SimpleExec

SimpleExec is a .NET library that runs external commands. It wraps System.Diagnostics.Process to make things easier.

SimpleExec intentionally does not invoke the system shell.

By default, the command is echoed to standard error (stderr) for visibility.

Platform support: .NET Standard 2.1 and later.

Quick start

using static SimpleExec.Command;

Run("foo.exe", "arg1 arg2");

API

Run

Run("foo.exe");
Run("foo.exe", "arg1 arg2", "my-working-directory");

await RunAsync("foo.exe");
await RunAsync("foo.exe", "arg1 arg2", "my-working-directory");

Read

var (standardOutput1, standardError1) = await ReadAsync("foo.exe");
var (standardOutput2, standardError2) = await ReadAsync("foo.exe", "arg1 arg2", "my-working-directory");

Other optional arguments

bool noEcho = false,
string? windowsName = null,
string? windowsArgs = null,
string? echoPrefix = null,
Action<IDictionary<string, string>>? configureEnvironment = null,
bool createNoWindow = false,
Func<int, bool>? handleExitCode = null,
CancellationToken cancellationToken = default,

Exceptions

If the command has a non-zero exit code, an ExitCodeException is thrown with an int ExitCode property and a message in the form of:

$"The process exited with code {ExitCode}."

In the case of ReadAsync, an ExitCodeReadException is thrown, which inherits from ExitCodeException, and has string Out and Error properties, representing standard out (stdout) and standard error (stderr), and a message in the form of:

$@"The process exited with code {ExitCode}.

Standard Output:

{Out}

Standard Error:

{Error}"

Overriding default exit code handling

The throwing of exceptions for specific non-zero exit codes can be suppressed by passing a delegate to handleExitCode which returns true when it has handled the exit code and default exit code handling should be suppressed, and returns false otherwise. For example:

Run("ROBOCOPY", "from to", handleExitCode: code => code < 8);

Note that it may be useful to record the exit code. For example:

var exitCode = 0;
var result = Run("ROBOCOPY", "from to", handleExitCode: code => (exitCode = code) < 8);

// see https://ss64.com/nt/robocopy-exit.html
var oneOrMoreFilesCopied = exitCode & 1;
var extraFilesOrDirectoriesDetected = exitCode & 2;
var misMatchedFilesOrDirectoriesDetected = exitCode & 4;

Windows

🙄

Sometimes, for whatever wonderful reasons, it's necessary to run a different command on Windows. For example, when running Yarn, some combination of mysterious factors may require that you explicitly run cmd.exe with Yarn as an argument, rather than running Yarn directly. The optional windowsNames and windowsArgs parameters may be used to specify a different command name and arguments for Windows:

Run("yarn", windowsName: "cmd", windowsArgs: "/c yarn");

_{Run by Gregor Cresnar from the Noun Project.}

lebiru/simple-exec