I have file look like this...  abc100200300 abmen abc100200300 arcxi xyz200300300 aelmi   How do I print the lines that have duplicates (based on examining just the first 12 characters) to a separate file?  so in the separate file I should have  abc100200300 abmen abc100200300 arcxi
Given a file like this:  1,768,12,46576457,7898 1,123,435,134,146 2,345,6756856,12312,1311 5,234,567465,12341,1341 1,3245,4356345,2442,13 9,423,2342,121,463 9,989,342,121,1212   I would like to list all rows (in bash terminal) such that the value in column 1 appears at least twice (in column 1). The result should be  1,768,12,46576457,7898 1,123,435,134,146 1,3245,4356345,2442,13 9,423,2342,121,463 9,989,342,121,1212
What size should the HMAC key be with SHA-256? I'm trying to generate a secret key to be used for HMAC SHA-256 signature processing. I've seen many sample of keys with variable length from 32 characters to 96 characters.  What is the ironclad rule for this key size? How do I install a different Python version using apt-get? Over the past few weeks, there have been a number of complaints about users making suggested edits en masse whose quality was at least questionable.  Let an example of a low-quality edit be the addition of the web-frameworks tag to dozens of questions about the PHP web framework Laravel. No one is ever going to use it in a search, but Laravel is a framework, right?  (If you disagree about this being a low-quality edit, please  bear with me anyway - my point here is that the system through which such conflicts could be settled is broken.)   Examples          This is a toxic situation guaranteed to create strife because -   The new user is happy to have found a way to participate and earn some rep; they may be genuinely feeling that they are improving the site. The reviewers greenlighting most of their suggestions confirms them in their belief.   The reviewers usually see only one edit - and it's easy to see how they might go, "meh, this isn't a terribly useful edit, but hey, maybe it helps someone, and it's a new user. No point discouraging them."   The veteran users who check out the editor see dozens of what they perceive as low-quality edits, usually ignoring anything else that should be fixed in the post. To the veterans, the new user is systematically looking for excuses to make their pointless edits, creating a giant mess in order to  gain some rep - a mess they have to clean up, while there are no consequences for the editor, who gets to keep their ill-gotten points. While a bad question or answer can be downvoted - usually leading to a change of behaviour eventually - the edit system looks like it's wide open for gaming.   So tensions are high, and when there's dialog it can be angry. I'm not saying either side is completely right. I'm completely prepared to believe that many of these edits are in good faith, etc. But it's a mess because it's frustrating people. As said, there are no consequences for bad-faith mass editing; apart from commenting on some random post, there is no way to communicate with an editor. The outcome of a moderator flag is very much uncertain.  The absence of a clear set of rules means there's plenty of room for heated arguments.    Something needs to change here.  Either   We need super clear rules on what makes a good tag edit Tag-only edits should be allowed only for 2k+ users, or they should not gain 2 reputation points for &lt;2k users The possible 1000 rep gain for suggested edits needs to be rate-limited (say, 200 per month) (this is my favourite!) The possible 1000 rep gain for suggested edits needs to be lowered, say to 500 or 250 Rollbacks of suggested edits should result in annulment of the 2 points gained (this is terrible) There should be a system to vote on edits (yes, that's been suggested before) There should be a defined and officially sanctioned pathway, and ruleset, for moderator flags cast about these users    ... or something else. But something needs to give. Check if one list contains element from the other Dealing with suggested edits on question to be closed as duplicate There is a question on one of the SE sites that had a pending suggested edit: trust me, the way the original question was, it was needed. Before I even thought to approve the edit, I went to close it as a duplicate (as it was), but the suggested edit was still there.  If the question is being closed anyways (as a duplicate or otherwise) do I reject or approve the suggested edit? What is the proper etiquette? Seeking neighborhood boundaries globally? Besides Zillow's creative-commons licensed  shapefiles, what sources of neighborhood boundaries are there? Not just in the US, but all over the world.  Free/open source is ideal, but paid sources could be interesting too. What is ground and what does it do? Particular solution of $y''-4y'+5y = 4e^{2x} (\sin x)$ How do I find the particular solution of this second order inhomogenous differential equation? (Using undetermined coefficients).  $y''-4y'+5y = 4e^{2x} (\sin x)$  I can find the generel homogenous solutions but I need help for the particular. Would someone give a thorough explanation of 1.14 Minecraft's /data modify? Okay, so I've been searching all over the internet for an explanation of data modify ever since I heard Sethbling passively mention it in one of his videos. The only  thing I could find on it was the wiki and the update log for the 1.14 snapshot. So, I checked these, and they hardly explained it at all. I can get /data modify block 123 20 123... and that's as far as I get.  