Create File Of Any Size

The below command will create a file with name "geek.txt"

dd if=/dev/zero of=geek.txt bs=1024 count=0 seek=1024

Example:

Create a file of 10M:
dd if=/dev/zero of=geek.txt  bs=10M  count=1

Create a file of 100M:
dd if=/dev/zero of=geek.txt  bs=100M  count=1

Create a file of 1G:
dd if=/dev/zero of=geek.txt  bs=1024M  count=1

Create a file of 2G:
dd if=/dev/zero of=geek.txt  bs=2048M  count=1

create a file of 10G: 
dd if=/dev/zero of=geek.txt  bs=1024M  count=10