How To Execute command line in C get STD OUT results

Question

How do I execute a command-line program from C  and get back the STD OUT results  Specifically  I want to execute DIFF on two files that are programmatically selected and write the results to a text box

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One-liner run command   new Process     StartInfo   new ProcessStartInfo  echo    Hello  World     Start      Read output of command in shortest amount of reable code       var cliProcess   new Process             StartInfo   new ProcessStartInfo  echo    Hello  World                 UseShellExecute   false              RedirectStandardOutput   true                      cliProcess Start        string cliOut   cliProcess StandardOutput ReadToEnd        cliProcess WaitForExit        cliProcess Close

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Start the child process   Process p   new Process        Redirect the output stream of the child process   p StartInfo UseShellExecute   false   p StartInfo RedirectStandardOutput   true   p StartInfo FileName    YOURBATCHFILE bat    p Start        Do not wait for the child process to exit before     reading to the end of its redirected stream      p WaitForExit        Read the output stream first and then wait   string output   p StandardOutput ReadToEnd     p WaitForExit      Code is from MSDN

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Julian s solution is tested working with some minor corrections  The following is an example that also used https   sourceforge net projects bat-to-exe  GenericConsole cs and https   www codeproject com Articles 19225 Bat-file-compiler program txt for args part  using System  using System Text     StringBuilder using System Diagnostics  using System IO    class Program       private static bool redirectStandardOutput   true       private static string buildargument string   args                StringBuilder arg   new StringBuilder            for  int i   0  i  lt  args Length  i                          arg Append  quot   quot  quot    args i     quot   quot   quot                       return arg ToString               static void Main string   args                Process prc   new Process            prc StartInfo     new ProcessStartInfo  quot cmd exe quot   String Format  quot  c   quot   quot  0   quot   1  quot   Path Combine Environment CurrentDirectory   quot mapTargetIDToTargetNameA3 bat quot    buildargument args               new ProcessStartInfo Path Combine Environment CurrentDirectory   quot mapTargetIDToTargetNameA3 bat quot    buildargument args            new ProcessStartInfo  quot mapTargetIDToTargetNameA3 bat quot            prc StartInfo Arguments   buildargument args            prc EnableRaisingEvents   true           if  redirectStandardOutput    true                        prc StartInfo UseShellExecute   false                    else                       prc StartInfo UseShellExecute   true                     prc StartInfo CreateNoWindow   true           prc OutputDataReceived    OnOutputDataRecived          prc ErrorDataReceived    OnErrorDataReceived            prc Exited    OnExited           prc StartInfo RedirectStandardOutput   redirectStandardOutput          prc StartInfo RedirectStandardError   redirectStandardOutput           try                       prc Start                prc BeginOutputReadLine                prc BeginErrorReadLine                prc WaitForExit                      catch  Exception e                        Console WriteLine  quot OS error   quot    e Message                      prc Close                  Handle the dataevent     private static void OnOutputDataRecived object sender  DataReceivedEventArgs e                  do something with your data         Console WriteLine e Data                Handle the error     private static void OnErrorDataReceived object sender  DataReceivedEventArgs e                Console WriteLine e Data                 Handle Exited event and display process information        private static void OnExited object sender  System EventArgs e                    var process   sender as Process            if  process    null                            Console WriteLine  quot ExitCode   quot    process ExitCode                         else                           Console WriteLine  quot Process exited quot                           The code need to compile inside VS2007  using commandline csc exe generated executable will not show console output correctly  or even crash with CLR20r3 error  Comment out the OnExited event process  the console output of the bat to exe will be more like the original bat console output

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Just for fun  here s my completed solution for getting PYTHON output - under a button click - with error reporting  Just add a button called  butPython  and a label called  llHello          private void butPython object sender  EventArgs e                llHello Text    Calling Python              this Refresh            Tuple lt String String gt  python   GoPython   C  Users BLAH Desktop Code Python BLAH py            llHello Text   python Item1     Show result          if  python Item2 Length  gt  0  MessageBox Show  Sorry  there was an error     Environment NewLine   python Item2              public Tuple lt String String gt  GoPython string pythonFile  string moreArgs                     ProcessStartInfo PSI   new ProcessStartInfo            PSI FileName    py exe           PSI Arguments   string Format     0     1    pythonFile  moreArgs           PSI CreateNoWindow   true          PSI UseShellExecute   false          PSI RedirectStandardError   true          PSI RedirectStandardOutput   true          using  Process process   Process Start PSI               using  StreamReader reader   process StandardOutput                                string stderr   process StandardError ReadToEnd       Error s                    string result   reader ReadToEnd       What we want                  return new Tuple lt String String gt   result stderr

