I have set ulimit for open files on my centos machine by editing /etc/security/limits.conf post which I am unable to login into the machine.  This was the change made in /etc/security/limits.conf file.    nofiles unlimited    A tail of verbose output of my ssh login is as follows.  debug1: client_input_channel_req: channel 0 rtype exit-status reply 0 debug1: client_input_channel_req: channel 0 rtype eow@openssh.com reply 0 debug2: channel 0: rcvd eow debug2: channel 0: close_read debug2: channel 0: input open -&gt; closed debug2: channel 0: rcvd eof debug2: channel 0: output open -&gt; drain debug2: channel 0: obuf empty debug2: channel 0: close_write debug2: channel 0: output drain -&gt; closed debug2: channel 0: rcvd close debug3: channel 0: will not send data after close debug2: channel 0: almost dead debug2: channel 0: gc: notify user debug2: channel 0: gc: user detached debug2: channel 0: send close debug2: channel 0: is dead debug2: channel 0: garbage collecting debug1: channel 0: free: client-session, nchannels 1 debug3: channel 0: status: The following connections are open:   #0 client-session (t4 r0 i3/0 o3/0 fd -1/-1 cfd -1)  debug3: channel 0: close_fds r -1 w -1 e 6 c -1 debug3: Wrote 32 bytes for a total of 2229 debug3: Wrote 64 bytes for a total of 2293 Connection to 172.16.47.108 closed. Transferred: sent 2096, received 2528 bytes, in 0.0 seconds Bytes per second: sent 91488.9, received 110345.4 debug1: Exit status 254   A ping to the machine works fine and give back replies. Then why is my ssh connection getting terminated.
I need to start by stating that I have read through every single problem on here relating to mine, but all of them seem to have access somehow to their server's files. I do not, so here is my question.  I'm on centOS 6.5 and ssh closes connection right after a successful login. I am using mac and windows/putty to access my server with the same results. Is there anyway I can access my server now without having access to its files?   Below is the readout from ssh -vvv right after a successful login:  debug1: Authentication succeeded (password). Authenticated to 4X.5X.XX.2 ([4X.5X.XX.2]:82). debug1: channel 0: new [client-session] debug3: ssh_session2_open: channel_new: 0 debug2: channel 0: send open debug1: Requesting no-more-sessions@openssh.com debug1: Entering interactive session. debug2: callback start debug2: fd 3 setting TCP_NODELAY debug3: ssh_packet_set_tos: set IP_TOS 0x10 debug2: client_session2_setup: id 0 debug2: channel 0: request pty-req confirm 1 debug1: Sending environment. debug3: Ignored env TERM_PROGRAM debug3: Ignored env SHELL debug3: Ignored env TERM debug3: Ignored env TMPDIR debug3: Ignored env Apple_PubSub_Socket_Render debug3: Ignored env TERM_PROGRAM_VERSION debug3: Ignored env TERM_SESSION_ID debug3: Ignored env USER debug3: Ignored env SSH_AUTH_SOCK debug3: Ignored env __CF_USER_TEXT_ENCODING debug3: Ignored env PATH debug3: Ignored env PWD debug1: Sending env LANG = en_US.UTF-8 debug2: channel 0: request env confirm 0 debug3: Ignored env XPC_FLAGS debug3: Ignored env XPC_SERVICE_NAME debug3: Ignored env SHLVL debug3: Ignored env HOME debug3: Ignored env LOGNAME debug3: Ignored env _ debug2: channel 0: request shell confirm 1 debug2: callback done debug2: channel 0: open confirm rwindow 0 rmax 32768 debug2: channel_input_status_confirm: type 99 id 0 debug2: PTY allocation request accepted on channel 0 debug2: channel 0: rcvd adjust 2097152 debug2: channel_input_status_confirm: type 99 id 0 debug2: shell request accepted on channel 0 Last login: Wed Oct  7 06:23:21 2015 from 1XX.XXX.X1.185 debug1: client_input_channel_req: channel 0 rtype exit-status reply 0 debug1: client_input_channel_req: channel 0 rtype eow@openssh.com reply 0 debug2: channel 0: rcvd eow debug2: channel 0: close_read debug2: channel 0: input open -&gt; closed debug2: channel 0: rcvd eof debug2: channel 0: output open -&gt; drain debug2: channel 0: obuf empty debug2: channel 0: close_write debug2: channel 0: output drain -&gt; closed debug2: channel 0: rcvd close debug3: channel 0: will not send data after close debug2: channel 0: almost dead debug2: channel 0: gc: notify user debug2: channel 0: gc: user detached debug2: channel 0: send close debug2: channel 0: is dead debug2: channel 0: garbage collecting debug1: channel 0: free: client-session, nchannels 1 debug3: channel 0: status: The following connections are open:   #0 client-session (t4 r0 i3/0 o3/0 fd -1/-1 cc -1)  Connection to 4X.5X.XX.2 closed. Transferred: sent 3176, received 2640 bytes, in 0.3 seconds Bytes per second: sent 10370.6, received 8620.4 debug1: Exit status 254
