What is the purpose of the END block?

The END block in awk is used to specify actions that should be performed after all input lines have been processed. It allows you to execute commands or calculations that depend on the entire dataset rather than individual lines.

Key Purposes of the END Block:

1. Final Calculations: You can perform calculations that require knowledge of all input data, such as averages, totals, or summaries.

2. Output Summary: It is often used to print summary information or results after processing all lines, such as printing a final count or aggregated results.

3. Cleanup Actions: You can use it for any cleanup actions or final adjustments that need to be made after processing the input.

Example:

Here’s a simple example to illustrate its use:

awk '{sum += $1} END {print "Total:", sum}' numbers.txt

In this example:

• The first part {sum += $1} accumulates the sum of the first field for each line.
• The END block {print "Total:", sum} is executed after all lines have been processed, printing the total sum.

Without the END block, you would not be able to output the total after processing all lines, as the output would be generated for each line instead.