On Sun, Jul 29, 2007 at 10:34:10AM -0700, Bryan O'Sullivan wrote:
GHC's file handles are backed by non-blocking file descriptors. The child process run by executeFile inherits the stdin, stdout and stderr file descriptors of your Haskell process, so they're unexpectedly (from its perspective) in non-blocking mode.
Due to POSIX sharing semantics, you can't simply switch those file descriptors to blocking in the child, because they'll then become blocking in the parent, too.
Yes, this would explain the behavior I'm seeing. My script neither forks nor reads stdin, so I could hack around this problem by clearing the O_NONBLOCK flag:
setFdOption stdInput NonBlockingRead False
Thanks for your help! Regards, -- Krzysztof Kościuszkiewicz Skype: dr.vee, Gadu: 111851, Jabber: kokr@jabberpl.org Mobile IRL: +353851383329, Mobile PL: +48783303040 "Simplicity is the ultimate sophistication" -- Leonardo da Vinci