Screensaver with active desktop I am running XP and im looking for a screensaver that does not change the desktop. I.e when the screensaver is active, i want to be able to see my desktop as it is and any changes on the desktop to be visible. Only if i touch the mouse should the login prompt be displayed to inactive the screensave.   For example, i am usually either working on my desktop or laptop. On my desktop i have an applicaiotn running that is showing me stock quotes from the stock exchange. Everytime the screensaver activates i have to touch the mouse to bring the screen back.   What i want to be able to do, is to be working on my laptop and at any time look at the numbers on my desktop without the screensaver interfering. I want the screensaver to be active but its only job is to ask me to enter the password to unlock the screen. I should still be able to see teh stock prices as tehy are changing even while the screensaver is active.   Basicly is it possible to see the desktop while the screensaver is active?   Thanks What is the maximum number of people that will join a settlement? I've got two settlements on the go that I'm paying attention to - Sanctuary and the Starlight Drive In. Both of these settlements have radio towers and beds and all resources in the green however they appear to have stopped growing at 10 people in each settlement even though happiness is above 80 and I've got 15+ beds at each location.  What is the maximum number of people that will join a settlement? Is is possible to restore the MFT of a NTFS partition after a format? I've searched through several questions but didn't quite find anyone treating mine.  So, I have a 1TB external hard drive I use for backup purposes with only 1 NTFS partition. Today using DiskPart I formated that partition by mistake (who would have thought the disc count started in 0 and not in 1). The complete command I used was:  format recommended override quick label=Windows   So I performed a quick format, and from which I've read after a quick format it's possible to recover the data stored there. Anyway, as soon as I realized it wasn't the partition I wanted to format the one I specified I removed the access to my external drive to minimize possible damages.  Now, the MFT is the metadata part where the file name, creation date, access permissions and contents are registered; and it's mirrored too (so there's a copy of it somewhere in the disk). What I don't know is if a quick format erases that MFT mirror too, I hope not.  I'm running a program to recover files on it but I'll have to save the files to another location (once it's finished scanning, ~12 hours from now) and I don't quite have over 900GB of free storage where to put the data.  I would like to know if there's a program or procedure by which I could restore the old MFT in-place and have all the data that used to be in there accessible once again.  Any help or light you could shed on how to proceed or what programs to use is really appreciated. Can there be true conclusions without assumptions? I was thinking of the sentence  "I think therefore I am",  which I had for a long time considered indisputable because it's self-evident.   Then I considered the hypothetical situation where my thoughts are illogical – and of course I can't be aware that they are – and so to a logical outsider I am not saying something that is actually indisputable and self-evident, but in fact may be total nonsense. Perhaps there is a hypothetical evil demon altering my ability to reason. However convincing it seems to me that I MUST exist since, in whatever since "I" or "exist" is, there is the ability to question whether I do, the conclusion can't actually be trusted without doubt since I cannot know if I am in fact reasoning logically.  Even what I consider to be trivial tautologies require this assumption of sanity, and therefore there is no true conclusion without assumption – an assumption about the nature of my own reasoning. The only absolute truth I have is unspeakable subjective experience, and any articulation (and I realize the apparent circular reasoning I've cornered myself into here...) is necessarily uncertain.  I realize that perhaps this doesn't even make sense, but was just curious if anyone had entertained this line of thought and come to some satisfying resolution. What exactly is weakly informative prior? Is there a precise definition of weakly informative prior?  How is it different from a subjective prior with broad support? I don't understand an answer. Should I add a comment, or post a new question? I recently (today) asked a question that received what seems to be a clear, concise answer, but one that's beyond my ability to understand (I'm at the cut-and-paste stage with JavaScript, and the answer seems to assume more knowledge than I actually have).  Is it considered better to ask follow-up questions as comments to the answer given, or should I post "fresh" questions to Stack to help me understand the answer that's been given? I had recently entered the UK without a visa to be with my partner, from 21 July 2016 until 16 December 2016. I hope to return on the 9th of January. We don't meet the income requirement for a Spouse visa. I recently applied to university, and got in, and was intending to return to the UK on a student visa, but my university did not tell me about maintenance fees and my loan wasn't large enough to cover it all, so my visa would have been denied.  