where is the change occurring if i am reassigning a character to *p .  #include&lt;stdio.h&gt; int main() {  char* p="hello" ; printf("%s",p); *p='a' ; printf("%s",p);  return 0;  }   *p='a' should have replaced 'h' with 'a' in the string .  *p should access and base element of the string pointed by p and replace it .  but print statement prints "hello " both times   but it doesnt can anyone explain why not ??
The following code receives seg fault on line 2:  char *str = "string"; str[0] = 'z';  // could be also written as *str = 'z' printf("%s\n", str);   While this works perfectly well:  char str[] = "string"; str[0] = 'z'; printf("%s\n", str);   Tested with MSVC and GCC.
What is exactly the density of a black hole and how can it be calculated? Can I prevent others from editing my question? edited my question,  where I specifically said that our software sending back stacktrace to one of our servers was a user-known public feature.  He then modified the title of my post, along with the entire content, making it sound like I snuck in the feature and that our application was phoning home without our users knowing.    I specifically wrote in the original post that the feature was not sneaky. He completely changed the meaning of my post. I find this to be rather unacceptable.  A few questions:   Is it possible to prevent editing of my posts? How can I retaliate? Can I file a complaint?   Can people with  do anything they want on Stack Overflow? I have my bachelors degree in engineering science: computer science, option electrotechnic. I have a good understanding of basic mechanics and dynamics, calculus (differential equations).  The books I'm now having a look at are:       What book do you recommend for studying fluid dynamics on my own and why? I am currently studying in class 10 and I am unable to do this problem. $$\tan 70 ° -\tan 20° -2 \tan 40° =4\tan 10°$$ Can anybody please help me.  Thanks! Do we really need reals? It seems to me that the set of all numbers really used by mathematics and physics is countable, because they are defined by means of a finite set of symbols and, eventually, by computable functions.  Since almost all real numbers are not computable, it seems that real numbers are a set too big and most of them are unnecessary.  So why do mathematicians love this plethoric set of numbers so much? No Indian (and Bengali) keyboard layout in Ubuntu 17.04? I've upgraded from Ubuntu 16.10 to 17.04 today. I'm from Bangladesh, and Bengali is my native language. There was an option to set keyboard layout to Bengali in all previous Ubuntu versions I've used. But there's no such option in 17.04, strangely. I can use Bengali by installing the package ibus-m17n,  so I thought maybe there was some problem during my upgrade. But then I checked my friend's PC which runs ubuntu 16.10 and found that ibus-m17n was not installed in 16.10 but there's option for Bengali keyboard layout. So is Bengali keyboard support really removed from 17.04, or was there a problem during my upgrade? When for the first time A new question I answer This haiku appears:     Little slab of meat   In a wash of clear jelly   Now I heat the pan   Such a message is Very strange; is anyone Seeing the same thing?  Have not seen again. Came and went like the wind does! Why I am so blessed? I have an Ubuntu 14.04 server that has no external monitor connected.  I use NoMachine to remote control the machine.  When I do so, the Unity/Gnome interface doesn't see any monitors connected, so I can only use 800x600 when connecting with NoMachine.  If I plug in a monitor, I can set the resolution to whatever size the NoMachine window is on the remote computer.  Is there a way to create a "fake" monitor device on Ubuntu so I can set a desktop resolution in Unity/Gnome? How do I see that $$f_{n+1}f_{n-1} = f_n^2 + (-1)^n$$ for $n \ge 2$, where $f_1 = 1$, $f_2 = 1$, and $f_{n+2} = f_{n+1} + f_n$ for $n \in \mathbb{N}$? I just upgraded to Ubuntu 18.04 but the UI did not change at all. For example I don't have the full screen app launcher; it's the same as it was back in 16 and 17. No notification center etc.   Do I need to somehow opt in? jsFiddle: no connection between html and js? Can't call simple function from button? Asymptotics of uniformly continuous functions over $\mathbb R$ Removing clock from the lock-screen I'm using Ubuntu 18.04.  I want to remove the digital clock from the lock screen because I just want to see a good wallpaper there, unobstructed.   How do I go about this? Is there a way to render an object with a subdivision surface modifier with a wireframe which is the original geometry as well as the wires that make the subdivision surface?  Example:   This wireframe here is curved. What if there was displayed the straight wireframe. The wires that make are made by the subdivision surface. Thats what I want to achieve. How to do it?  What I mean is - How to render the curved wireframe (which is the original geometry with the straight wireframe (which is the wireframe the is made by the subdivision surface)? How to add a small rounded rectangle around a word inline I want to add a box with a very light pink background and red border around a word but inline and  within a sentence.   