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Here s a quick sample     Create process System Diagnostics Process pProcess   new System Diagnostics Process       strCommand is path and file name of command to run pProcess StartInfo FileName   strCommand     strCommandParameters are parameters to pass to program pProcess StartInfo Arguments   strCommandParameters   pProcess StartInfo UseShellExecute   false     Set output of program to be written to process output stream pProcess StartInfo RedirectStandardOutput   true        Optional pProcess StartInfo WorkingDirectory   strWorkingDirectory     Start the process pProcess Start       Get program output string strOutput   pProcess StandardOutput ReadToEnd       Wait for process to finish pProcess WaitForExit

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Start the child process   Process p   new Process        Redirect the output stream of the child process   p StartInfo UseShellExecute   false   p StartInfo RedirectStandardOutput   true   p StartInfo FileName    YOURBATCHFILE bat    p Start        Do not wait for the child process to exit before     reading to the end of its redirected stream      p WaitForExit        Read the output stream first and then wait   string output   p StandardOutput ReadToEnd     p WaitForExit      Code is from MSDN

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You will need to use ProcessStartInfo with RedirectStandardOutput enabled - then you can read the output stream  You might find it easier to use   gt   to redirect the output to a file  via the OS   and then simply read the file    edit  like what Ray did   1

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If you don t mind introducing a dependency  CliWrap can simplify this for you  using CliWrap  using CliWrap Buffered   var result   await Cli Wrap  quot target exe quot       WithArguments  quot arguments quot       ExecuteBufferedAsync     var stdout   result StandardOutput

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This may not be the best easiest way  but may be an option   When you execute from your code  add     output txt  and then read in the output txt file

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If you don t mind introducing a dependency  CliWrap can simplify this for you  using CliWrap  using CliWrap Buffered   var result   await Cli Wrap  quot target exe quot       WithArguments  quot arguments quot       ExecuteBufferedAsync     var stdout   result StandardOutput

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Here s a quick sample     Create process System Diagnostics Process pProcess   new System Diagnostics Process       strCommand is path and file name of command to run pProcess StartInfo FileName   strCommand     strCommandParameters are parameters to pass to program pProcess StartInfo Arguments   strCommandParameters   pProcess StartInfo UseShellExecute   false     Set output of program to be written to process output stream pProcess StartInfo RedirectStandardOutput   true        Optional pProcess StartInfo WorkingDirectory   strWorkingDirectory     Start the process pProcess Start       Get program output string strOutput   pProcess StandardOutput ReadToEnd       Wait for process to finish pProcess WaitForExit

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System Diagnostics ProcessStartInfo psi      new System Diagnostics ProcessStartInfo   program to call exe     psi RedirectStandardOutput   true   psi WindowStyle   System Diagnostics ProcessWindowStyle Hidden   psi UseShellExecute   false   System Diagnostics Process proc   System Diagnostics Process Start psi         System IO StreamReader myOutput   proc StandardOutput   proc WaitForExit 2000    if  proc HasExited            string output   myOutput ReadToEnd

User · Answer

You can launch any command line program using the Process class  and set the StandardOutput property of the Process instance with a stream reader you create  either based on a string or a memory location    After the process completes  you can then do whatever diff you need to on that stream

User · Answer

There is a ProcessHelper Class in PublicDomain open source code which might interest you

User · Answer

Here s a quick sample     Create process System Diagnostics Process pProcess   new System Diagnostics Process       strCommand is path and file name of command to run pProcess StartInfo FileName   strCommand     strCommandParameters are parameters to pass to program pProcess StartInfo Arguments   strCommandParameters   pProcess StartInfo UseShellExecute   false     Set output of program to be written to process output stream pProcess StartInfo RedirectStandardOutput   true        Optional pProcess StartInfo WorkingDirectory   strWorkingDirectory     Start the process pProcess Start       Get program output string strOutput   pProcess StandardOutput ReadToEnd       Wait for process to finish pProcess WaitForExit

