. Personally I like to put a lot in my .bashrc file to remind me which system I am SSHing to. Here is my running "bash config" -- https://gist.github.com/SkaTeMasTer/9954a8ffd6bfc552969d38f5562f187b

very-useful-RPI3-system-info.txt

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LIST OF LINUX COMMANDS FOR GATHERING PI SPECIFICATIONS
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“cat /proc/meminfo” (Memory Info)
“cat /proc/cpuinfo” (CPU Info)
“cat /proc/partitions” (Disk Partition Info)
“cat /proc/version” (Linux Version Info)
“cat /boot/cmdline.txt” (Boot Parameters)
“cat /proc/filesystems” (File System Info)
“cat /etc/passwd” (Username & Password Info)
“free -h” (Memory Stats Info)
“hostname -I” (Hostname Info)
“lsusb” (USB Devices info)
“lscpu” (CPU Info)
“vcgencmd measure_temp” (Temperature Info)
“vcgencmd get_mem arm && vcgencmd get_mem gpu” (Memory Size Info)
“uname -m” (Architecture Info)
“uname -n” (Hostname Info)
“uname -v” (Kernel Version Info)
“uname -r” (Kernel Release Info)
“df -h” (Disk Space Info)
“df /” (Current Disk Info)
“date” (Date Info)
“ip addr” (IP Info)
“ifconfig” (Network Info)
“iwconfig” (Wireless Info)
“last” (Session Info)
“lastlog” (User Login Info)
“pwd” (Directory Info)
“History” (Recent Shell Command Info)
“dmesq” (Kernel Messages Info)
“ls -l” (Directory Files Info)
“iwlist wlan0 scan” (Wireless Network Info)
“iwlist wlan0 scan | grep ESSID” (Wireless SSID Info)
“top” (Running Process Info)
“lsblk” (Block Devices Info)
“ps” (Processes Info)
“nslookup google.com” (DNS Lookup Info)