> The point is that it's not about cygwin-vs-windoze apps. It's about
> apps-that-use-console-stdin-and-stdout vs. apps-that-display-a-gui; those
> that show a gui could usefully be detached, but those that read their input
> from stdin will break if the shell detaches them.
Yes, you're right, the old "native" zsh option was specifically to do with GUI
apps rather than "Windows" apps per se - here's the doc to for enabling the
option (it was off by default):
winntwaitforguiapps: When set, makes the shell wait for win32 GUI apps to
terminate instead of spawning them asynchronously.
> I don't think there's a reliable enough mechanism by which a shell could
> detect one case from the other.
Below is the code it used to determine if a program is a GUI program or not. I
don't know how well it works under all conditions; however it did work fine for
me.
Even if not perfectly reliable, could something like this be added but disabled
by default? I for one would find it useful.
--- John
/*
How To Determine Whether an Application is Console or GUI [win32sdk]
ID: Q90493 CREATED: 15-OCT-1992 MODIFIED: 16-DEC-1996
*/
#include <winnt.h>
#define xmalloc(s) HeapAlloc(GetProcessHeap(),HEAP_ZERO_MEMORY,(s))
#define xfree(p) HeapFree(GetProcessHeap(),0,(p))
#define XFER_BUFFER_SIZE 2048
int is_gui(char *exename) {
HANDLE hImage;
DWORD bytes;
DWORD SectionOffset;
DWORD CoffHeaderOffset;
DWORD MoreDosHeader[16];
ULONG ntSignature;
IMAGE_DOS_HEADER image_dos_header;
IMAGE_FILE_HEADER image_file_header;
IMAGE_OPTIONAL_HEADER image_optional_header;
hImage = CreateFile(exename, GENERIC_READ, FILE_SHARE_READ, NULL,
OPEN_EXISTING, FILE_ATTRIBUTE_NORMAL, NULL);
if (INVALID_HANDLE_VALUE == hImage) {
return 0;
}
/*
* Read the MS-DOS image header.
*/
if (!ReadFile(hImage, &image_dos_header, sizeof(IMAGE_DOS_HEADER),
&bytes,NULL)){
CloseHandle(hImage);
return 0;
}
if (IMAGE_DOS_SIGNATURE != image_dos_header.e_magic) {
CloseHandle(hImage);
return 0;
}
/*
* Read more MS-DOS header. */
if (!ReadFile(hImage, MoreDosHeader, sizeof(MoreDosHeader),
&bytes,NULL)){
CloseHandle(hImage);
return 0;
}
/*
* Get actual COFF header.
*/
CoffHeaderOffset = SetFilePointer(hImage, image_dos_header.e_lfanew,
NULL,FILE_BEGIN);
if (CoffHeaderOffset == (DWORD) -1){
CloseHandle(hImage);
return 0;
}
CoffHeaderOffset += sizeof(ULONG);
if (!ReadFile (hImage, &ntSignature, sizeof(ULONG),
&bytes,NULL)){
CloseHandle(hImage);
return 0;
}
if (IMAGE_NT_SIGNATURE != ntSignature) {
CloseHandle(hImage);
return 0;
}
SectionOffset = CoffHeaderOffset + IMAGE_SIZEOF_FILE_HEADER +
IMAGE_SIZEOF_NT_OPTIONAL_HEADER;
if (!ReadFile(hImage, &image_file_header, IMAGE_SIZEOF_FILE_HEADER,
&bytes, NULL)){
CloseHandle(hImage);
return 0;
}
/*
* Read optional header.
*/
if (!ReadFile(hImage, &image_optional_header,
IMAGE_SIZEOF_NT_OPTIONAL_HEADER,&bytes,NULL)) {
CloseHandle(hImage);
return 0;
}
CloseHandle(hImage);
if (image_optional_header.Subsystem ==IMAGE_SUBSYSTEM_WINDOWS_GUI)
return 1;
return 0;
}
int is_9x_gui(char *prog) {
char *progpath;
DWORD dwret;
char *pathbuf;
char *pext;
pathbuf=xmalloc(MAX_PATH);
progpath=xmalloc(MAX_PATH<<1);
if (GetEnvironmentVariable("PATH",pathbuf,MAX_PATH) ==0) {
goto failed;
}
pathbuf[MAX_PATH]=0;
dwret = SearchPath(pathbuf,prog,".EXE",MAX_PATH<<1,progpath,&pext);
if ( (dwret == 0) || (dwret > (MAX_PATH<<1) ) )
goto failed;
dprintf("progpath is %s\n",progpath);
dwret = is_gui(progpath);
xfree(pathbuf);
xfree(progpath);
return dwret;
failed:
xfree(pathbuf);
xfree(progpath);
return 0;
}
--- John
-----Original Message-----
From: Dave Korn [mailto:[EMAIL PROTECTED]
Sent: 15 June 2004 15:40
To: 'John Cooper'; [EMAIL PROTECTED]
Subject: RE: Ctrl-Z fails to suspend Windows programs
> -----Original Message-----
> From: cygwin-owner On Behalf Of John Cooper
> Sent: 15 June 2004 15:05
> To: cygwin
> Subject: RE: Ctrl-Z fails to suspend Windows programs
>
> The old native (non-cygwin) port of zsh would somehow detect if it was
> about to exec a Windows app, and run it as a background process, thus
> returning a zsh prompt immediately. Could something like this be
> added to cygwin bash/zsh?
AFAICS the ability is already there. Just enter "windows_app.exe &" at a bash shell.
> This was very useful. With the cygwin zsh, I often find myself
> invoking a Windows app and not being able to get back to the shell
> window without first terminating the Windows app.
Well, the same goes if you run a cygwin app: you don't get the prompt back until it
exits.
The point is that it's not about cygwin-vs-windoze apps. It's about
apps-that-use-console-stdin-and-stdout vs. apps-that-display-a-gui; those that
show a gui could usefully be detached, but those that read their input from
stdin will break if the shell detaches them. I don't think there's a reliable
enough mechanism by which a shell could detect one case from the other.
Try starting insight (gui version of gdb) from the bash prompt. You also won't
get a shell back until it exits.
cheers,
DaveK
--
Can't think of a witty .sigline today....
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