[Bug 61360] Re: magic string for "Bio-Rad .PIC" is too relaxed
** Changed in: file (Ubuntu) Status: Confirmed => Fix Released -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/61360 Title: magic string for "Bio-Rad .PIC" is too relaxed To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/file/+bug/61360/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
[Bug 61360] Re: magic string for "Bio-Rad .PIC" is too relaxed
** Changed in: file (Debian) Status: Fix Committed => Fix Released -- magic string for "Bio-Rad .PIC" is too relaxed https://bugs.launchpad.net/bugs/61360 You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
[Bug 61360] Re: magic string for "Bio-Rad .PIC" is too relaxed
Also, era, that was good work figuring out the source of the bug; it made writing the patch far easier. Thank you. If you're interested in tricks and methods for writing magic matches, have a look at the existing magic; it covers a vast variety of file types along with a corresponding vast variety of approaches used to detect patterns. -- magic string for "Bio-Rad .PIC" is too relaxed https://bugs.launchpad.net/bugs/61360 You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
[Bug 61360] Re: magic string for "Bio-Rad .PIC" is too relaxed
** Changed in: file (Debian) Status: Unknown => Fix Committed -- magic string for "Bio-Rad .PIC" is too relaxed https://bugs.launchpad.net/bugs/61360 You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
[Bug 61360] Re: magic string for "Bio-Rad .PIC" is too relaxed
Magic lines which match but don't emit any text can be used to require multiple matatching patterns before returning a positive hit. I've put together a patch; it's attached to the upstream Debian bug report. ** Bug watch added: Debian Bug tracker #589056 http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=589056 ** Also affects: file (Debian) via http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=589056 Importance: Unknown Status: Unknown -- magic string for "Bio-Rad .PIC" is too relaxed https://bugs.launchpad.net/bugs/61360 You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
[Bug 61360] Re: magic string for "Bio-Rad .PIC" is too relaxed
Same problem in Hardy with a simple .txt file... (see the attached example) ** Attachment added: "test.txt" http://launchpadlibrarian.net/13290897/test.txt -- magic string for "Bio-Rad .PIC" is too relaxed https://bugs.launchpad.net/bugs/61360 You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
[Bug 61360] Re: magic string for "Bio-Rad .PIC" is too relaxed
I tried to come up with a patch for this, but the constraints of the file format make it a bit challenging. The basic problem is that the "magic number" 12345 decimal was a very poor choice, because it translates to the ASCII sequence "90" (or "09" in big-endian). Because there is no mechanism for backtracking, magic(5) requires you to commit to a particular file type based on a single decision, and no such decision appears to be straightforwardly possible for this file type. (There is a proposal for a backtracking-like mechanism in http://mx.gw.com/pipermail/file/2005/000110.html but I don't think it has gone anywhere.) The convoluted workaround I had been playing around with would basically use a heuristic, long regular expression for matching several of the "magic" Bio-Rad fields in a "string match" but I believe this wasn't really possible either last time I looked at it (regex matching would not cope with strings with zero bytes in them, if I recall at all correctly), and relied on file(1) features which were not really mainstream. Anyway, for the Ubuntu package, I speculate that very little harm would ensue if this detection were simply removed from the file(1) database. -- magic string for "Bio-Rad .PIC" is too relaxed https://bugs.launchpad.net/bugs/61360 You received this bug notification because you are a member of Ubuntu Bugs, which is the bug contact for Ubuntu. -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