User · Answer

You can launch any command line program using the Process class  and set the StandardOutput property of the Process instance with a stream reader you create  either based on a string or a memory location    After the process completes  you can then do whatever diff you need to on that stream

User · Answer

Julian s solution is tested working with some minor corrections  The following is an example that also used https   sourceforge net projects bat-to-exe  GenericConsole cs and https   www codeproject com Articles 19225 Bat-file-compiler program txt for args part  using System  using System Text     StringBuilder using System Diagnostics  using System IO    class Program       private static bool redirectStandardOutput   true       private static string buildargument string   args                StringBuilder arg   new StringBuilder            for  int i   0  i  lt  args Length  i                          arg Append  quot   quot  quot    args i     quot   quot   quot                       return arg ToString               static void Main string   args                Process prc   new Process            prc StartInfo     new ProcessStartInfo  quot cmd exe quot   String Format  quot  c   quot   quot  0   quot   1  quot   Path Combine Environment CurrentDirectory   quot mapTargetIDToTargetNameA3 bat quot    buildargument args               new ProcessStartInfo Path Combine Environment CurrentDirectory   quot mapTargetIDToTargetNameA3 bat quot    buildargument args            new ProcessStartInfo  quot mapTargetIDToTargetNameA3 bat quot            prc StartInfo Arguments   buildargument args            prc EnableRaisingEvents   true           if  redirectStandardOutput    true                        prc StartInfo UseShellExecute   false                    else                       prc StartInfo UseShellExecute   true                     prc StartInfo CreateNoWindow   true           prc OutputDataReceived    OnOutputDataRecived          prc ErrorDataReceived    OnErrorDataReceived            prc Exited    OnExited           prc StartInfo RedirectStandardOutput   redirectStandardOutput          prc StartInfo RedirectStandardError   redirectStandardOutput           try                       prc Start                prc BeginOutputReadLine                prc BeginErrorReadLine                prc WaitForExit                      catch  Exception e                        Console WriteLine  quot OS error   quot    e Message                      prc Close                  Handle the dataevent     private static void OnOutputDataRecived object sender  DataReceivedEventArgs e                  do something with your data         Console WriteLine e Data                Handle the error     private static void OnErrorDataReceived object sender  DataReceivedEventArgs e                Console WriteLine e Data                 Handle Exited event and display process information        private static void OnExited object sender  System EventArgs e                    var process   sender as Process            if  process    null                            Console WriteLine  quot ExitCode   quot    process ExitCode                         else                           Console WriteLine  quot Process exited quot                           The code need to compile inside VS2007  using commandline csc exe generated executable will not show console output correctly  or even crash with CLR20r3 error  Comment out the OnExited event process  the console output of the bat to exe will be more like the original bat console output

User · Answer

Start the child process   Process p   new Process        Redirect the output stream of the child process   p StartInfo UseShellExecute   false   p StartInfo RedirectStandardOutput   true   p StartInfo FileName    YOURBATCHFILE bat    p Start        Do not wait for the child process to exit before     reading to the end of its redirected stream      p WaitForExit        Read the output stream first and then wait   string output   p StandardOutput ReadToEnd     p WaitForExit      Code is from MSDN

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System Diagnostics ProcessStartInfo psi      new System Diagnostics ProcessStartInfo   program to call exe     psi RedirectStandardOutput   true   psi WindowStyle   System Diagnostics ProcessWindowStyle Hidden   psi UseShellExecute   false   System Diagnostics Process proc   System Diagnostics Process Start psi         System IO StreamReader myOutput   proc StandardOutput   proc WaitForExit 2000    if  proc HasExited            string output   myOutput ReadToEnd