Now, I am hoping to attend university in the next semester, and therefore return to the US to apply for that visa. Do you think that if I try to return to the UK without a visa, I will be turned away?  I won't be working or studying during this time, however, I'm afraid that they'll consider it living in the UK illegally; I don't have a criminal record or anything like that. Non-perpendicular hyperplane decision trees The usual implementation of decision trees, and estimators based on ensembles of decision trees, use decision trees that threshold on a single predictor at each split. So they divide the feature space into perpendicular hyperlanes.  Is there any benefit to generalizing this a tiny bit. So at each split, the decision tree uses 2 features, and thresholds based on whether $ax_1 + bx_2 \ge T$. In other words, the feature space is now getting divided into hyperplanes that are not necessarily perpendicular.   I think the main disadvantages would be:    increased computation, and  overfitting since now using more degrees of freedom   I guess to help both of these issues, randomization could be used analogous to extra trees. The pair of features could be randomly selected, instead of exhaustively trying every pair, and the threshold T and parameters a and b could be chosen randomly as well (perhaps from a set of few discrete values such that the hyperplanes could have a few orientations).  Are there some cases where you think these non-perpendicular decision trees would be an improvement over the regular implementation of various decision tree algorithms? What's the best way to draw UML class diagrams in LaTeX? Is it possible to create a counter just with wiring? With the new logic gates in the 1.3.1 update, is it possible to create some wiring circuit that counts how many times a trigger was activated? In other words, is it possible to make a circuit that outputs a trigger every two input triggers?  I've done some experimenting but the nature of wires and there being no intrinsic on/off state in Terraria makes it pretty counter-intuitive compared to real world logic circuits. What are the prerequisites for studying mathematical logic? I am looking to study mathematical logic, however, I find that introductory books are very daunting, which kind of disheartens me. You see, slowly but surely, I started to realize that the maths which I have learned did not just pop out of thin air, but is a collection of systems, which must of been developed via some other system, i.e, maths did not develop itself.  So I began to look into the origins of mathematics, and read that it was developed via a type of logic, which exists sort of by 'default', via a set of axioms, and then of course I looked up the definition of axioms.   So given that I'd be studying a type of logic whose origins are self evident axioms, naturally I believed there would be no prerequisites. However, in looking up mathematical logic, I have come across things such as Boolean algebra, sets, first order logic, some other type of logic, called 'traditional logic', as well as references to a sort of calculus, though not in a mathematical sense, I think.  So all in all, I am trying to develop a type of mental spider web, and I am trying to find out the strands which lye at the absolute bounds so that I may learn this mystique logic. Though I have no idea where to start.  Side note: This is the book I have started reading:   Credit goes to Wolfgang Rautenberg. Why are extra dimensions necessary? Some theories have more than 4 dimensions of spacetime. But we only observe 4 spacetime dimensions in the real world, cf. e.g.  Phys.SE post.   Why are the theories (e.g. string theory) that require more dimensions taken seriously by scientists?  Is there any proof that these extra dimensions exist? Is there a simple layman's explanation for the need [or strong hint] for extra dimensions? Reference template variable within Jinja expression What are the use cases of SO_REUSEADDR? I have used SO_REUSEADDR to have my server which got terminated to restart with out complaining that the socket is already is in use. I was wondering if there are other uses of SO_REUSEADDR? Have anyone used the socket option for other than the said purpose? Show that Function Compositions Are Associative My intent is to show that a composition of bijections is also a bijection by showing the existence of an inverse.  But my approach requires the associativity of function composition.  Let $f:  X \rightarrow Y, g:  Y \rightarrow Z, h:  Z \rightarrow W$ be functions.  $((f \circ g) \circ h)(x) = h((f \circ g)(x)) = h(g(f(x)))$, and $(f \circ (g \circ h))(x) = (g \circ h)(f(x)) = h(g(f(x)))$.  