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I have a trivial console application in .NET. It's just a test part of a larger application. I'd like to specify the "exit code" of my console application. How do I do this?

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14 Answers 14

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739

Three options:

  • You can return it from Main if you declare your Main method to return int.
  • You can call Environment.Exit(code).
  • You can set the exit code using properties: Environment.ExitCode = -1;. This will be used if nothing else sets the return code or uses one of the other options above).

Depending on your application (console, service, web application, etc.), different methods can be used.

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10 Comments

For those of you who wonder why this does not work in their case, make sure your project is compiled as a "Console application" and not as a "Windows application".
what if I have a WinForms app that with some args I want it to behave as a console app?
You can also just type the maine program as int (replace void by int) and use e.g. "return -1;" to return from the main program. This is more portable than Environment.Exit() (which depends on the environment).
@DannyBeckett By convention, an exit code of 0 means success, and non-zero means failure. return; indicates success through exit code 0, and return -1; indicates failure.
You can also set the exit code using properties: Environment.ExitCode = -1;
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313

In addition to the answers covering the return int's... a plea for sanity. Please, please define your exit codes in an enum, with Flags if appropriate. It makes debugging and maintenance so much easier (and, as a bonus, you can easily print out the exit codes on your help screen - you do have one of those, right?).

enum ExitCode : int {
  Success = 0,
  InvalidLogin = 1,
  InvalidFilename = 2,
  UnknownError = 10
}

int Main(string[] args) {
   return (int)ExitCode.Success;
}
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9 Comments

You might want to add, that the value of "0" for "Success" is not by chance, but actually the "standard" value for that situation.
I'm aware that 0 is standard for sucess. Is there a agreed convention for other exit codes or is it just a free for all? (I presume these are the same numbers you get back after running a scheduled task).
You say that 0 is the standard value for success, and yet when converting 0/1 to boolean, 0 is false and 1 is true! It may be more accurate to say that an exit code of 0 means "no error", rather than "success", as the exit code is an ErrorResult not simply a Result.
For the complete list of microsoft convention, see msdn.microsoft.com/en-us/library/windows/desktop/…. Some guy has made a huge list of consts and used it in a switch case in comments further below.
@MarkShapiro, I guess 0 = Success comes from the fact that there is only one success code needed, but many error codes, such that 0, as having no + or - in Computer integers, can be used to uniquely identify success
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62

There are three methods that you can use to return an exit code from a console application.

  1. Modify the Main method in your application so that it returns an int instead of void (a function that returns an Integer instead of Sub in VB.NET) and then return the exit code from that method.
  2. Set the Environment.ExitCode property to the exit code. Note that method 1. takes precedence - if the Main method returns anything other than void (is a Sub in VB.Net) then the value of this property will be ignored.
  3. Pass the exit code to the Environment.Exit method. This will terminate the process immediately as opposed to the other two methods.

An important standard that should be observed is that 0 represents 'Success'.

On a related topic, consider using an enumeration to define the exit codes that your application is going to return. The FlagsAttribute will allow you to return a combination of codes.

Also, ensure that your application is compiled as a 'Console Application'.

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2 Comments

This brings up an interesting point. Setting Environment.ExitCode doesn't close the program immediately but Environment.Exit method closes the program immediately
Exit code also works on windows applications. If the app would be started from c#, through a Process object, you can ask the object to WaitForExit(), and then request the exit code from it.
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If you are going to use the method suggested by David, you should also take a look at the [Flags] Attribute.

This allows you to do bit wise operations on enums.

[Flags]
enum ExitCodes : int
{
  Success = 0,
  SignToolNotInPath = 1,
  AssemblyDirectoryBad = 2,
  PFXFilePathBad = 4,
  PasswordMissing = 8,
  SignFailed = 16,
  UnknownError = 32
}

Then

(ExitCodes.SignFailed | ExitCodes.UnknownError)

would be 16 + 32. :)

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3 Comments

This implies that a program would say 'your password is wrong' then go on to try and sign whatever it's signing, and only stop if it then fails. You should return once you have failed; anything else is a warning and the program should still return 0.
Little known fact is that [Flags] does nothing to enable or disable bitwise operations. All it does is override the ToString method so that the output represents the bitwise flags. With or without it, you can still do bitwise operations.
@Steven that's nice to know but I'd still recommend decorating enums intended for "flag usage" with that attribute, if nothing else it conveys intention.
30 
System.Environment.ExitCode

See Environment.ExitCode Property.