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Since the most answers here dont implement the using statemant for IDisposable and some other stuff wich I think could be nessecary I will add this answer   For C  8 0     Start a process with the filename or path with filename e g   cmd   Please note the    using statemant using myProcess StartInfo FileName    cmd      add the arguments - Note add   c  if you want to carry out tge  argument in cmd and      terminate myProcess StartInfo Arguments     c dir      Allows to raise events myProcess EnableRaisingEvents   true    hosted by the application itself to not open a black cmd window myProcess StartInfo UseShellExecute   false  myProcess StartInfo CreateNoWindow   true     Eventhander for data myProcess Exited    OnOutputDataRecived     Eventhandler for error myProcess ErrorDataReceived    OnErrorDataReceived     Eventhandler wich fires when exited myProcess Exited    OnExited     Starts the process myProcess Start      read the output before you wait for exit myProcess BeginOutputReadLine       wait for the finish - this will block  leave this out if you dont want to wait for     it  so it runs without blocking  process WaitForExit        Handle the dataevent private void OnOutputDataRecived object sender  DataReceivedEventArgs e          do something with your data     Trace WriteLine e Data        Handle the error private void OnErrorDataReceived object sender  DataReceivedEventArgs e                Trace WriteLine e Data         do something with your exception     throw new Exception              Handle Exited event and display process information  private void OnExited object sender  System EventArgs e         Trace WriteLine  Process exited

User · Answer

Just for fun  here s my completed solution for getting PYTHON output - under a button click - with error reporting  Just add a button called  butPython  and a label called  llHello          private void butPython object sender  EventArgs e                llHello Text    Calling Python              this Refresh            Tuple lt String String gt  python   GoPython   C  Users BLAH Desktop Code Python BLAH py            llHello Text   python Item1     Show result          if  python Item2 Length  gt  0  MessageBox Show  Sorry  there was an error     Environment NewLine   python Item2              public Tuple lt String String gt  GoPython string pythonFile  string moreArgs                     ProcessStartInfo PSI   new ProcessStartInfo            PSI FileName    py exe           PSI Arguments   string Format     0     1    pythonFile  moreArgs           PSI CreateNoWindow   true          PSI UseShellExecute   false          PSI RedirectStandardError   true          PSI RedirectStandardOutput   true          using  Process process   Process Start PSI               using  StreamReader reader   process StandardOutput                                string stderr   process StandardError ReadToEnd       Error s                    string result   reader ReadToEnd       What we want                  return new Tuple lt String String gt   result stderr

User · Answer

There one other parameter I found useful  which I use to eliminate the process window  pProcess StartInfo CreateNoWindow   true    this helps to hide the black console window from user completely  if that is what you desire

User · Answer

You will need to use ProcessStartInfo with RedirectStandardOutput enabled - then you can read the output stream  You might find it easier to use   gt   to redirect the output to a file  via the OS   and then simply read the file    edit  like what Ray did   1

User · Answer

System Diagnostics ProcessStartInfo psi      new System Diagnostics ProcessStartInfo   program to call exe     psi RedirectStandardOutput   true   psi WindowStyle   System Diagnostics ProcessWindowStyle Hidden   psi UseShellExecute   false   System Diagnostics Process proc   System Diagnostics Process Start psi         System IO StreamReader myOutput   proc StandardOutput   proc WaitForExit 2000    if  proc HasExited            string output   myOutput ReadToEnd

User · Answer

The accepted answer on this page has a weakness that is troublesome in rare situations  There are two file handles which programs write to by convention  stdout  and stderr  If you just read a single file handle such as the answer from Ray  and the program you are starting writes enough output to stderr  it will fill up the output stderr buffer and block  Then your two processes are deadlocked  The buffer size may be 4K  This is extremely rare on short-lived programs  but if you have a long running program which repeatedly outputs to stderr  it will happen eventually   This is tricky to debug and track down   There are a couple good ways to deal with this    One way is to execute cmd exe instead of your program and use the  c argument to cmd exe to invoke your program along with the  2  amp 1  argument to cmd exe to tell it to merge stdout and stderr           var p   new Process            p StartInfo FileName    cmd exe           p StartInfo Arguments     c mycmd exe 2 gt  amp 1    Another way is to use a programming model which reads both handles at the same time            var p   new Process            p StartInfo FileName    cmd exe           p StartInfo Arguments      c dir  windows           p StartInfo CreateNoWindow   true          p StartInfo RedirectStandardError   true          p StartInfo RedirectStandardOutput   true          p StartInfo RedirectStandardInput   false          p OutputDataReceived     a  b    gt  Console WriteLine b Data           p ErrorDataReceived     a  b    gt  Console WriteLine b Data           p Start            p BeginErrorReadLine            p BeginOutputReadLine            p WaitForExit

