On Tue, Dec 16, 2008 at 2:44 AM, Jeff King <peff@xxxxxxxx> wrote: > On Tue, Dec 16, 2008 at 01:35:53AM -0500, Stefan Karpinski wrote: > >> > On Mon, Dec 15, 2008 at 7:56 PM, Jeff King <peff@xxxxxxxx> wrote: >> > 2. detect EOF before starting the pager. We in fact already delay >> > running the pager in the forked process until we have some activity >> > on the pipe, but I don't know if there is a portable way of >> > detecting that that activity is EOF without performing an actual >> > read() call (which is undesirable, since it eats the first byte of >> > output that should go to the pager). >> >> Wouldn't ungetc work? Or is that not portable enough? (It would only >> work here because the EOF has to be the first character.) > > No, it won't work. ungetc works on the buffered stdio object, so it is > useful for pushing back characters onto the buffer to be read later in > the program from the same buffer. But in this case, we are going to > execv() (or on Windows, spawn) the pager, meaning it will throw away > anything that has been read() from the pipe and put in the buffer. > > So we would need a system call to push a character back to the OS, so > that it was available for read() by the pager process. Yeah, I realized that after I sent the message. Late night sending bad! -- To unsubscribe from this list: send the line "unsubscribe git" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
