On 23 October 2014 06:24, John Wiersba > wrote: > Maybe I'm confused. Isn't the purpose of run.exe to start a > cygwin program without creating a (visible) console window? > I can just start a cygwin program directly without the indirection of > run.exe if I don't care about the random flashing console window. > > From the run.exe manpage: > run will do this for you. It works as intermediate and starts a program > but makes the console window hidden.
AFAIK, all programs that run in Windows need a window handle in order to receive events, and to pass to a lot of windows functions. If your program create a windows before it tries to do anything that requires a window, that window gets used. When your program does not create its own windows, the start up code tries to attach you to an existing console window, and if there is not one, it creates it. A Windows GUI program starts at winmain(). This entry point does not have the same requirements as the C standard main() entry point. Mainly, you do not have the stdin, stdout, and stderr attached to anything, and you do not have a window. Creating a console or GUI window is entirely up to your code. Normally, any non-GUI program will attach to the console window where it starts. A "dos" type program will attach to the window running the cmd.exe that started it, and a cygwin program will get attached to the mintty console window to which your shell is attached, For both types of non-GUI programs, the msvcrt.dll or cygwin1.dll runtime code will setup stdin, stdout and stderr before entering main(). The runtime startup code will create a console window for you if you did not inherit one from your parent process, and the code will attach those file pointers to the console window In any system: Windows, cygwin, linux, or whatever, to create a windowless process, you close those initial file pointers or file handles and fork a new process. In the original process, you close your window if necessary, you call exit(), and the runtime will close your window if necessary. In the new process, you do what ever you want. When you have a cmd.exe window, you use "start" to fire off a new program and control what happens to its window with command line options. When you have a shell in a cygwin console, you use "run.exe" at the shell prompt. When you use a shortcut, you have not initial window, so the msvcrt.dll runtime creates one for you, and uses the properties of the shortcut to control how that window is created. At the shell prompt, try the following commands: $ /cygdrive/c/windows/system32/notepad.exe $ /cygdrive/c/windows/system32/notepad.exe & $ run /cygdrive/c/windows/system32/notepad.exe $ run /cygdrive/c/windows/system32/notepad.exe & use ps to check how the notepad process is connected to cygwin. Try exiting the shell after the second command to see why you want to use run. Anyway, that's how I think things work. But I may be wrong. It may give you some ideas on where to look for more correct and/or detailed answers. Doug -- Doug Henderson, Calgary, Alberta, Canada -- Problem reports: http://cygwin.com/problems.html FAQ: http://cygwin.com/faq/ Documentation: http://cygwin.com/docs.html Unsubscribe info: http://cygwin.com/ml/#unsubscribe-simple