User · Answer

Since the most answers here dont implement the using statemant for IDisposable and some other stuff wich I think could be nessecary I will add this answer   For C  8 0     Start a process with the filename or path with filename e g   cmd   Please note the    using statemant using myProcess StartInfo FileName    cmd      add the arguments - Note add   c  if you want to carry out tge  argument in cmd and      terminate myProcess StartInfo Arguments     c dir      Allows to raise events myProcess EnableRaisingEvents   true    hosted by the application itself to not open a black cmd window myProcess StartInfo UseShellExecute   false  myProcess StartInfo CreateNoWindow   true     Eventhander for data myProcess Exited    OnOutputDataRecived     Eventhandler for error myProcess ErrorDataReceived    OnErrorDataReceived     Eventhandler wich fires when exited myProcess Exited    OnExited     Starts the process myProcess Start      read the output before you wait for exit myProcess BeginOutputReadLine       wait for the finish - this will block  leave this out if you dont want to wait for     it  so it runs without blocking  process WaitForExit        Handle the dataevent private void OnOutputDataRecived object sender  DataReceivedEventArgs e          do something with your data     Trace WriteLine e Data        Handle the error private void OnErrorDataReceived object sender  DataReceivedEventArgs e                Trace WriteLine e Data         do something with your exception     throw new Exception              Handle Exited event and display process information  private void OnExited object sender  System EventArgs e         Trace WriteLine  Process exited

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usage const string ToolFileName    example exe   string output   RunExternalExe ToolFileName    public string RunExternalExe string filename  string arguments   null        var process   new Process         process StartInfo FileName   filename      if   string IsNullOrEmpty arguments                 process StartInfo Arguments   arguments             process StartInfo CreateNoWindow   true      process StartInfo WindowStyle   ProcessWindowStyle Hidden      process StartInfo UseShellExecute   false       process StartInfo RedirectStandardError   true      process StartInfo RedirectStandardOutput   true      var stdOutput   new StringBuilder        process OutputDataReceived     sender  args    gt  stdOutput AppendLine args Data      Use AppendLine rather than Append since args Data is one line of output  not including the newline character       string stdError   null      try               process Start            process BeginOutputReadLine            stdError   process StandardError ReadToEnd            process WaitForExit              catch  Exception e                throw new Exception  OS error while executing     Format filename  arguments          e Message  e              if  process ExitCode    0                return stdOutput ToString              else               var message   new StringBuilder             if   string IsNullOrEmpty stdError                         message AppendLine stdError                      if  stdOutput Length    0                        message AppendLine  Std output                 message AppendLine stdOutput ToString                        throw new Exception Format filename  arguments      finished with exit code       process ExitCode          message            private string Format string filename  string arguments        return       filename              string IsNullOrEmpty arguments     string Empty         arguments

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In case you also need to execute some command in the cmd exe  you can do the following      Start the child process  Process p   new Process       Redirect the output stream of the child process  p StartInfo UseShellExecute   false  p StartInfo RedirectStandardOutput   true  p StartInfo FileName    cmd exe   p StartInfo Arguments     C vol   p Start       Read the output stream first and then wait  string output   p StandardOutput ReadToEnd    p WaitForExit    Console WriteLine output     This returns just the output of the command itself     You can also use StandardInput instead of StartInfo Arguments      Start the child process  Process p   new Process       Redirect the output stream of the child process  p StartInfo UseShellExecute   false  p StartInfo RedirectStandardInput   true  p StartInfo RedirectStandardOutput   true  p StartInfo FileName    cmd exe   p Start       Read the output stream first and then wait  p StandardInput WriteLine  vol    p StandardInput WriteLine  exit    string output   p StandardOutput ReadToEnd    p WaitForExit    Console WriteLine output     The result looks like this

User · Answer

One-liner run command   new Process     StartInfo   new ProcessStartInfo  echo    Hello  World     Start      Read output of command in shortest amount of reable code       var cliProcess   new Process             StartInfo   new ProcessStartInfo  echo    Hello  World                 UseShellExecute   false              RedirectStandardOutput   true                      cliProcess Start        string cliOut   cliProcess StandardOutput ReadToEnd        cliProcess WaitForExit        cliProcess Close