However, I am having problems in justifying that the two compositions, $(f \circ g) \circ h$ and $f \circ (g \circ h)$, have the same domain and range.  When I consulted ProofWiki, whose link is at the bottom, I got even more confused.  Specifically, for $(f \circ g) \circ h = f \circ (g \circ h)$ to be defined, ProofWiki requires that dom$g =$ codom$f$ and dom$h =$ codom$g$.  First of all, I think that it should be dom$g =$ range$f$ ....  Moreover, as you can see in the example below, you actually have to adjust domains and ranges of $f, g, h$ for the requirement to hold true.  Let $f: \mathbb R \rightarrow \mathbb R$ be $f(x) = 2x$, $g: \mathbb R^+ \rightarrow \mathbb R$ be $g(y) = ln(y)$, $h: \mathbb R \rightarrow \mathbb R$ be $h(z) = z - 10$.   Then $((f \circ g) \circ h)(x) = ln(2x) - 10 = (f \circ (g \circ h))(x)$, with dom$((f \circ g) \circ h) = \mathbb R^+$ = dom$(f \circ (g \circ h))$.  As a result, we need to set dom$f = \mathbb R^+$, range$f = \mathbb R^+$; dom$g$, range$g$, dom$h$, and range$h$ remain the same.  Am I allowed to do that?  This adjustment implies that when we say dom$f = X$, $f$ must be defined for all elements in $X$, but $X$ may not be the entire set of elements for which $f$ is defined. I have a Python script which I would like to execute at every startup. I can run it by adding this to the startup applications:  python3 /path/to/script.py   That works, but it doesn't open a terminal window, so I can't see the program's output. How could I make it open a terminal window and execute the script in there?  Note: I get the window to stay open with input(' ') at the end of the Python script. Thanks! Explanation of finite population correction factor? I understand that when sampling from a finite population and our sample size is more than 5% of the population, we need to make a correction on the sample's mean and standard error using this formula:  $\hspace{10mm} FPC=\sqrt{\frac{N-n}{N-1}}$  Where $N$ is the population size and $n$ is the sample size.  I have 3 questions about this formula:   Why is the threshold set at 5%? How was the formula derived? Are there other online resources that comprehensively explain this formula besides  paper? (Reference : Fraleigh, A first course in abstract algebra)     Prove that a nonempty set $G$, together with an associative binary operation * on $G$ such that $a*x=b$ and $y*a=b$ have solutions in G, $\forall a,b\in G$, is a group.   Because * is an associatie operation, we have to prove that: there exists $e\in G$ such that $e*a=a=a*e$ for any $a\in G$, and that for any $a\in G$ there exists $\alpha \in G$ such that $a*\alpha=e=\alpha *a$.  This is very confusing, first I tried to prove the identity exists. If we consider a=b, then $a*x=a=y*a$, and because of the hypothesis $x,y\in G$ always exists, now we have to show that $x=y$, but I just can't do this with out inverses, so I tried to prove that the inverses exists, however I have no idea how the identity looks like, I'm stuck.  And I tried to get unstuck, so I thought particular cases, first if $G$ had only one element, then what would happend if it had just two elements... but I remembered that we don't know if G is finite or not, and I think this makes things a little bit more complicated.  What can I do? I am extremely poor in solving a problem quickly, which leaves me doing badly in olympiads and other contests. But, if I just don’t give up on a problem, no matter how much time it takes, I usually end up solving it. To have a future in mathematics or physics, is it necessary for me to excel at contests, because these days children excelling at contests have an advantage over those who don’t (not complete advantage, but advantage nonetheless)? How can I combine multiple rows into a comma-delimited list in Oracle? I have a simple query:  select * from countries   with the following results:  country_name ------------ Albania Andorra Antigua .....   I would like to return the results in one row, so like this:  Albania, Andorra, Antigua, ...   Of course, I can write a PL/SQL function to do the job (I already did in Oracle 10g), but is there a nicer, preferably non-Oracle-specific solution (or may be a built-in function) for this task?  I would generally use it to avoid multiple rows in a sub-query, so if a person has more then one citizenship, I do not want her/him to be a duplicate in the list.  My question is based on the similar question on .  UPDATE: My function looks like this:  CREATE OR REPLACE FUNCTION APPEND_FIELD (sqlstr in varchar2, sep in varchar2 ) return varchar2 is ret varchar2(4000) := ''; TYPE cur_typ IS REF CURSOR; rec cur_typ; field varchar2(4000); begin      OPEN rec FOR sqlstr;      LOOP          FETCH rec INTO field;          EXIT WHEN rec%NOTFOUND;          ret := ret || field || sep;      END LOOP;      if length(ret) = 0 then           RETURN '';      else           RETURN substr(ret,1,length(ret)-length(sep));      end if; end;