Remove all blank lines from a file

[Rene Zwanenburg via Digitalmars-d-learn]

On Thursday, 31 August 2017 at 14:44:07 UTC, vino wrote:
> Hi All,
>
>   Can some provide me a example of how to remove all blank 
> lines from a file.
>
> From,
> Vino.B

This one doesn't read the entire file into memory:

import std.stdio;
import std.array;
import std.algorithm;
import std.uni;

void main(string[] args)
{
	auto inputFile = File(args[1]);
	auto outputFile = File(args[2], "wb");
	
	inputFile
		.byLine
		.filter!(line => !line.all!isWhite)
		.copy(outputFile.lockingTextWriter);
}

But if you want to replace the input file, you'd have to write to 
a temp file, remove the original, then move the temp file.