User · Answer

There is a ProcessHelper Class in PublicDomain open source code which might interest you

User · Answer

Here s a quick sample     Create process System Diagnostics Process pProcess   new System Diagnostics Process       strCommand is path and file name of command to run pProcess StartInfo FileName   strCommand     strCommandParameters are parameters to pass to program pProcess StartInfo Arguments   strCommandParameters   pProcess StartInfo UseShellExecute   false     Set output of program to be written to process output stream pProcess StartInfo RedirectStandardOutput   true        Optional pProcess StartInfo WorkingDirectory   strWorkingDirectory     Start the process pProcess Start       Get program output string strOutput   pProcess StandardOutput ReadToEnd       Wait for process to finish pProcess WaitForExit

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usage const string ToolFileName    example exe   string output   RunExternalExe ToolFileName    public string RunExternalExe string filename  string arguments   null        var process   new Process         process StartInfo FileName   filename      if   string IsNullOrEmpty arguments                 process StartInfo Arguments   arguments             process StartInfo CreateNoWindow   true      process StartInfo WindowStyle   ProcessWindowStyle Hidden      process StartInfo UseShellExecute   false       process StartInfo RedirectStandardError   true      process StartInfo RedirectStandardOutput   true      var stdOutput   new StringBuilder        process OutputDataReceived     sender  args    gt  stdOutput AppendLine args Data      Use AppendLine rather than Append since args Data is one line of output  not including the newline character       string stdError   null      try               process Start            process BeginOutputReadLine            stdError   process StandardError ReadToEnd            process WaitForExit              catch  Exception e                throw new Exception  OS error while executing     Format filename  arguments          e Message  e              if  process ExitCode    0                return stdOutput ToString              else               var message   new StringBuilder             if   string IsNullOrEmpty stdError                         message AppendLine stdError                      if  stdOutput Length    0                        message AppendLine  Std output                 message AppendLine stdOutput ToString                        throw new Exception Format filename  arguments      finished with exit code       process ExitCode          message            private string Format string filename  string arguments        return       filename              string IsNullOrEmpty arguments     string Empty         arguments

User · Answer

This may not be the best easiest way  but may be an option   When you execute from your code  add     output txt  and then read in the output txt file

User · Answer

You can launch any command line program using the Process class  and set the StandardOutput property of the Process instance with a stream reader you create  either based on a string or a memory location    After the process completes  you can then do whatever diff you need to on that stream

User · Answer

In case you also need to execute some command in the cmd exe  you can do the following      Start the child process  Process p   new Process       Redirect the output stream of the child process  p StartInfo UseShellExecute   false  p StartInfo RedirectStandardOutput   true  p StartInfo FileName    cmd exe   p StartInfo Arguments     C vol   p Start       Read the output stream first and then wait  string output   p StandardOutput ReadToEnd    p WaitForExit    Console WriteLine output     This returns just the output of the command itself     You can also use StandardInput instead of StartInfo Arguments      Start the child process  Process p   new Process       Redirect the output stream of the child process  p StartInfo UseShellExecute   false  p StartInfo RedirectStandardInput   true  p StartInfo RedirectStandardOutput   true  p StartInfo FileName    cmd exe   p Start       Read the output stream first and then wait  p StandardInput WriteLine  vol    p StandardInput WriteLine  exit    string output   p StandardOutput ReadToEnd    p WaitForExit    Console WriteLine output     The result looks like this

User · Answer

System Diagnostics ProcessStartInfo psi      new System Diagnostics ProcessStartInfo   program to call exe     psi RedirectStandardOutput   true   psi WindowStyle   System Diagnostics ProcessWindowStyle Hidden   psi UseShellExecute   false   System Diagnostics Process proc   System Diagnostics Process Start psi         System IO StreamReader myOutput   proc StandardOutput   proc WaitForExit 2000    if  proc HasExited            string output   myOutput ReadToEnd

