John Summerfield wrote: > [EMAIL PROTECTED] ~]$ yes stuff | head -300 | cat -n | (head -2;tail -2) > 1 stuff > 2 stuff > [EMAIL PROTECTED] ~]$ > > I presume this arises because head's reading ahead (if not head, then > glibc on head's behalf), and when head's printed enough lines it simply > closes its files (or maybe just exit()s.
yep. > I don't see when this behaviour might actually be desired. I'd like to > see its behaviour changed so that head consumes no more lines than it > will report. (I note the man page is silent on what should happen, no > surprise there). It works as you expect only for seekable (rewindable) file descriptors. > If you think that the current unpredictable behaviour is sometimes > desirable, then could we please have something, maybe --nobuffer, to > turn it off? Have a look at the "stdio input buffering problems" here: http://www.pixelbeat.org/programming/stdio_buffering/ Note the referenced patch on that page will have no affect with head, as it doesn't use stdio to read data. Pádraig. _______________________________________________ Bug-coreutils mailing list Bug-coreutils@gnu.org http://lists.gnu.org/mailman/listinfo/bug-coreutils
