diff --git a/packages/ash/assembly/__tests__/error.spec.ts b/packages/ash/assembly/__tests__/error.spec.ts
new file mode 100644
index 0000000..e7fc38d
--- /dev/null
+++ b/packages/ash/assembly/__tests__/error.spec.ts
@@ -0,0 +1,42 @@
+import { stdout, Hello, World, readString, stderr } from './fixtures';
+import { main as error } from "../bin/error";
+import { main as cat } from "../bin/cat";
+import { main as echo } from "../bin/echo";
+
+
+describe("error", (): void => {
+
+  beforeEach((): void => {
+    stdout.reset();
+    Console.stdout.erase();
+    CommandLine.reset();
+
+  })
+
+  it("cat should cause an error if the file doesn't exist", (): void => {
+    CommandLine.push("cat");
+    CommandLine.push("thisshouldn'twork");
+    cat(CommandLine.all());
+
+    let status = error();
+
+    expect<i32>(status).toBe(1);
+
+
+
+
+  });
+
+  it("echo should not cause any error", (): void => {
+    CommandLine.push("echo");
+    CommandLine.push("test");
+    echo(CommandLine.all());
+
+    let status = error();
+
+    expect<i32>(status).toBe(0);
+
+
+  });
+
+})
diff --git a/packages/ash/assembly/bin/cat.ts b/packages/ash/assembly/bin/cat.ts
index 9701571..e3dff3f 100644
--- a/packages/ash/assembly/bin/cat.ts
+++ b/packages/ash/assembly/bin/cat.ts
@@ -4,8 +4,10 @@ export function main(args: string[]): void {
     if (args.length > 1) {
         for (let i: i32 = 1; i < args.length; i++) {
             let file = fs.openFile(args[i]);
+
             if (file.failed) {
                 Console.error("cat: " + args[i] + ": No such file or directory");
+                Process.error(44);
                 continue;
             }
             Console.log(file.result.readString().result);
diff --git a/packages/ash/assembly/bin/error.ts b/packages/ash/assembly/bin/error.ts
new file mode 100644
index 0000000..da61157
--- /dev/null
+++ b/packages/ash/assembly/bin/error.ts
@@ -0,0 +1,12 @@
+
+export function main(): i32 {
+    let code = Process.error_flag;
+    if (code != 0) {
+        Process.error_flag = 0;
+        return 1;
+    }
+    else {
+
+        return 0;
+    }
+}
diff --git a/packages/assemblyscript/assembly/wasa/mock/process.ts b/packages/assemblyscript/assembly/wasa/mock/process.ts
index fc3382c..7697f08 100644
--- a/packages/assemblyscript/assembly/wasa/mock/process.ts
+++ b/packages/assemblyscript/assembly/wasa/mock/process.ts
@@ -6,11 +6,17 @@ import { Wasi } from "../../wasi";
 export class Process {
     static _singleton: Process;
 
+    // Error status flag 
+    public static error_flag: i32;
+
     constructor(cwd: fd) {
         this._cwd = cwd;
+        Process.error_flag = 0;
         Process._singleton = this;
+
     }
     _cwd: fd;
+
     /**
      * Cleanly terminate the current process
      * @param status exit code
@@ -22,6 +28,18 @@ export class Process {
         abort();
     }
 
+    /**
+     * Set Process error flag without aborting
+     * @param status exit code
+     */
+    static error(status: i32): void {
+        Process.error_flag = status;
+    }
+
+
+
+
+
     static get cwd(): fd {
         return Process._singleton._cwd;
     }
diff --git a/types/wasa/index.d.ts b/types/wasa/index.d.ts
index a65d5e2..5fd696d 100644
--- a/types/wasa/index.d.ts
+++ b/types/wasa/index.d.ts
@@ -354,6 +354,7 @@ declare class DirectoryEntry {
  */
 declare class Process {
   static exit(code: number): void;
+  static error(code: number): void;
 }