User · Answer

This might be useful for someone if your attempting to query the local ARP cache on a PC Server    List lt string   gt  results   new List lt string   gt              using  Process p   new Process                          p StartInfo CreateNoWindow   true              p StartInfo RedirectStandardOutput   true              p StartInfo UseShellExecute   false              p StartInfo Arguments     c arp -a               p StartInfo FileName     C  Windows System32 cmd exe               p Start                 string line               while   line   p StandardOutput ReadLine       null                                if  line        amp  amp   line Contains  Interface    amp  amp   line Contains  Physical Address                                          var lineArr   line Trim   Split      Select n   gt  n  Where n   gt   string IsNullOrEmpty n   ToArray                        var arrResult   new string                                        lineArr 0                      lineArr 1                      lineArr 2                                         results Add arrResult                                                p WaitForExit

User · Answer

This might be useful for someone if your attempting to query the local ARP cache on a PC Server    List lt string   gt  results   new List lt string   gt              using  Process p   new Process                          p StartInfo CreateNoWindow   true              p StartInfo RedirectStandardOutput   true              p StartInfo UseShellExecute   false              p StartInfo Arguments     c arp -a               p StartInfo FileName     C  Windows System32 cmd exe               p Start                 string line               while   line   p StandardOutput ReadLine       null                                if  line        amp  amp   line Contains  Interface    amp  amp   line Contains  Physical Address                                          var lineArr   line Trim   Split      Select n   gt  n  Where n   gt   string IsNullOrEmpty n   ToArray                        var arrResult   new string                                        lineArr 0                      lineArr 1                      lineArr 2                                         results Add arrResult                                                p WaitForExit

User · Answer

Start the child process   Process p   new Process        Redirect the output stream of the child process   p StartInfo UseShellExecute   false   p StartInfo RedirectStandardOutput   true   p StartInfo FileName    YOURBATCHFILE bat    p Start        Do not wait for the child process to exit before     reading to the end of its redirected stream      p WaitForExit        Read the output stream first and then wait   string output   p StandardOutput ReadToEnd     p WaitForExit      Code is from MSDN

User · Answer

The accepted answer on this page has a weakness that is troublesome in rare situations  There are two file handles which programs write to by convention  stdout  and stderr  If you just read a single file handle such as the answer from Ray  and the program you are starting writes enough output to stderr  it will fill up the output stderr buffer and block  Then your two processes are deadlocked  The buffer size may be 4K  This is extremely rare on short-lived programs  but if you have a long running program which repeatedly outputs to stderr  it will happen eventually   This is tricky to debug and track down   There are a couple good ways to deal with this    One way is to execute cmd exe instead of your program and use the  c argument to cmd exe to invoke your program along with the  2  amp 1  argument to cmd exe to tell it to merge stdout and stderr           var p   new Process            p StartInfo FileName    cmd exe           p StartInfo Arguments     c mycmd exe 2 gt  amp 1    Another way is to use a programming model which reads both handles at the same time            var p   new Process            p StartInfo FileName    cmd exe           p StartInfo Arguments      c dir  windows           p StartInfo CreateNoWindow   true          p StartInfo RedirectStandardError   true          p StartInfo RedirectStandardOutput   true          p StartInfo RedirectStandardInput   false          p OutputDataReceived     a  b    gt  Console WriteLine b Data           p ErrorDataReceived     a  b    gt  Console WriteLine b Data           p Start            p BeginErrorReadLine            p BeginOutputReadLine            p WaitForExit

User · Answer

You can launch any command line program using the Process class  and set the StandardOutput property of the Process instance with a stream reader you create  either based on a string or a memory location    After the process completes  you can then do whatever diff you need to on that stream

User · Answer

This may not be the best easiest way  but may be an option   When you execute from your code  add     output txt  and then read in the output txt file

User · Answer

This may not be the best easiest way  but may be an option   When you execute from your code  add     output txt  and then read in the output txt file

User · Answer

You will need to use ProcessStartInfo with RedirectStandardOutput enabled - then you can read the output stream  You might find it easier to use   gt   to redirect the output to a file  via the OS   and then simply read the file    edit  like what Ray did   1

User · Answer

You will need to use ProcessStartInfo with RedirectStandardOutput enabled - then you can read the output stream  You might find it easier to use   gt   to redirect the output to a file  via the OS   and then simply read the file    edit  like what Ray did   1

User · Answer

There one other parameter I found useful  which I use to eliminate the process window  pProcess StartInfo CreateNoWindow   true    this helps to hide the black console window from user completely  if that is what you desire

[c#] How To: Execute command line in C#, get STD OUT results

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