HackerRank

		Linux Shell
		Arrays
Concatenate an Array with itself	Count the Number of Elements in an Array	Display an Element of an Array	Filter an Array with Patterns	Lonely Integer Bash
Read in an Array	Remove the First Capital Letter from each Element	Slice an Array
		BASH
A Personalized Echo	Arithmetic Operations	Comparing Numbers	Compute the Average	Getting Started with Conditionals
Looping and Skipping	Looping with Numbers	More on Conditionals	The World of Numbers
		Grep Sed Awk
Awk 1	Awk 2	Awk 3	Awk 4	Grep 1
Grep 2	Grep 3	Grep A	Grep B	Sed 1
Sed 2	Sed 3	Sed 4	Sed 5
		Text Processing
Cut 1	Cut 2	Cut 3	Cut 4	Cut 5
Cut 6	Cut 7	Cut 8	Cut 9	Head of a Text File 1
Head of a Text File 2	Middle of a Text File	Paste 1	Paste 2	Paste 3
Paste 4	Sort 1	Sort 2	Sort 3	Sort 4
Sort 5	Sort 6	Sort 7	Tail of a Text File 1	Tail of a Text File 2
Tr 1	Tr 2	Tr 3	Uniq 1	Uniq 2
Uniq 3	Uniq 4

		SQL
		Aggregation
Average Population	Japan Population	Population Density Difference	Revising Aggregations Averages	The Blunder
		Basic Select
Employee Names	Employee Salaries	Higher than 75 Marks	Japanese Cities Attributes	Japanese Cities Names
Revising the Select Query 1	Revising the Select Query 2	Select All	Select by ID	Weather Observation Station 1
Weather Observation Station 3	Weather Observation Station 4	Weather Observation Station 5	Weather Observation Station 6	Weather Observation Station 7
Weather Observation Station 8	Weather Observation Station 9	Weather Observation Station 10	Weather Observation Station 11	Weather Observation Station 12