i.e. something like this (drawn with inkscape)    I know the mdframed package can be used for placing boxes around paragraphs, but it does not seem to work inline and also give colored boxes.   Possibly TikZ is a solution? From the little I know of TikZ, it can be used to draw pictures inline inside a sentence. Which statistical test to analyse? I am trying to find out how inflammatory markers change in response to a mechanical device change. I have daily readings for the 5 days before the event and for the 5 days after the event. I am expecting a rise in inflammatory markers in the pre readings followed by a fall after the device change. I also need to find out how the change differs in two subgroups (sample sizes of the subgroups are n=21 and n=88). The aim is to find out if the change is significant, to consider these markers as predictors of the device failing and hence needing to be changed.    I would like to know what test would be appropriate to analyse this. I need to keep things simple as I and the people reading the results are non-statisticians. I have 4 servers with Debian Wheezy OS. I have Apticron installed that informs me about updates. Debian updates are realized so often that when I finish to update the last of 4 servers I get new email about new updates on the first server. I try to update all servers when I get a notification but I never know if there is a need to reboot the servers. I have read that if the directory "/var/run" contains file "reboot-required" I have to reboot the server. But I never have seen this file in "/var/run". How can I know when reboot is required? I don't want reboot my servers every time when I install new updates if it's not needed.  I understand that if I update PHP or MySQL, etc I don't need to reboot the server but updates usually contain many "lib...".  Below are 9 updates (I have received this week).  krb5-locales 1.10.1+dfsg-5+deb7u3 libdbus-1-3 1.6.8-1+deb7u6 libgssapi-krb5-2 1.10.1+dfsg-5+deb7u3 libk5crypto3 1.10.1+dfsg-5+deb7u3 libkrb5-3 1.10.1+dfsg-5+deb7u3 libkrb5support0 1.10.1+dfsg-5+deb7u3 libruby1.8 1.8.7.358-7.1+deb7u2 libxml2 2.8.0+dfsg1-7+wheezy3 ruby1.8 1.8.7.358-7.1+deb7u2   I have no idea what is "libkrb,libgssapi", etc. How can I detect if reboot is needed? Please do not suggest to install UnattendedUpgrades to let the servers update automatically because this can cause websites going offline if something updates not correct. What is the difference between a PDU and a power strip (both 120V, 15A)? I just chatted with an APC rep about upgrading the UPSes at our office. She recommended a single higher-capacity 6-outlet Smart-UPS to replace the four Back-UPS units we currently have. When I asked how she recommended plugging in all the current devices, she recommended using a APC's  PDU, but said not to use a power strip. At first she said I had to use an APC brand PDU, but after I inquired about using a Tripp-Lite PDU, she said any brand PDU would be fine.  The APC PDU previously referenced looks like a standard 120V power strip with overload protection but no surge protection. Other than overload protection (which seems redundant if plugging into the UPS), is there something else I'm missing, or should any power strip (without surge protection) be fine?  Edit: I didn't mention it earlier, but we don't have a proper rack--though I did still plan to mount the PDU or power strip to something. I guess I'm wondering if there's any special reason I should pay as much as $180 for the low-end APC PDU (which just looks like a power strip to me) vs. $20-$30 for a . How can I use wget to get files recursively if the username contains an @? Firstly my main goal is to try and get FTP files recursively in Centos.  However the actual FTP login contains an @ which ruins the syntax.  Is there some way to place the username in "double quotes" or some such equivalent such that I can use @in the username? I'm trying to create record Type selection screen in LWC, but getting this error  afterRender threw an error in 'c:createContact' [Cannot read property 'recordTypeInfos' of undefined]  HTML:  &lt;template&gt;     &lt;lightning-combobox name="recordType" label="Record Type" placeholder="Choose Status"                         value={value}                          options={recordTypeId}&gt;      &lt;/lightning-combobox&gt; &lt;/template&gt;   JS:  import { LightningElement, track, wire, api } from 'lwc'; import { getObjectInfo } from 'lightning/uiObjectInfoApi'; import CONTACT_OBJECT from '@salesforce/schema/Contact';  export default class CreateContact extends LightningElement {      @track statusOptions;     @track value;     @api objectApiName;      @track objectInfo;      @wire(getObjectInfo, { objectApiName: CONTACT_OBJECT,})     objectInfo;       get recordTypeId() {         // Returns a map of record type Ids          console.log(this.objectInfo);         const rtis = this.objectInfo.data.recordTypeInfos;         return rtis;     }  }