get/split substring using bash
get year of a string date
cut -c1-4 <<<'2018/05/30'
get month of a string date
cut -c6-7 <<<'2018/05/30'
get day of a string date
cut -c9-10 <<<'2018/05/30'
get/split substring using awk
using substr function
get year of a string date
awk '{ print substr($0,1,4) }' <<<'2018/05/30'
get month of a string date
awk '{ print substr($0,6,2) }' <<<'2018/05/30'
get day of a string date
awk '{ print substr($0,9) }' <<<'2018/05/30'
using split function
get year of a string date
awk 'split($0,arr,"/") { print arr[1] }' <<<'2018/05/30'
get month of a string date
awk 'split($0,arr,"/") { print arr[2] }' <<<'2018/05/30'
get day of a string date
awk 'split($0,arr,"/") { print arr[3] }' <<<'2018/05/30'