Messages in this thread |  | | | Date | Wed, 23 Mar 2005 07:11:53 -0500 (EST) | | From | linux-os <> | | Subject | Re: lseek on /proc/kmsg |
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On Wed, 23 Mar 2005, Jan Engelhardt wrote:
> > 1> Sure, read() needs to be modified to respect the file-position > 1> set by kmsg_seek(). I don't think you can get away with the > 1> call back into do_syslog. > > 2>I'm not sure that seek makes any sense on that, since it is more like a > 2>pipe than a normal file.. > > Well, seek(fd, 0, SEEK_END) could be used to flush a pipe's buffers. >
Yep. That's what I tried to do. Just returns 0 and continues to contain all the cached data.
> 0>> +static loff_t kmsg_seek(struct file *filp, loff_t offset, int origin) { > 0>> + if(origin != 2 /* SEEK_END */ || offset < 0) { return -ESPIPE; } > 3> "Allow" seeking past the end of the buffer? > > Well, what does lseek(fd, >0, SEEK_END) do on normal files? >
Goes to the end plus offset. A subsequent read returns EOF or 0 depending upon your read mechanism. This is what I wanted to do but with no offset.
Currently, I do this crap:
for(;;) { pfd.fd = ifd; pfd.events = POLLIN; pfd.revents = 0; if(poll(&pfd, 1, 0) <= 0) break; (void)read(ifd, ibuf, BUF_LEN); } I should be able to just lseek(ifd, 0 SEEK_END);
> -- >
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