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29 
int code = 2;
Environment.Exit( code );
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5 Comments

Any technical reason you didn't just write "Environment.Exit( 2 );" ?
Assigning a magic number to a variable with a meaningless name does not make it any less magic.
@Blorgbeard - Seven years has elapsed between your two comments. That's kinda epic. :-D
@Tornseglare I'm looking forward to update on this. Should be coming in a few months :)
@el-ronnoco - are you as disappointed as I am?
17

Just return the appropiate code from main.

int Main(string[] args)
{
    return 0; // Or exit code of your choice
}
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12

Use ExitCode if your main has a void return signature. Otherwise, you need to "set" it by the value you return.

From Environment.ExitCode Property:

If the Main method returns void, you can use this property to set the exit code that will be returned to the calling environment. If Main does not return void, this property is ignored. The initial value of this property is zero.

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10

As an update to Scott Munro's answer:

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4 Comments

Can your 1st point regarding C# 6 be verified? I can't seem to find anything online. The return value from the Main function is attached to the exit code of the process (at least in all the previous compilers), why they should have changed that?
Pure anecdotal evidence, but I just ran into this in my own library, where simply returning my result/error code from Main() didn't set the Process.ExitCode as seen by the calling application.
MSDN contends int Main is still can be used as an alternative to Environment.ExitCode. link
I have an application that runs multiple threads. In certain circumstances, I need to clobber some threads via Thread.Abort(), prior to exiting the application. In these circumstances, int Main(){...thread.Abort(); ... return 0;} does NOT result in a process exit code of 0: the process exit code is -1. It seems in certain circumstances, MS has decided that the convention of using the return value of the main thread to set the exit code of the process, is not good enough for them. In fairness, it might be a timing issue: the thread abort might be setting the exit code very late in the game.
8

The enumeration option is excellent. However, it can be improved upon by multiplying the numbers as in:

enum ExitCodes : int
{
  Success = 0,
  SignToolNotInPath = 1,
  AssemblyDirectoryBad = 2,
  PFXFilePathBad = 4,
  PasswordMissing = 8,
  SignFailed = 16,
  UnknownError = 32
}

In the case of multiple errors, adding the specific error numbers together will give you a unique number that will represent the combination of detected errors.

For example, an errorlevel of 6 can only consist of errors 4 and 2, 12 can only consist of errors 4 and 8, 14 can only consist of 2, 4 and 8 etc.

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1 Comment

That is if you bother to check for further errors after encountering one, though. Most apps don't.
4

You can find the system error codes on System Error Codes (0-499).

You will find the typical codes, like 2 for "file not found" or 5 for "access denied".

And when you stumble upon an unknown code, you can use this command to find out what it means:

net helpmsg decimal_code

For example,

net helpmsg 1

returns

Incorrect function
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3

I'm doing it like this:

int exitCode = 0;
Environment.Exit(exitCode);

Or you can throw an error (personal preference):

throw new ArgumentException("Code 0, Environment Exit");

I've choose ArgumentException, but you can type other. It will work fine.

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3 Comments

That didn't even compile - Environment misspelled as Enviroment.
What will happen when the exception is thrown (presumably not caught anywhere in the console application)? What is the resulting exit code (the question was "How do I specify the exit code of a console application in .NET?")? Can you provide a working example (that actually compiles)? Can you back it up with references to documentation? Please respond by editing (changing) your answer, not here in comments (without "Edit:", "Update:", or similar - the answer should appear as if it was written today).
This question (stackoverflow.com/questions/43195148/…) asks that explicitly and has some interesting discussion and suggestions. It has been observed that exit values on uncaught exceptions vary across OS's, and appear to be consistent within a given OS. But no one has provided a definitive answer.
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Use this code

Environment.Exit(0);

use 0 as the int if you don't want to return anything.

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2 Comments

This isn't answering OP's question and returning 0 is returning something...
it's returning what an app normally returns. If you don't specify it, an app return 0
-3

Just another way:

public static class ApplicationExitCodes
{
    public static readonly int Failure = 1;
    public static readonly int Success = 0;
}
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1 Comment

How does that answer the question? Is it a response to another answer, like Mark Brackett's answer?

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