When I ssh between different pcs I can omit my username (tom) and just type   ssh pc_name   instead of   ssh tom@pc_name   I like this feature, and have got into the habit of using it.  Unfortunately, on one of my computers I went for the user name tommy.  Everytime I connect to this computer I forget to write tommy@creative_pc and wonder why my password doesn't work.  Is there a way to tell ssh what user name to use when the username is omitted?  Edit: Just found the following question that is similar:   It didn't come up on my initial search.
I use ssh on a variety of machines, mainly linux. Accounts on these machines vary in naming scheme: if my name is First Last, then I have accounts: first, flast, last_f, lastf, and sometimes I need to log in as root. For each machine I use, I would like the openssh client to know which account to use when I don't specify on the command line.  So the question is: How do I make ssh server Do The Right Thing when a username is not specified?
I know that a perpetual motion machine (a device that produces work without an energy source) would violate several physical laws, the first that comes to mind being the . I also understand that a claim that perpetual motion is possible would probably not be congruent with the scientific method, occum's razor, etc.  What I am interested in is whether there exists some logical and intuitively meaningful (to they lay person) demonstration that perpetual motion is universally impossible, based only on axioms rooted in observable physical phenomena, rather than the obvious reasons why it is merely improbable and incompatible with some of our physical laws.  Certain violations of physical laws, such as travelling faster than the speed of light, can be shown to be unlikely as they would cause paradoxes or logical impossibilities, such as a . In that instance, the axioms needed to establish a paradox (time dilation) are empirically observable, and a counter-claim would require the existence of new paradox-resolving laws that are not established, or the permission of paradoxes which is difficult to imagine.  Conversely, the idea that some invention is impossible on the basis of its violation of a physical law alone is difficult because it requires a .  So, without relying on the assertion that a physical law is omnipresent (e.g. conservation of energy), is there some impossibility or logical paradox that would arise from the existence of a machine that could produce work without indefinitely without an energy source?  Finally, I'm very aware that perpetual motion is a bit of a dirty word and will likely touch a nerve with people, so please take the time to let me know how I can make this question less offensive and avoid the inevitable down-votes. limit of Holder norms: $\sup\limits_{x\in [a,b]} f(x) = \lim\limits_{n\rightarrow\infty} \left(\int_a^b (f(x))^n \;dx\right)^{\frac{1}{n}}$ Show that $$\sup_{x\in [a,b]} f(x) = \lim_{n\rightarrow\infty} \left(\int_a^b (f(x))^n \;dx\right)^{\frac{1}{n}}$$ for f continuous and positive on [a,b].  I can show that LHS is greater than or equal to RHS but I can't show the other direction. What can be considered as "Home ties" for a UK Standard Visitor visa (PLAB)? I am an Indian national who recently cleared his PLAB1 examination and has booked to sit PLAB2 in UK (which can be given only in UK). Before applying for a visa, I would like to know about the how one can prove home ties. Of course, I have read about the Family, Job, Property being used as ties but...  I haven't worked since my graduation (two years now) as I wasted a lot of precious time on USMLE. After that IELTS and then PLAB1. So can't show job as tie.  I don't have any property in my name but my father does have residential plots and agricultural lands worth a few crores on his name.    Does an affidavit that I am his only son and heir to all that bla bla bla, serve the purpose?  I do have few life insurance policies in my name.  Can they be used as an indicator of some kind of active Indian society member thingy?  I am unmarried but do intend to show my parents as family ties.   I did my medical studies in China (6-7 years). I have also traveled to a few countries like Russia, Thailand, Philippines, HK, Macau etc etc (though not a single Western country).    Can that be used in my favour in home ties that I have always obeyed country's laws and returned to India upon completion of the purpose of the trip? How Many Genius Mixes Are There in iTunes? How do you do Impersonation in .NET? Is there a simple out of the box way to impersonate a user in .NET?  So far I've been using  for all my impersonation requirements.  Is there a better way to do it by using .NET Framework?  I have a user credential set, (username, password, domain name) which represents the identity I need to impersonate. I am having a problem running the CDC change capture job against some of my test databases.  The error message I'm getting is the following:     Executed as user: NT AUTHORITY\NETWORK SERVICE. Cannot execute as the database principal because the principal "dbo" does not exist, this type of principal cannot be impersonated, or you do not have permission. [SQLSTATE 42000] (Error 15517).   How can I fix this? How to make different materials for different objects? When I change one material, it changes it on another object. Why and how do I fix it? is there some link between the objects?    Here is my blender file of Iron Man's faceplate.  Here is my whole screen with the main portion of the face selected. On the right, you can see the material, and I can tell you that that is the same as the eyes part: Variational Derivation of Schrodinger Equation How can I start to learn web development? I'm very interested in learning web development and have learned some basics regarding HTML and CSS a few years back from W3Schools, but I never learned how to develop websites that are up to today's standards, i.e. free-flowing sites without the use of tables to govern the design of the site.  What are some good resources that I can start with? Do superheroes/villains like Quicksilver or Flash with super speed get tired due to running? I mean a average human can run at his full speed for 15 to 20 mins before getting tired. Trained athletes can go on running for much more time without tiring out.  Do Superheroes like Quicksilver or Flash ever get tired due to excessive running? New Div - "Hiding questions because of your Ignored Tags preferences for tags" I think this message/div/box was just added today since I've never noticed it before, it is very noticeable.    