I am a beginner in Regular expressions and  I want to check if a string variable satisfy a specified expression like this :   R|numeric_value|^value0^^^value1|value2|value_or_null|date_value   Note : The symbols (| and ^) are mandatory static characters and they are considered as Fields delimiters  any one help please!  Thanks in advance
I am tired of always trying to guess, if I should escape special characters like '()[]{}|' etc. when using many implementations of regexps.  It is different with, for example, Python, sed, grep, awk, Perl, rename, Apache, find and so on. Is there any rule set which tells when I should, and when I should not, escape special characters? Does it depend on the regexp type, like PCRE, POSIX or extended regexps?
Splitting vector layer in R gnome-software on Ubuntu 16.04 doesn't work From Awodey: In any category $\mathsf{C}$,  an object $0$ is initial if for any object $C$ there is a unique morphism $0 \to C$,  an object $1$ is terminal if for any object $C$ there is a unique morphism $C \to 1$.  First I was puzzled by the fact that we can do mappings from a zero set to any other set in a category $\mathsf{Sets}$. But then after I accepted it conceptually, I do not understand why there is no unique morphism to an empty set from every object in a category $\mathsf{Sets}$. Is this because we cannot map a non-empty set to an empty set (since our mapping is total) although we can map an empty set to a non-empty set?  Please, note, I am familiar with the proposition saying: Initial (terminal) objects are unique up to isomorphism. How do I count the number of occurrences of a char in a String? Do you need to erase the memory of *watching* a memory in a Pensieve? You remove your memory from your brain to store in a Pensieve (as Snape or Dumbledore did). Then, you re-watch the memory (e.g. as Dumbledore re-watched his memories of Voldemort's investigations with Harry) in the Pensieve.   Does that mean that you now re-created the memory in your brain (because you remember watching it) and thus you'll need to extract/erase it from your brain again if you don't wish to keep it there for security/capacity reasons (which was why you stored it in the Pensieve in the first place?  Canon answers only please. I have  with a bounty that will expire in a few days. It looks like nobody will get the bounty; only one answer was posted during the bounty period, and it has no upvotes.  In cases like this, the bounty is thrown away.  Why isn't it refunded instead, if no answerer has earned it? Why aren’t my villagers breeding? I’ve got one villager up 7 blocks surrounded with 6 doors. On ground level I have villagers who are supposed to breed. They are willing, their inventories are full of potatoes, and I’ve been sitting here for hours.  Hearts are popping up above their heads but nothing happens. I am playing on Xbox One. Please explain the meaning of "otherwise than" in this sentence Please explain the meaning of the second part and explain "otherwise than" in part b     a person’s UK property business consists of:      (a) every business which the person carries on for generating income from land in the United Kingdom; and      (b) every transaction which the person enters into for that purpose otherwise than in the course of such a business. Unix Truncate Column in csv file What does it mean for a QFT to not be well-defined? It is usually said that QED, for instance, is not a well-defined QFT. It has to be embedded or completed in order to make it consistent. Most of these arguments amount to using the renormalization group to extrapolate the coupling up to a huge scale, where it formally becomes infinite.  First of all, it seems bizarre to me to use the renormalization group to increase resolution (go to higher energies). The smearing in the RG procedure is irreversible, and the RG doesn't know about the non-universal parts of the theory which should be important at higher energies.   I have read in a note by Weinberg that Kallen was able to show that QED was sick using the spectral representation of the propagator. Essentially, he evaluated a small part of the spectral density and showed that it violated the inequalities for the field strength $Z$ that are imposed by unitarity + Lorentz invariance, but I do not have the reference.  So what I would like to know is :   What does it take to actually establish that a QFT is not well-defined?   In other words, if I write down some arbitrary Lagrangian, what test should I do to determine if the theory actually exists. Are asymptotically free theories the only well-defined ones?   My initial thought was: We would like to obtain QED (or some other ill-defined theory) using the RG on a deformation of some UV CFT. Perhaps there is no CFT with the correct operator content so that we obtain QED from the RG flow. However, I don't really know how to make that precise.   Any help is appreciated. I read this book a few years back (around 5?). It was part of a multibook series but I have only read one book.  It's about this teenager who I think had been programmed to be an assassin but then somehow retained his conscience and was out to get the people responsible for that.  I briefly remember a girl, and this one part where he realizes he can ride a horse and then there's a chase too. I think the guy's name was Jim or Jimmy, but not quite. I'm also quite sure he was either part computer, or had a chip or something in his brain which had been programmed to give him a host of mental and physical abilities which he retained and used as well as the series progressed. I'm splitting a string by three different characters but I want the output to include the characters I split by. Is there any easy way to do this? What does "upgrade to 18.04" mean? I'm using Ubuntu 16.04 LTS on an Asus K53E laptop with 8 GB RAM. I check for updates to the software daily. If there are no updates, it asks me if I want to upgrade? What does upgrade exactly mean? Will my personal files still be there? Will it wipe EVERYTHING and give me a completely new installation of Ubuntu? Or will it allow me to keep my files and applications, and merely upgrade the OS?  When I upgrade my Mac or Windows machines, my personal files remain available after the upgrade. Does Ubuntu do the same, or are there completely different "rules"? Looking for a powershell script that can pull a file from a set of PC's and FTP I'm looking to write a script (preferably powershell) that will essentially copy a file from a bunch of PC's and FTP it to a server.   So the structure of the environment is that we have a file on multiple PC's (around 50 or so) that need to placed on a server. Sometimes one of the PC's may be turned off so the script would first need to ensure the PC is up and running (maybe a ping result), then it would need to go into a directory on that PC, pull a file off of it, rename the file, place into a source directory, then remove the file. Naming convention doesn't matter, but date/time stamp would be easiest. Ideally, it would be best to first move all the files to a source directory to save on FTP bandwidth, but since the files will be named the same, the files must be renamed during the move process. Move not copy because the directory needs to be empty so the file can be re-created the next day. So once moved to the source directory, now all the files need to be FTP'd to a server for processing.   After all of this, we need to know which PC's on the list did not respond so we can manually retrieve the file so the script should output a file (txt is fine) that will show which PC's were offline.   Everything is one domain and script will be run from an server with admin creds.   Thank you! SharePoint 2013 Online - Missing Follow Link Why do we say "is it" when asking a question rather than "it is"? What it says on the tin, a foreign friend of mine has asked and I can't tell him; apart from it sounding horrible.  For example:  "Why is it raining today?"   Instead of:  "Why it is raining today?" Adding two numbers concatenates them instead of calculating the sum Word meaning you are describing something as if to a child Looking for a word that describes the feeling of being told something in an overly simplified manner that feels offensive. I would like to define a theorem environment with custom layout. In particular, I want the body of the theorem to be indented, like this  Text body. Text body. Text body.  Theorem 1 (Pythagoras).     Let a,b,c the sides of a rectangular triangle.     Without loss of generality, we assume that  a&lt;b&lt;c .     Then, the following equality holds:            a^2 + b^2 = c^2  More text. And even more text.   This is similar to the quote environment, I believe.  How can I do this?  Preferably, I would like to use the existing \newtheorem command, but that's not mandatory. How to create this curved shadow in Photoshop? How to create the shadow effect like the URL/image below? Specifically, the rounded/curved shadow at the bottom: