Asri-unix.380 net.unix-wizards utzoo!decvax!ucbvax!menlo70!sri-unix!dpk@BMD70 Wed Dec 30 23:29:28 1981 Re: who one two three four five six From: Doug Kingston The strange behavior that Robert Owens was talking about is one of possible results of having stray file descriptors left open by the invoking program. It all depends on how that error is handled (Try again.). I am not saying that this has to be his problem, but it might be. A while ago I send an inquiry to U-W asking if there were any problems with changing popen to close all file descriptors except 0, 1, and 2 before it execed the program. One response correctly urged caution in changing anything like POPEN, another mentioned that one might want to pass an open file descriptor to a child. While this is certainly possible, it would be very bad form. The program would have to know which file descriptor to use or have it passed as a command line arg (UGH!). We would consider asking people to use pipe, fork, and exec for these cases. (Note, we do not have IOCTL close on exec ... But soon ...). Any other thoughts on this matter? Cheers, Doug Kingston PS. What does CSH do to open file-descripters when it is execed? ----------------------------------------------------------------- gopher://quux.org/ conversion by John Goerzen of http://communication.ucsd.edu/A-News/ This Usenet Oldnews Archive article may be copied and distributed freely, provided: 1. There is no money collected for the text(s) of the articles. 2. The following notice remains appended to each copy: The Usenet Oldnews Archive: Compilation Copyright (C) 1981, 1996 Bruce Jones, Henry Spencer, David Wiseman.