On 2017-03-13, Grant Edwards <grant.b.edwa...@gmail.com> wrote: > After upgrading to a new version of busybox (1.25.1), I now have an > odd problem with 'cat'. When stdout is a file, it _appears_ to be > doing a seek to the beginning of the output file between input files.
[...] > But, strace doesn't show any seeks. I see that 'cat' is using > sendfile mutiple times. According to sendfile(2): > > In Linux kernels before 2.6.33, out_fd must refer to a socket. Since > Linux 2.6.33 it can be any file. If it is a regular file, then send‐ > file() changes the file offset appropriately. > > Apparently "change file file offset apprpriatly" means it gets reset > to zero after every call to sendfile(). I take it this implementation > of 'cat' works for other people? Apologies for the noise -- I finally stumbled across CONFIG_FEATURE_USE_SENDFILE, and disabling that fixes the 'cat' problem with 2.6.33 kernels. -- Grant Edwards grant.b.edwards Yow! I smell a RANCID at CORN DOG! gmail.com _______________________________________________ busybox mailing list busybox@busybox.net http://lists.busybox.net/mailman/listinfo/busybox