diff --git a/packages/ash/assembly/__tests__/nl.spec.ts b/packages/ash/assembly/__tests__/nl.spec.ts
new file mode 100644
index 0000000..289bde0
--- /dev/null
+++ b/packages/ash/assembly/__tests__/nl.spec.ts
@@ -0,0 +1,64 @@
+import { main as nl } from "../bin/nl";
+import { stdout, stderr } from './fixtures';
+
+
+describe("nl", (): void => {
+    beforeEach((): void => {
+        stdout.reset()
+        Console.stdout.erase() //Erases and resets
+        stderr.reset();
+        Console.stderr.erase() //Erases and resets
+        CommandLine.reset();
+        CommandLine.push("nl");
+    });
+
+    it("with numbers", (): void => {
+        CommandLine.push("/numbers")//See ./simple_fs.ts
+        nl(CommandLine.all())
+        let str = "    1  0\n    2  1\n    3  2\n    4  3\n    5  4\n    6  5\n" +
+            "    7  6\n    8  7\n    9  8\n    10  9\n    11  10\n    12  11\n    13  12\n" +
+            "    14  13\n    15  14\n    16  15\n    17  16\n    18  17\n    19  18\n    20  19\n";
+        stdout.reset();
+        expect<u32>(Console.stdout.tell()).toBe(str.lengthUTF8 - 1, "FD offset should be length of string");
+        expect<string>(stdout.readString().result).toStrictEqual(str);
+    });
+
+    it("with words", () => {
+        CommandLine.push("/home/bob/documents/secret.txt");
+        let str = "    1  For my eyes only.\n    2   No one else"
+        nl(CommandLine.all());
+        stdout.reset();
+        expect<string>(stdout.readString().result).toStrictEqual(str);
+        expect<u32>(Console.stdout.tell()).toBe(str.lengthUTF8 - 1, "FD offset should be length of string");
+    })
+
+    it("should write to stderr if file not found", () => {
+        CommandLine.push("/doesnotexist");
+        nl(CommandLine.all())
+        expect<usize>(Console.stderr.tell()).toBeGreaterThan(0);
+        expect<string>(stderr.readString().result).toStrictEqual("nl: /doesnotexist: No such file or directory\n")
+    });
+
+    it("options - t", () => {
+        CommandLine.push("-b")
+        CommandLine.push("t")
+        CommandLine.push("/home/bob/documents/secret.txt");
+        let str = "    1  For my eyes only.\n    2   No one else"
+        nl(CommandLine.all());
+        stdout.reset();
+        expect<string>(stdout.readString().result).toStrictEqual(str);
+        expect<u32>(Console.stdout.tell()).toBe(str.lengthUTF8 - 1, "FD offset should be length of string");
+    })
+
+    it("options - n", () => {
+        CommandLine.push("-b")
+        CommandLine.push("n")
+        CommandLine.push("/home/bob/documents/secret.txt")
+        nl(CommandLine.all())
+        stdout.reset()
+        let str = "       For my eyes only.\n        No one else"
+        expect<string>(stdout.readString().result).toStrictEqual(str);
+        expect<u32>(Console.stdout.tell()).toBe(str.lengthUTF8 - 1, "FD offset should be length of string");
+    })
+
+})
\ No newline at end of file
diff --git a/packages/ash/assembly/__tests__/simple_fs.ts b/packages/ash/assembly/__tests__/simple_fs.ts
index 22a9ede..6077f25 100644
--- a/packages/ash/assembly/__tests__/simple_fs.ts
+++ b/packages/ash/assembly/__tests__/simple_fs.ts
@@ -16,6 +16,7 @@ export const fs_str = `\
             }\
         }\
     },\
-    "numbers": "0\\n1\\n2\\n3\\n4\\n5\\n6\\n7\\n8\\n9\\n10\\n11\\n12\\n13\\n14\\n15\\n16\\n17\\n18\\n19\\n"\
+    "numbers": "0\\n1\\n2\\n3\\n4\\n5\\n6\\n7\\n8\\n9\\n10\\n11\\n12\\n13\\n14\\n15\\n16\\n17\\n18\\n19\\n",\
+    "newLines": "hey\\n\\nhey"\
 }\
 `
\ No newline at end of file
diff --git a/packages/ash/assembly/bin/nl.ts b/packages/ash/assembly/bin/nl.ts
new file mode 100644
index 0000000..3dd82dc
--- /dev/null
+++ b/packages/ash/assembly/bin/nl.ts
@@ -0,0 +1,36 @@
+export function main(args: string[]): void {
+    let option: string = "";
+    let argnumber = 1;
+    if (args[1] == "-b") {
+        option = args[2]
+        argnumber = 3;
+    }
+    let res = fs.openFile(args[argnumber])
+    if (res.error) {
+        //This is just the log for testing need to use Console.error
+        Console.error("nl: " + args[argnumber] + ": No such file or directory");
+        // log<string>(`head: file: No such file or directory`);
+        return;
+    }
+    let file = res.result;
+    let line = file.readLine();
+    let num = 1;
+    Console.stdin.reset();
+    if (line.failed) {
+        return;
+    }
+
+    while (!line.failed) {
+        let intro = "";
+        if (option == "" || option == "t") {
+            //@ts-ignore  Integer does have to string method.
+            intro = "    " + num.toString() + "  ";
+        }
+        else if (option == "n") {
+            intro = "       "
+        }
+        Console.write(intro.concat(line.result));
+        line = file.readLine();
+        num++;
+    }
+}
diff --git a/packages/assemblyscript/assembly/wasa/mock/utils/index.ts b/packages/assemblyscript/assembly/wasa/mock/utils/index.ts
index 30cd3aa..6aed5d5 100644
--- a/packages/assemblyscript/assembly/wasa/mock/utils/index.ts
+++ b/packages/assemblyscript/assembly/wasa/mock/utils/index.ts
@@ -28,14 +28,13 @@ export class StringUtils {
     static fromCStringTilNewLine(cstring: usize, max: usize): string | null {
         let size: usize = 0;
         while (!this.terminates(cstring + size) && size < max - 1) {
-            if (this.isNewLine(cstring + size)) {
+            if (this.isNewLine(cstring + size++)) {
                 break;
             }
-            size++;
         }
         if (size == 0) {
             return null
         }
-        return String.fromUTF8(cstring, size + 1);
+        return String.fromUTF8(cstring, size);
     }
 }
\ No newline at end of file