Minecraft wiki does not at all define clearly what  is (the thing meant to go after coords), nor does it specify what each operation does to what. Operations include (without explanation, and excluding set (which it does explain)): append, insert, merge, and prepend. Then, it has from|value as the next option, which aren't explained either. After this, it just has block/entity and coords/id. So, I know the format (mostly), but I haven't the slightest idea what any of it means. And nothing I've seen on the internet even mentions the command save for Minecraft wiki itself.  Please explain if you know what data modify is. Thanks! Binary Search in Array How would I implement a binary search using just an array? Does Windows Defender update if Windows Update is set to manual? I have the following content in in /etc/udev/rules.d/81-external-disk.rules:  ENV{ID_FS_UUID}=="6826692e-79f4-4423-8467-cef4d5e840c5", RUN{program}+="/bin/mount -o nofail,x-systemd.device-timeout=1 -t ext4 -U 6826692e-79f4-4423-8467-cef4d5e840c5 /backup/external"   After running:  udevadm control --reload ; udevadm trigger /dev/sdb1   It does nothing at all. However if II change the mount command for something such as /bin/touch /tmp/xyz it works.  Versions:  [root@helsinki rules.d]# rpm -qa | grep udev libgudev1-219-19.el7_2.12.x86_64 python-pyudev-0.15-7.el7_2.1.noarch [root@helsinki rules.d]# rpm -qa | grep systemd systemd-libs-219-19.el7_2.12.x86_64 systemd-219-19.el7_2.12.x86_64 systemd-sysv-219-19.el7_2.12.x86_64 [root@helsinki rules.d]# cat /etc/redhat-release  CentOS Linux release 7.2.1511 (Core) Why can a function modify some arguments as perceived by the caller, but not others? Are plants creatures or objects? This has occurred to me due to conflict between Fabricate and Blight. Fabricate says it can not target creatures and lists trees as example targets. Blight on the other hand can only target creatures and lists mundane normal plants as example targets.     Which of these conflicting spell descriptions is correct?    Note: It also occurred to me that plants might also be whichever one is convenient, unlikely but possible. Using The Terminal Command to Shutdown, Restart and Sleep My Mac? I'm getting more interested in using Terminal as an alternative way to address solutions on my Mac. I have seen this question entitled .  I would therefore like to know:  How to shut down, restart and sleep my Mac using the Terminal command exclusively ? How do I change my username? Some time ago, when I installed Ubuntu, I chose a rather stupid username for my account that I do not want to use anymore. How do I change this (including the name of my home directory, and the name in the terminal) without losing settings for applications? How do I keep permissions and my keys for various authentification (e.g. email, SSH, GPG and more)? What settings could possibly get lost if I changed my username? How was this character poisoned in Warcraft? In Warcraft, towards the end of movie we observe the Guardian Medivh changing sides and starting to emit green light instead of blue. I might have missed that part or misunderstood but how exactly did he get poisoned? I've only just begun studying group theory (up to Lagrange) following on from vector spaces and I am still finding them almost frustratingly  arbitrary. I'm not sure what exactly it is about the axioms that motivated them defining groups.  My textbook asks you to list 'common features' of vector spaces and then later defines a set of axioms for vector spaces under addition, scalar multiplication and both, noting that the axioms under addition form an Abelian group. So are groups just a generalisation of vector spaces under any binary operation?  My main problem is that the book notes that 'the axioms may seem rather arbitrary' and links groups with vector spaces but doesn't elaborate.   When introducing groups, you are tasked to complete Cayley tables for the symmetries of an equilateral triangle and square.  Then, similarly to the delivery of vector spaces, notes that the tables have common properties (Closure, Identity, inverse and association) and defines a group as a set of elements under a binary operation that has these features.  So what's so important about these 4 properties? For example, if 1 or 2 the properties were excluded form the  axioms, or we added an extra few properties as axioms how would that cripple the effectiveness of groups?  Are the group axioms ever difficult to work with or do they always work, forgive the crude Littlewood analogy, like a mathematical skeleton key?  What is it about these 4 properties that make groups such a powerful tool in mathematics and physics?  My best guess is that a group is the best way to express our sense of  symmetry and what is symmetric mathematically, but I would prefer some elaboration. How do I remove code duplication between similar const and non-const member functions? Today a couple of buffer overflows in NTP were announced , . It looks like updating my system to fix these issues is in order.   How can I find out if they have been fixed in the Ubuntu repositories, such that if I were to run:   sudo apt-get update sudo apt-get upgrade   then the fix would get installed and the vulnerability closed?   Edit: The selected answer specifically addresses the question of how to identify if a given CVE has been fixed or not, "Does Ubuntu generally post timely security updates?"  is certainly related but not identical