I have a 1TB big file (disk-image from a damaged drive) and a 1.3MB small file (beginning of a disk-file).  Using the contents of the small file, I want to overwrite portions of the big file. That is, I want to insert/overwrite the first 1.3MB of the 1TB-image using the small file.  Using small temporary files for testing I was unable to overwrite parts of the files. Rather, dd overwrote the files completely. This is not what I want.  Is dd able to do this?
I have an empty file (only zeroes are in it) of size 9,0KB and I need to write another file (with size 1,1KB) to it, but the first file must not lose its size or the rest of its contents. So if the whole file is 00000000000000... now, I need to write second file in it and leave the zeroes as they are. I have tried to use dd, but I haven't succeed - file resizes.  dd if=out/one.img of=out/go.img   Does anybody know how can I do it?
What does the '=>' syntax in C# mean? I just came over this syntax in some of the questions in this forum, but Google and any other searchengine tends to block out anything but letters and number in the search so it is impossible to search out "=>".  So can anyone tell me what it is and how it is used? Trouble with Vakil's FOAG exercise 11.3.C I'm having trouble with the exercise in the title, even with part (a), which asks to prove that if $X$ is a closed subset of $\mathbb{P}^n_k$ of dimension at least 1 and $H$ is a non-empty hypersurface, then $X$ and $H$ meet.   Following the hint, I've done the following: By assumption, $X$ is given by $V(I)$ for some homogenous prime ideal $I\subset k[x_0,\dots x_n]=:A$ and $H$ by $V(f)$ for some homogenous polynomial $f\in A$. We wish to prove that there is a homogenous prime ideal $\mathfrak{p}$ (that's not the irrelevant one) containing both $I$ and $f$.  Consider the affine cone $\mathrm{Spec}\ A/I$ of $X$ in $\mathrm{Spec}\ A$. Being homogenous, both $I$ and $f$ are contained in the ideal $(x_0,\dots x_n)$. By Krull's principal ideal theorem, every minimal prime ideal containing $f\mod I$ has codimension one. $X$ having dimension at least one implies that there are homogenous prime prime ideals $\mathfrak{q}\supsetneq \mathfrak{r}\supset I$. This implies that $(x_o,\dots x_n)$ has codimension at least two. Thus there are prime ideals containing $f\mod I$ that are contained in $(x_o,\dots x_n)$. However, I'd need to show that there are homogenous such prime ideals, right? I'd rather get hints than full solutions. Is it alright to use lowercase "i" or should you always use "I" (uppercase)? I often see "replace with" and "replace by" used interchangeably, but this doesn't sound right to me:     I replaced that component by this one.   I would use "with" in such a sentence. "By" only seems reasonable in passive, although "with" sounds like it would there work too:     That component was replaced by this one.   That component was replaced with this one.   In my native language, the equivalent of "replace by" can only be used in passive, and even then it's a bit weird unless a person is the object replacing something – perhaps this affects my judgment?  Web searches haven't come up with anything conclusive; the results are contradictory and speculative at best.  Are "replace with" and "replace by" interchangeable in active context? What about passive? Are there stylistic reasons to prefer one over the other? I know I'm asking for the close-to-impossible -- as a real full-backup certainly requires root permissions. But still there are many folks around not wanting to root their devices -- afraid of voiding their warranties or bricking their devices, or just not having their devices supported by any rooting method.  I also know there were a lot of questions asked already on this topic, and I checked all of them having the backup tag -- none covers the entire topic, all just have pieces, and especially people new to Android (but other non-power-users as well) would have a hard time figuring out the best way.  So I want a detailed canonical answer to the question:  Not involving root-solutions, how to achieve a backup as close as possible to a full backup?  Please do not give simple one-liner answers like "Use app xyz [full-stop]." If mentioning an app (and I doubt a single app would be the answer here), include what parts are covered by it -- as well as ideas on how to fill the gaps it leaves. (And to make it absolutely clear: I know the first thing coming to mind is Titanium Backup -- I use it myself, but this does not apply here: This question is strictly about methods for non-rooted devices!) Moreover, the answer should be as generic as possible in terms of applying to a wide range of devices (i.e. it should not be restricted to one device or manufacturer).  I already mentioned having investigated all questions here tagged backup. These will certainly be helpful providing details for answers here, so I will list up the topmost ones concerning my question:            All these provide some details for my question (so feel free to get inspired by them) -- but I feel there are still details missing. Also it would be helpful to have a summary -- say, an answer including the full description of "the maximum possible".  A last criterium: While I'd consider cloud-based solutions legit, I'd favour local solutions. If you can provide both: all the better. But some people value privacy quite high (I'm one of them), and thus would not trust their data to some cloud service.    Thanks to Ryan, we now have a solution for a really complete backup of all apps and their data -- which I didn't dare to hope for! The only disadvantage: His solution only works for less than 10% of all Android users; namely those whose devices are running at least with Android 4.x.  So again, I ask the close-to-impossible: Any solutions applicable at least on Gingerbread (2.3.x) or, better, even Froyo (2.2.x) -- so they cover the majority of current devices? These solutions may involve multiple tools (try to keep it as simple as possible though; think of your mother to follow your instructions ;)  And keep in mind: NO ROOT!    To further motivate high-quality answers (and hopefully avoid low-quality ones), I will be a harsh one here: As I rarely do, I will down-vote answers not fitting the mentioned criteria on one end -- but on the other end, I will setup a bounty for the best answer (which cannot be done immediately, but earliest after 2 days). Probability of asymmetric random walk returning to the origin Consider the random walk $S_n$ given by $ S_{n+1} =  \left\{   \begin{array}{l}     S_n+2 &amp; \text{with probability $p$}\\     S_n - 1 &amp; \text{with probability $1-p$}   \end{array} \right. \ $  Assume that $S_0 = n &gt;0 $. What is the probability of eventually reaching the the point $0$?  Seems that the probability for this must be less than one; since it is not symmetric, it is not guaranteed to reach the origin if $p&gt;0.5$. It also seems like the positive starting value not being at the origin matters too, but I'm not sure how to compute the probability of eventually reaching the origin. Count below a comment is misleading How does quantization solve the ultraviolet catastrophe? Progressive Draw 2 and Draw 4 Uno When playing with progressive Draw 2 and Draw 4 and (say that there are 2 players playing) and    Player 1 goes out with a Draw 2  Player 2 puts down a Draw 2    Does player 1 have to pick up 4 cards? Today after I installed Ubuntu 16.04 via USB on my pre-installed Windows 8 machine, I was required to restart my computer. After doing so I wasn't offered to select an OS, so after searching the internet, I came across Boot-Repair which I ran using the Try Ubuntu option in my Ubuntu installation USB. Following the boot repair I got a message saying,  If your computer directly reboots into Windows, try to change the boot order in your BIOS. If your BIOS does not allow to change the boot order, change the default boot entry of your Windows bootloader. For example, you can boot into Windows then type the following in an admin command prompt: bcdedit /set {bootmgr} path \EFI\ubuntu\shimx64.efi   After I rebooted my PC, I am receiving the following error message for about 3 seconds, after which it boots automatically into Windows 8, without letting me access Ubuntu. Error received while booting after manufacturer's logo, before grub: Failed to open \EFI\BOOT\grubx64.efi - Not Found   Failed to load image \EFI\BOOT\grubx64.efi: Not Found     start_image() returned Not Found    So I tried the other solution of typing that command in the cmd, to which my surprise, worked, and I am now prompted a window (grub) to choose my OS each time I turn on my PC, but unfortunately, I still receive an error each time, that lasts about 3s, after which I can choose my OS (both are working just fine) and work normally. Do you have any suggestions to get rid of the error message each time I boot my PC? Does the following limit exist? $$\lim_{x \to 0} x\sin\left(\frac{1}{x}\right)$$  If yes, then I have to find it; if no, then I need to give reason why. I couldn’t figure out how to prove this formally, can someone please help me out. The dimension of the Hilbert space is determined by the number of independent basis vectors. There is a infinite discrete energy eigenbasis $\{|n\rangle\}$ in the problem of particle in a box which can be used to expand a general state $|\psi\rangle$ as: $$|\psi\rangle=\sum\limits_{n=0}^{\infty} C_n |n\rangle$$ Here, the basis implies that the Hilbert space has countably infinite number of basis vectors. But one could well expand $|\psi\rangle$ in any other basis as well, say the continuous position basis. Then that superposition, $$|\psi\rangle=\int dx \psi(x)|x\rangle$$ is also possible. But this basis $\{|x\rangle\}$ is continuous and uncountably infinite. Such sets cannot be equal because they have different cardinality. Then my questions is how many independent basis vectors are really there in this Hilbert space? I was talking to a friend who owns a Mac. He has his set up so that when he swipes three fingers across his touchpad, it moves to the workspace in that direction. Is it possible to set this up in Ubuntu? Use bibliography numbers and citation from other file This question led to a new package:      I want to reference to citations from other file. Similar to what xr package does to labels, but I want to apply it for the bibliography.  If I'm able to do \cite{someone} in the main file, and it creates let say the number [4], I want to do the same \cite{someone} in a second file, and also create the same number [4]. Similar to what xr does with the labels.  By the way, I tried to add the main.bbl file from the main file. However, that adds all the references to the end of the second file. I want to avoid this.  Is there any package that accomplish this? Quote unquote (or end-quote), unseparated by the actual quotation I have two LED lamps in my corridor, and when I switch them off, they keep emitting light (not very strong, but it's annoying at night).  What can it be? How can I fix it? What is the difference between "I've been to China" and "I've gone to China"? Both are in the present perfect, but one uses the verb 'to go' and the other 'to be'. Is there a rule for this?  Is there any chance that the differences between "I have been" vs. "I have gone", are differences in English dialect (I don't know if this is the right word).  Edit Could I say that North American English speakers use "I have gone", and maybe U.K speakers say "I've been"? Or vice versa. Change rep required to downvote on MSE How many objects are being created? Why there isn't reputation points for successful flagging? By helping the site by flagging successfully (and therefore gaining higher flag weight), you typically inform that you are able to understand the system and be helpful.  Similarly, when you are helpful by editing posts (not necessarily even understanding anything, just making it better), you gain 2 points for each edit. Good flagging may require even more understanding; while editing just fixing spelling and/or formatting gives reputation points. You don't have to understand whether question (or answer) is on-topic, or even meaningful.  So, why there isn't for example 2 points for each flag that was acted on, in the same way flag weight increase is determined?