[API Proposal]: Expose API for escaping command-line arguments

[Youssef1313]

Background and motivation

The core logic is in an internal PasteArguments.AppendArgument. But it's not exposed directly for users usage.

While ProcessStartInfo today already supports passing a list of unescaped arguments (ArgumentList property), it cannot be used together with Arguments property.

API Proposal

namespace System.Diagnostics;

public class ProcessStartInfo
{
    public static string EscapeArgument(string argument);
}

API Usage

// Fancy the value
var info = new ProcessStartInfo()
{
    FileName = ...;
}

var builder = new StringBuilder();
builder.Append(myAlreadyEscapedArgumentsComingFromElsewhere);
foreach (var arg in listOfUnescapedArguments)
{
    builder.Append(ProcessStartInfo.EscapeArgument(arg));
}
info.Arguments = builder.ToString(); 

Real-world example is SDK:

https://github.com/dotnet/sdk/blob/15c4fb1e5086e8a61876fd60b612a51cac1774c2/src/Cli/dotnet/Commands/Test/TestApplication.cs#L97

There, Module.RunProperties.Arguments is already a single string which can contain multiple arguments like --report-trx --results-directory "Path Containing Spaces" which is already escaped properly.
Then, there are multiple more arguments that need to be constructed and are not escaped.

NOTE: ArgumentEscaper.EscapeSingleArg implementation seems like it's already diverging from the implementation in dotnet/runtime. And somewhere in dotnet/msbuild there is even another implementation somewhere.

Alternative Designs

Allow both ProcessStartInfo.Arguments and ArgumentList to be used together.

Risks

No response

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[MihuBot]

I'm a bot. Here is a possible related and/or duplicate issue (I may be wrong):

• Add ProcessStartInfo.ArgumentList #23347

[adamsitnik]

ArgumentList predates me as an owner of System.Diagnostics.Process, but my understanding is that it was designed as the new, recommended way of passing arguments to a new process. Arguments property was not removed for backward compat reasons.

So instead of:

var builder = new StringBuilder();
builder.Append(myAlreadyEscapedArgumentsComingFromElsewhere);
foreach (var arg in listOfUnescapedArguments)
{
    builder.Append(ProcessStartInfo.EscapeArgument(arg));
}
info.Arguments = builder.ToString(); 

The users can forget about escaping and just provide the args:

foreach (var arg in listOfUnescapedArguments)
{
    info.ArgumentList.Add(arg);
}

And in your case you have some pre-concatenated string with some escaped args and you would like to add some more to it?

[Youssef1313]

And in your case you have some pre-concatenated string with some escaped args and you would like to add some more to it?

Yes. In my case I have already a single string that is properly escaped already. So I think an alternative is to provide an API to "unescape" it, then use ArgumentList?

[adamsitnik]

So I think an alternative is to provide an API to "unescape" it, then use ArgumentList?

System.CommandLine (already used by the SDK) provides an API for that:

https://github.com/dotnet/command-line-api/blob/fab13a397461f4ff16b988ba96cb08891ac75257/src/System.CommandLine/Parsing/CommandLineParser.cs#L40

This test shows how it works: https://github.com/dotnet/command-line-api/blob/fab13a397461f4ff16b988ba96cb08891ac75257/src/System.CommandLine.Tests/SplitCommandLineTests.cs#L36-L41

But back to your original request for now I am hesitant of adding such API. You are the first user asking for it since ArgumentList was added in .NET Core 2.1 (8 years ago?) I would prefer to wait and get more up votes/feedback for a while

[KalleOlaviNiemitalo]

CommandLineParser.SplitCommandLine(string commandLine) matches neither CommandLineToArgvW nor POSIX sh word splitting.

From where do you get the "single string that is properly escaped already": is it built by some API, or read from a file edited by a user?

[Youssef1313]

@KalleOlaviNiemitalo For the case of SDK, that's RunArguments MSBuild property (coming from user)

[jkotas]

Related: #668