Getting Return Values from Piping Executables with Windows Tech Support
In this article, we will cover how to run unit tests that involve piping executables in Windows, and how to get the return values of those executables. We will discuss the following key concepts:
- Piping executables in Windows
- Running commands and getting return values
- Unit testing with piped executables
Piping Executables in Windows
Piping is a powerful feature in Windows that allows you to chain together multiple commands, sending the output of one command as input to the next. This can be done using the vertical bar character (|). For example, the following command will send the contents of the file text.txt as input to the my_exe executable:
cat text.txt | my_exeRunning Commands and Getting Return Values
When running an executable in Windows, it is often useful to get the return value of the command. This can be done using the ErrorLevel variable. For example, the following command will run the my_exe executable and store the return value in the ErrorLevel variable:
my_exe > nul && echo The command succeeded. || echo The command failed.Unit Testing with Piped Executables
Unit testing is an important part of any software development process. When working with piped executables, it is important to be able to write unit tests that can handle the input and output of these commands. One way to do this is to use a testing framework such as MSTest or NUnit. These frameworks allow you to write tests that can run the command, capture the output, and verify the return value.
Example
Here is an example of how you might write a unit test for a piped executable:
[TestMethod]
public void TestPipedExecutable()
{
// Arrange
string input = "Hello, World!";
string expectedOutput = "HELLO, WORLD!";
string command = $"echo {input} | tr '[:lower:]' '[:upper:]'";
// Act
string output = RunCommand(command);
// Assert
Assert.AreEqual(expectedOutput, output);
}
private string RunCommand(string command)
{
// Create a new process
Process process = new Process();
// Set the start info
process.StartInfo.FileName = "cmd.exe";
process.StartInfo.Arguments = $"/c {command}";
process.StartInfo.RedirectStandardOutput = true;
process.StartInfo.UseShellExecute = false;
// Start the process
process.Start();
// Read the output
string output = process.StandardOutput.ReadToEnd();
// Wait for the process to exit
process.WaitForExit();
// Return the output
return output;
}References
This article was written using the following resources:
- Microsoft Docs: docs.microsoft.com
- MSTest: mstest command-line options
- NUnit: nunit.org