windows: is it possible to dump (direct) a text file into a named pipe

Question

I have a setup where a program gets its input like so:

1) user enters a command in a command prompt

2) the text from the command prompt is written to a named pipe

3) a process on the other side of the pipe is reading the input parse and execute the command

I would like to have the ability to store a set of commands in a text file and then have the named pipe feed of the text file.

is there some way to chine the pipe and the file together? or do I need to read the text file and split it into lines which I will write to the pipe one by one

Answer 1

You should be able to use TYPE:

TYPE "filename" | myprogram.exe

Though this won't work if you explicitly require a named pipe, or need to pipe into an already-running process.

Though in that case, you could use a stub program which writes its STDIN to the named pipe.

Answer 2

If you use named pipe it might be possible,

if you take a look at this, you can see they use plain CreateFile to open the pipe, taking a look at that, it seems you cannot redirect but you have to read and write, at least with the API is the same ReadFile WriteFile.

void WriteToPipe(void) 

// Read from a file and write its contents to the pipe for the child's STDIN.
// Stop when there is no more data. 
{ 
   DWORD dwRead, dwWritten; 
   CHAR chBuf[BUFSIZE];
   BOOL bSuccess = FALSE;

   for (;;) 
   { 
      bSuccess = ReadFile(g_hInputFile, chBuf, BUFSIZE, &dwRead, NULL);
      if ( ! bSuccess || dwRead == 0 ) break; 

      bSuccess = WriteFile(g_hChildStd_IN_Wr, chBuf, dwRead, &dwWritten, NULL);
      if ( ! bSuccess ) break; 
   } 

// Close the pipe handle so the child process stops reading. 

   if ( ! CloseHandle(g_hChildStd_IN_Wr) ) 
      ErrorExit(TEXT("StdInWr CloseHandle")); 
}