site_archiver@lists.apple.com Delivered-To: darwin-dev@lists.apple.com User-agent: Mozilla Thunderbird 1.0.2 (Macintosh/20050317) Juan Manuel Palacios wrote: [] The evidence: 1) In screen.c, there is a line, conditioned on #ifdef __APPLE__ if (_vprocmgr_move_subset_to_user(real_uid, "Background") != NULL) -- Martin _______________________________________________ Do not post admin requests to the list. They will be ignored. Darwin-dev mailing list (Darwin-dev@lists.apple.com) Help/Unsubscribe/Update your Subscription: http://lists.apple.com/mailman/options/darwin-dev/site_archiver%40lists.appl... I don't have a solution to the problem, but at least a few words of comfort telling you that I'm also experiencing the exact same problem: Tiger's screen, OK; MacPorts' screen, OK; Leopard's screen, no PATH. I have to supply the full path to whatever program I want to run under Leopard's screen, otherwise I get not found errors. Thanks. I have now looked some more at the source code, in particular at the Apple-specific patches, and I am now seeing the point where the deed is done. But I am hitting a wall there. To me (but what do I know) it looks like there is some private undocumented code at work here, something that smells of Solaris; but that's about the extent of what I am understanding. That function _vprocmgr_move_subset_to_user comes from a private header vproc_private.h, and I haven't found it documented. 2) in windows.c, there is code replacing execve by a call to /usr/bin/login with the flags "-pflq". Indeed, if you run /usr/bin/screen on Leopard and look at the started processes with 'ps x', you see a process "login -pflq". Now the "-l" flag to login is nowhere documented, as far as I can see. These two things play together: - If you only remove 1 and leave 2 in place, screen does not work, it quits immediately. If you remove both of them, you get standard screen behavior with the usual unclobbered PATH and no additional login process. - If you leave 1 and 2 in place and only remove the "l" flag from "-pflq", you get an unclobbered PATH, too. - I was not able to test "login -pflq" at the command line, it gives an error message. This seems to hint that this flag in 2 needs 1 for running. In conclusion, the cause of this problem seems to be an undocumented "feature" of Leopard's /usr/bin/login that is used by Apple's variant of /usr/bin/screen. Why they are doing this, I cannot imagine. This email sent to site_archiver@lists.apple.com