Parse json string provided as Process Start Info Arguments for exe C#

Question

Hi I have an application which i need to execute from another exe. The same json string works fine when i pass as command line arguments; but fails when i pass it as Process Start Info Arguments.

command line arguments:

Input (i.e. args[0]): "{\"mydllpath\":\"D:\\dll\",\"FilePath\":\"D:\\Input\\abc.doc\", \"Attribute\":\"word\"}"

Console.Writeline: {"mydllpath":"D:\\dll","FilePath":"D:\\Input\\abc.doc", "Attribute":"word"}

Success parsing

Process Start Info Arguments:

Input: "{\"mydllpath\":\"D:\\dll\",\"FilePath\":\"D:\\Input\\abc.doc\", \"Attribute\":\"word\"}"

Console.Writeline:{"mydllpath":"D:\dll","FilePath":"D:\Input\abc.doc", "Attribute":"word"}

Failed parsing: Unexpected character encountered while parsing value: D.

ProcessStartInfo psi = new ProcessStartInfo("D:\\ETS\\AE\\bin\\Debug\\AE.exe");
string json = "{\"mydllpath\":\"D:\\dll\",\"FilePath\":\"D:\\Input\\abc.doc\", \"Attribute\":\"word\"}";
psi.Arguments = json;
Process p = new Process();
Debug.WriteLine(psi.FileName + " " + psi.Arguments);
p.Start();
p.StartInfo = psi;

Brocket

Include the code used to make the process call. – Avelar

For clarification, the above JSON in the code, why are you escaping the slashes in the paths? – Avelar

It gives error without the escape sequence – Brocket

Answer 1

You need to wrap the argument with "", and escape '"' symbol by replacing it with '""'.

Here is a sample code to start the application with the JSON command line argument

    var argumentString = JsonSerializer.Serialize(new
    {
        DeviceId = _deviceInfo?.DeviceId,
        ApplicationStartUrl = _deviceInfo?.AppStartUrl
    }).Replace("\"", "\"\"");
    argumentString = $"\"{argumentString}\""; 
 
    var processStartupInfo = new ProcessStartInfo(Path.Combine("Application",
_configuration.Executable ?? ""), argumentString);
    processStartupInfo.WorkingDirectory = Path.Combine(Assembly.GetExecutingAssembly().Location, "Application");
    _applicationProcess = Process.Start(processStartupInfo);

Photic

Answer 2

The passed arguments is not being escaped properly

it should be properly escaped

var jsonString = "{\"mydllpath\":\"D:\dll\",\"FilePath\":\"D:\Input\abc.doc\", \"Attribute\":\"word\"}";
var args = string.Format("\"\"\"{0}\"\"\"", jsonString);
psi.Arguments = args;
//...

Reference ProcessStartInfo.Arguments Property

Avelar

Error!! "Bad JSON escape sequence" – Brocket

@Brocket alright I'll remove my comments and update answer so you can see what I mean. – Avelar

It still gives error "unrecognized escape sequence" in VS editor – Brocket

@Brocket are you referring to runtime error or syntax error when you refer to VS editor error? That shoulds more like a syntax error – Avelar

@Brocket take a look at the following docs learn.microsoft.com/en-us/dotnet/api/… – Avelar

Answer 3

so many years no answer... I encounter the problem and finally got is work with a tricky way, it's a node process in my case. Hope it can help.

1. Replace " to single quote ' in the parameter in .net side (because process argument will take " as no quote, so your process will receive a json string without quote!!!)

   argumentStr= argumentStr.Replace(""", "'"); proc.StartInfo.Arguments = $"app.js "{argumentStr}""

2. Replace ' with " in node side

   let arg= process.argv[2]; arg = arg.replace(/'/g, '"'); const yourObject = JSON.parse(arg);

Gregson

Answer 4

Only thing that worked for me was to convert to base64, and then convert back afterwards

string args = Convert.ToBase64String(Encoding.UTF8.GetBytes(JsonConvert.SerializeObject(request)));

            using (Process process = new Process())
            {
               process.StartInfo = new ProcessStartInfo()
               {
                  FileName = Assembly.GetExecutingAssembly().Location,
                  Arguments = args,
                  UseShellExecute = false,
                  CreateNoWindow = true
               };

               process.Start();
               process.WaitForExit(timeoutSeconds * 1000);
            }

byte[] bytes = Convert.FromBase64String(args);
         string requestStr = System.Text.Encoding.UTF8.GetString(bytes);
         ReportRequest request = JsonConvert.DeserializeObject<ReportRequest>(requestStr);

Narah