added file merge functionality

README.md

@@ -11,6 +11,17 @@ A no-nonsense, user-extensible `fortune-mod` replacement.
 This project was originally built in Rust, and I migrated it to C# primarily to
 test out [bflat](https://github.com/bflattened/bflat).
 
+<details>
+<summary><h2>Methodology</h2></summary>
+
+`fortune-cs` starts by selecting a category file, then a line, so the user will
+see a normal representation of each file. Then, it selects a line from the file.
+
+The fortune files themselves can be extended just by appending;
+`cat b.txt >> a.txt` is a perfectly valid way of merging two files.
+
+</details>
+
 ## Installation
 
 ### Application

src/Program.cs

@@ -2,6 +2,12 @@ using System;
 using System.IO;
 using System.Security.Cryptography;
 
+//	use merge function if given multiple arguments
+if(args.Length > 0) {
+	Utilities.Merge(args);
+	return 0;
+}
+
 //	make sure fortune directory exists
 var resourcePath = "/usr/share/fortune-cs/";
 if(!Directory.Exists(resourcePath)) {
@@ -12,15 +18,11 @@ if(!Directory.Exists(resourcePath)) {
 //	pull file list
 var files = Directory.GetFiles(resourcePath, "*.txt");
 
-var prng = RandomNumberGenerator.Create();
-
 //	choose a file and line
 var file = files[RandomNumberGenerator.GetInt32(files.Length)];
 var lines = File.ReadAllLines(file);
 var line = lines[RandomNumberGenerator.GetInt32(lines.Length)];
 
-prng.Dispose();
-
 //	process escape codes
 line = line.Replace("\\n", "\n");
 

src/Util.cs

@@ -0,0 +1,29 @@
+using System;
+using System.Collections.Generic;
+using System.IO;
+
+public static class Utilities {
+
+	public static void Merge(params string[] files) {
+		//	hashset to prevent duplicates
+		var members = new HashSet<string>();
+		//	iterate over all paths given
+		foreach(var file in files) {
+			//	skip nonexistent files gracefully
+			if(!File.Exists(file))
+				continue;
+			//	iterate over lines
+			var lines = File.ReadAllLines(file);
+			foreach(var line in lines) {
+				//	prevent duplicates
+				if(members.Contains(line))
+					continue;
+				members.Add(line);
+				//	emit to stdout
+				Console.WriteLine(line);
+			}
+		}
+	}
+
+}
+