in certain situations lseek() will return successful although no seek was performed. this can happen when operating on devices that don't support seeking (older tape drives) or when operating on changeable media devices (such as DVD or Blu-ray devices) without a medium inserted. the attached patch fixes the lseek(2) man page by adding several entries to the BUGS section, along with updating the POSIX compliance to the latest specifications. please note that the real issue doesn't seem fixable atm. lseek() was never designed to confirm a seek operation, but to merely request it. the issue was extensively discussion in this thread: http://lists.freebsd.org/pipermail/freebsd-hackers/2011-November/036842.html (alternative link: http://docs.freebsd.org/cgi/mid.cgi?20111115202450.GA73512) cheers. alex Fix: Patch attached with submission follows:
Responsible Changed From-To: freebsd-bugs->freebsd-doc Over to maintainer(s).
here's a revised patch (comma removed after "confirm"), as suggested by warren block. thanks. :) cheers. alex
Responsible Changed From-To: freebsd-doc->eadler I'll take it.
Responsible Changed From-To: eadler->freebsd-doc I won't be looking at this PR for a while and I need to clear some out of my queue
For bugs matching the following criteria: Status: In Progress Changed: (is less than) 2014-06-01 Reset to default assignee and clear in-progress tags. Mail being skipped
A commit references this bug: Author: gbe Date: Mon Jul 13 15:52:58 UTC 2020 New revision: 363156 URL: https://svnweb.freebsd.org/changeset/base/363156 Log: lseek(2): Document the seek behavior better and update the POSIX compliance In certain situations lseek(2) will return successful although if no seek was performed. This can happen when operating on devices that don't support seeking (older tape drives) or when operating on changeable media devices (such as DVD or Blu-ray devices) without a medium inserted. Document this within the man page and update the POSIX compliance while here. PR: 162765 Submitted by: arundel@ Reported by: arundel@ Reviewed by: bcr (mentor) Approved by: bcr (mentor) MFC after: 1 week Differential Revision: https://reviews.freebsd.org/D25646 Changes: head/lib/libc/sys/lseek.2
A commit references this bug: Author: gbe Date: Mon Jul 20 16:48:46 UTC 2020 New revision: 363370 URL: https://svnweb.freebsd.org/changeset/base/363370 Log: MFC r363156: lseek(2): Document the seek behavior better and update the POSIX compliance PR: 162765 Submitted by: arundel@ Reported by: arundel@ Reviewed by: bcr (mentor) Approved by: bcr (mentor) MFC after: 1 week Differential Revision: https://reviews.freebsd.org/D25646 Changes: _U stable/12/ stable/12/lib/libc/sys/lseek.2