I'm already aware that I'm hiding questions because I selected to hide them in my preferences. Isn't this a bit redundant? Now I have to scroll down more to be able to click to the next page. Plus see that same message dozens upon dozens of times a day.    Here are my ignored tags. So I'm going to have to see the same message on any question page that I'm on. Even though I already know questions are being hidden. I'm not understanding the point to this new div/box notification.  Does anyone find this new div/box useful? Do you find it redundant?       EDIT:   Also, this isn't just for StackOverflow.   I only have 2 ignored tags for CodeReview currently. And I have it set for only 15 questions per page. But still, on every page I click to it shows! Can "cattle" be singular? I've grown up on a farm, and my dad and his dad, apparently, always used "cattle" to refer to both the singular and plural forms of the domestic bovine. I've always assumed it's how the word "deer" is.  However, I've heard people say that this is incorrect and the singular is just "cow", but this has always offended us as a cow is a mother cattle, and is incorrect if you're referring to a steer, a bull, or a heifer.  So, is cattle singular as well as plural? If not, is there some general, non-gender-specific word that should be used instead? I'm trying to find a post I made on my timeline (aka wall) several months (or even years) ago, but can't find a way to search for it. I , but that's very heavy.   Currently, I open the activity log (e.g., https://www.facebook.com/username/allactivity) and start scrolling down to get some info on the page. Then I use my browser to search for the text. But this is slow and, depending on how far back I want to go, tedious. Clicking on the earliest month/year in the filter only loads those periods specifically.    Anyone know of a better way that will find the search words anywhere on your activity log quickly?    Edit: There's a  (not really a bug, but lack of a feature) related to this on Facebook's developers forum. Can I choose to use only Shapiro-Wilk? Quotient rings of Gaussian integers I used this isomorphism today but now I'm having trouble justifying it. The norm function isn't additive so I can't come up with a ring isomorphism to prove the following:     For any $\,a+bi\in\Bbb Z[i],\,\gcd(a,b)=1$, we have a ring isomorphism   $$\Bbb Z[i]/\langle a+bi\rangle\,\cong\Bbb Z/(a^2+b^2)\Bbb Z=:\Bbb Z_{a^2+b^2}.$$   Could someone show me an isomorphism between these rings to prove this? Omission of the indefinite article to eliminate ambiguity love between husband and wife   What is the reason that there is no article (e.g. "love between a husband and a wife") in the above? Has some kind of a rule been identified grammatically when it comes to such a case? If I were to guess I think it's because the indefinite article 'a', the purpose of that, is taking a generic sample (or 'instance') from a 'class' (the class of husbands), but in the above sentence you want to refer to the class itself... the husband class and the wife class... and not an 'instance' of them, because it just is more to the point. Do you think this is a fair reasoning? Also, a thought came to me that with the use of the indefinite article, you get a generic husband and a generic wife, which, may not necessarily love each other (for they are not a specific pair of a specific husband and a specific wife who in fact love each other). Soft version of the maximum function? In the book Deep Learning, it says the softmax function is de facto a soft argmax function, and the corresponding soft version of the maximum function is $$\text{softmax} (z)^T z$$ How to understand the latter? SQL Query; Admin Log System; Foreign Keys; Retriving multiple rows form different tables at once Table A (users)  id     | name   | ip 52433    Yashas   1.1.1.1 512      Admin    5.6.7.8   Table B (admin_record)  id    | admin | time    | date    | reason | action  52433   512     2312352   1213213   Test     WARN   id is FOREIGN key  Table B keeps a log of all actions an administrator takes on his users. And the table A stores the account information of the users &amp; administrators.  I am trying to display a list of actions taken by a administrators on a user.   I want to write a query which gets me all the rows of table B where id = fixed number.  Here is what I want to display:  "Administrator1 [Name]" took action on "User Name" for "[Note]" on XX/XX/XXXX. "Administrator2 [Name]" took action on "User Name" for "[Note]" on XX/XX/XXXX. "Administrator3 [Name]" took action on "User Name" for "[Note]" on XX/XX/XXXX.   All I have is the user's id using which I need to obtain all the entries in the log along with the administrator names. I need to obtain the admin's name, users name and all the contents of table B related to a particular user in one single query. If possible, I want the to change the field name(not literally change, but want the SQL server to send the data with new field names to separate admin name &amp; user name) of the admin's name to admin_name and user's name as . I mean something like this  SELECT users.name AS admin_name WHERE users.id = %i  AND SELECT users.name AS user_name WHERE users.id = %i   (the query isn't correct,it us just an example to show what I am trying)  Progress so far:   SELECT player.name, player.ip, admin.name, record.date, record.time, record.action, record.reason FROM admin_record AS record JOIN users AS player ON player.id = record.id JOIN users AS admin ON admin.id = record.admin WHERE player.id=%i   where admin_record is table B &amp; users is table A. Use #ifdefs and #define to optionally turn a function call into a comment Is it possible to do something like this  #ifdef SOMETHING #define foo // #else #define foo MyFunction #endif   The idea is that if SOMETHING is defined, then calls to foo(...) become comments (or something that doesn't get evaluated or compiled), otherwise it becomes a call to MyFunction.  I've seen __noop used, but I don't believe I can use that.  EDIT(s):  I don't think I can really use a macro here, because MyFunction takes a variable number of arguments.  Also, I'd like to make it so the arguments are NOT evaluated!  (So doing something like commenting out the body of MyFunction doesn't really give me what I need, as the arguments will still be evaluated) Unable to install ECW support on lubuntu 14.04