And looking through the source code on os.exec_linux I think I've also
validated this as well:
if fd[i] == i {
// dup2(i, i) won't clear close-on-exec flag on Linux,
// probably not elsewhere either.
_, _, err1 = RawSyscall(fcntl64Syscall, uintptr(fd[i]), F_SETFD, 0)
if err1 != 0 {
goto
It appears this was in fact the issue.
I added some code to print out the `FD_CLOEXEC` state. Files called via
*syscall.Dupe2* end up with a *FD_CLOEXEC=0* whereas anything passed via
*ExtraFiles* has a *FDCLOEXEC=1.*
Whoever said "This is impossible" thanks - you spurred me towards a
I think I may have discovered the issue.
I made a sys call to duplicate the file descriptor
dupFd, err := syscall.Dup(int(file.Fd()))
if err != nil {
log.Printf("Error duplicating file descriptor: %v", err)
return 0, ""
}
which likely reset the FD_CLOEXEC Flag:
(from Advanced Programming in
OP here -> I'm going to put together some test apps - toss them on GitHub
and make sure I actually know what I'm talking about :)
On Friday, March 1, 2024 at 7:57:15 PM UTC-7 Ian Lance Taylor wrote:
> On Fri, Mar 1, 2024 at 6:17 PM Robert Engels wrote:
> >
> > The could be calling fork() as
On Fri, Mar 1, 2024 at 6:17 PM Robert Engels wrote:
>
> The could be calling fork() as in the system call - which copies all file
> descriptors but I didn’t think Go processes could fork.
>
> Seems you would need to remap stdin and stdout in the fork to do anything
> useful.
>
> This sounds
The could be calling fork() as in the system call - which copies all file
descriptors but I didn’t think Go processes could fork.
Seems you would need to remap stdin and stdout in the fork to do anything
useful.
This sounds very PHP - what goes around comes around.
> On Mar 1, 2024, at 8:01
On Fri, Mar 1, 2024 at 5:57 PM Jeff Stein wrote:
>
> I'm struggling to understand if I'm able to do something.
>
>
> In my very odd use case we are writing a websever that handles connections
> via a forked process.
>
> I have a listener process that listens for TCP connections.
>
> So each
I'm struggling to understand if I'm able to do something.
In my very odd use case we are writing a websever that handles connections
via a forked process.
I have a listener process that listens for TCP connections.
So each net.Conn that comes in we pull off its file descriptor:
*fd, err :=
