title: What's the easiest way to send a string to another application? (Win API)
body: <p>I have two Win32 API programs written in plain C: Program A and program B. I want program B to send the string "Hello World" to program A. So B needs to do the following:</p>
  
  <p>1) Detect if program A is running.</p>
  
  <p>2) If it is, send "Hello World" string to A.</p>
  
  <p>3) If A is not running, B should show an error message.</p>
  
  <p>Can someone point me to the API functions necessary to do this? How would I establish such a communication between two programs? I think the biggest problem is that the "Hello World" string is in the address space of program B and it somehow needs to move to the address space of A. So just passing a memory pointer is not sufficient... I need a different approach. Any ideas?</p>
  
  <p>Thanks</p>