Running a command in a command line tool in fastest way

Question

Before anything I want to clarify some terms : 
apk
file (android application package file) : equivalent to executable (exe) files on windows
aapt.exe
: A command line tool which comes with android sdk in order to fetch information of an apk file (It obviously has other usages)
note : This question is not about an android feature. It's all about C# and functionality of .Net framework 
An
apk file has a name just same as any other file, but it has a internal name (which will be shown when you install apk file on android os as name of application) 
with
aapt.exe I can get internal name of an apk using following command :  
aapt
d badging "<apk path>"
I
have copied aapt.exe where executable file of my c# application is and I want  :
Enter
above command for each apk in selected directory (using GetAllFiles method)
I want to get internal names of apk files and
I've tried a lot of ways and I've searched a lot. finally this is what I've got : 
Process proc = new Process();
proc.StartInfo.FileName = "cmd.exe";
proc.StartInfo.RedirectStandardInput = true;
proc.StartInfo.RedirectStandardOutput = true;
proc.StartInfo.UseShellExecute = false;
proc.StartInfo.StandardOutputEncoding = System.Text.Encoding.UTF8;
proc.Start();
using (StreamWriter sw = proc.StandardInput)
foreach (string path in Directories.GetAllFiles(@"E:\apk", "apk"))
sw.WriteLine("aapt d badging " + "\"" + path + "\"");
//following line doesn't work because sStandardInput is open
Debug.WriteLine(proc.StandardOutput.ReadToEnd());
// There will be a really huge amount of text (at least 20 line per sw.Writeline) and
//it impacts performance so following line is not really what I'm looking for
Debug.WriteLine(proc.StandardOutput.ReadToEnd());
GetAllFiles is
a function that I've created to fetch all apk file full path. It gets two argument. First argument is path and second one is extension of file you want its full path to be fetched.
This is not final code.
As I've commented it out first Debug.WriteLine doesn't
work and second one is not a good idea. how should I get output from proc?
I have tried running process by argument and its awful :)
As another approach :
Because apk files are basically zip files I can extract them get what I want from them.
There is an xml file named Androidmanifest.xml in every apk file.
Androidmanifest.xml is like an ID card for an apk file and apk internal name can be found in it but here are some problems with this approach : 
1. Androidmanifest.xml is not a plain text file. It's coded and it requires a lot of complexity to decode it
2. application name (or apk internal name) is an attribute in this file and it's value is not a string value. It's a reference to a file where strings are stored and worst thing is it's not an easy to find out reference. It's just a number

Answer 1

And you don't get any output from it? Maybe you're passing the arguments incorrectly?
No. I don't get any result and I have checked arguments and it's correct.
But you are already running a separate process for every apk file. You start a single cmd.exe and then send it commands that will cause aapt to be run for every file. Unless aapt accepts multiple apk filenames on the command line there's no way
around using separate processes.
I didn't know that. anyway speed in this way is much more rather than creating a function. creating a Process object in it and calling function for each apk file.
I read somewhere that it's possible to run multiple commands in cmd by & operator but as you said I think every command runs aapt. I have tested this approach too and it's very very slow
fastest approach I have found is what I have wrote here and speed is about  0.6 per apk file which is still slow when there is thousands of apk files.
I tried an application that does same thing (fetching apk information) and in it's installation directory I found aapt.exe which means it uses this tool to get information but speed is significantly faster rather than my application.   
So what's your suggestion about this?