Useful Linux Bash Commands

Get disk information

$ sudo lsblk -io KNAME,TYPE,SIZE,MODEL
KNAME     TYPE  SIZE MODEL
nvme0n1   disk   20G Amazon Elastic Block Store
nvme0n1p1 part   20G
nvme1n1   disk 46.6G Amazon EC2 NVMe Instance Storage
nvme1n1p1 part 46.6G
dm-0      lvm  46.6G
nvme2n1   disk   20G Amazon Elastic Block Store
nvme2n1p1 part   20G

Get Linux OS information

$ cat /etc/os-release
NAME="CentOS Linux"
VERSION="7 (Core)"
ID="centos"
ID_LIKE="rhel fedora"
VERSION_ID="7"
PRETTY_NAME="CentOS Linux 7 (Core)"
ANSI_COLOR="0;31"
CPE_NAME="cpe:/o:centos:centos:7"
HOME_URL="https://www.centos.org/"
BUG_REPORT_URL="https://bugs.centos.org/"

CENTOS_MANTISBT_PROJECT="CentOS-7"
CENTOS_MANTISBT_PROJECT_VERSION="7"
REDHAT_SUPPORT_PRODUCT="centos"
REDHAT_SUPPORT_PRODUCT_VERSION="7"

Memory Usage

$ free -h
              total        used        free      shared  buff/cache   available
Mem:           3.5G        2.3G        116M        440K        1.1G        968M
Swap:            0B          0B          0B

Get current date time in different formats

# Get DateTime in UTC
$ date -u
Sun Sep 11 14:49:27 UTC 2021

# Get DateTime in ISO-8601 format
$ date +"%Y-%m-%dT%H:%M:%S%:z"
2021-09-11T14:49:47+00:00

# Get DateTime in a specific timezone
$ TZ=":US/Eastern" date '+%Y-%m-%d %H:%M:%S'
2021-09-11 10:53:02

Convert Epoch to DateTime

# Mac OS
❯ date -r 1663004743
Mon Sep 12 23:15:43 IST 2022

# Linux
$ date -d @$((1663004743))
Mon Sep 12 17:45:43 UTC 2022

Monitor CPU temparature

# Mac OS
sudo powermetrics --samplers smc | grep -i "CPU die temperature"