Check the hardware and system information in Linux.

To List all the HARDWARE in your current System

Example:
#lshw

To make the output short with lshw command 

Example:
#lshw -short 

To search by the TYPE of Hardware 

Example:
#lshw -class cpu          ** This is for CPU **
#lshw -class memory  ** This is for RAM **
#lshw -class disk          ** This is for DISK **
#lshw -class volume    ** This is for partition **
#lshw -class network  ** This is for Network **

To hide the sensitive Information like serail number. 

Example:
#lshw -sanitize
#lshw -class cpu -sanitize 
#lshw -class memory -sanitize 
#lshw -class disk  -sanitize
#lshw -class volume  -sanitize
#lshw -class network  -sanitize

To get the output in HTML Format 

Example:
#lshw -html

** To take a html format in one file **
#lshw -html > hardware_list.html 

To get the output in XML Format 

Example:
#lshw -xml

** To take a xml format in one file **
#lshw -xml > hardware_list.xml 

To get the output in JSON Format 

Example:
#lshw -json

** To take a json format in one file **
#lshw -json > hardware_list.json 

Q. How we can list the partition in the disk using fdisk.

Syntax:
#fdisk -[option]

Command:
#fdisk -l

Q. How we can list the partition of a particular Disk.

Syntax:
#fdisk -[option] [disk_partion]

Command:
#fdisk -l  /dev/sdb

Q. How we can see a Colourful output.

Syntax:
#fdisk -[option]=[never/always/auto]

Command:
# fdisk -l -L=never
# fdisk -l --color=always

Q. How to get the output of a specific column using fdisk command in Linux.

Syntax:
#fdisk -[option] -o [cloumn_name]

Command:
# fdisk -l -o Device,UUID,Size,type

Q. How to get the size of disk and from its partitions.

Syntax:
#fdisk -[option] [disk/disk_partition]

Command:
# fdisk -s /dev/sda
# fdisk -s /dev/sda1

Q. How to get the disk details by its disk label type.

Syntax:
#fdisk -[option] [disk_label]

Command:
# fdisk -l -t gpt

Q. How to get the output by it's units with fdisk command.

Syntax:
#fdisk -[option]=[units]

Command:
# fdisk -l -u=sectors
# fdisk -l -u=cylinders

To check the size of files and folder in human readable format

Syntax:
du [option] [argument]

Example:
#du -h files
#du -h folders

To check the output in a single line.

Syntax:
du [option]

Example:
#du --null
#du -0

To check all files and folder in Linux.

Syntax:
du [option]

Example:
#du -a
#du --all

To check all files and folder in Block size.

Syntax:
du [option] [argument]

Example:
#du -B k  -- o/p will be in KB.
#du -B m -- o/p will be in MB.
#du -B g  --  o/p will be in GB.

To check the total size of the current directory.

Syntax:
du [option]

Example:
#du -c
#du --total

To check the depth or level for a directory .

Syntax:
du [option] [levels]

Example:
#du -d 1 -- for level one directory.
#du -d 2 -- for level two directory.
#du -d 3 -- for level three directory.

To check the inodes instead of block size.

Syntax:
du [option]

Example:
#du --inodes

To check the size of it's directory only not it's sub-directory.

Syntax:
du [option]

Example:
#du -S

Displat only the total of an each arugment.

Syntax:
du [option]

Example:
#du -s

To Set the threshold size  

Syntax:
du [option] [size]

Example:
#du -t 5k //Show only those files and folders whose size is greater that 5 KB.  
#du --threshold=10k //Show only those files and folders whose size is greater that 10 KB.

To show the modification time with size.

Syntax:
du [option] [size]

Example:
#du --time

To exclude the size of the file.

Syntax:
du [option]=[directory]

Example:
#du --exclude=level_1

1. To check the Disk Space.

Example:
#df 

2. To check the Disk Space in human readable format.

Syntax:
df [option]

Example:
#df -h

3. To check the type of file System.

Syntax:
df [option]

Example:
#df -T

4. To check with particular file system.

Syntax:
df [option] [arugment]

Example:
#df -t ext4
#df -t xfs

5. To exculde the particular file type.

Syntax:
df [option] [argument]

Example:
#df -x ext4

6. To show the output in inodes instead of Block size.

Syntax:
df [option]

Example:
#df -i

7. To show the output as a particular field.

Syntax:
df [option]=[field1,field2,field3...]

Example:
#df --output=size,used,avail

8. To check the Block size in KB, MB and GB.

Syntax:
df [option] [argument]

Example:
#df -B k
#df -B m
#df -B g

1. How to check RAM size in kibibytes.

Example:
#free -k

2. How to check RAM size in kilobytes.

Example:
#free --kilo

3. How to check RAM size in mebibytes.

Example:
#free -m

4. How to check RAM size in megabytes.

Example:
#free --mega

5. How to check RAM size in gibibytes.

Example:
#free -g

6. How to check RAM size in gigabytes.

Example:
#free --giga

7. How to check RAM size in human readable format.

Example:
#free -h

8. How to check RAM size in terabytes and petabytes.

Example:
#free --tera  //for terabytes
#free --peta //for petabytes

9. How to check RAM utlization in every seconds

Example:
#free -s

10. How to check RAM utlization in every 5 seconds till 10 count

Example:
#free -s 5 -c 10