I would like to save more chars in ch[500] then it is already there. I dont want to lose the chars I've saved there before.  Something that would work like this:  ch = ch + ’nextch’;
I'm working in C, and I have to concatenate a few things.  Right now I have this:  message = strcat("TEXT ", var);  message2 = strcat(strcat("TEXT ", foo), strcat(" TEXT ", bar));   Now if you have experience in C I'm sure you realize that this gives you a segmentation fault when you try to run it. So how do I work around that?
Inverse of this $3\times 3$ matrix using the Cayley–Hamilton theorem Find the inverse of the matrix $$\begin{pmatrix} -1 &amp; 2&amp; 0 \\ 1&amp; 1 &amp;0 \\ 2 &amp; -1&amp; 2 \end{pmatrix}$$ using the Cayley–Hamilton theorem.  Thanks! Question:   Prove that a norm is always non-negative.   Assume that the norm is negative.   Define: $f: \mathbb{R}^{n}\rightarrow \mathbb{R}^{-}_{0}$  $v \mapsto \left ( \vec{v} \right )f=\left \| \vec{v} \right \|$  $\left ( \vec{u}+\vec{v} \right )f=\left \| \vec{u}+\vec{v} \right \| \in \mathbb{R}^{-}_{0}$ and  $\left ( \vec{u} \right )f=\left \| \vec{u} \right \|,\left ( \vec{v} \right )f=\left \| \vec{v} \right \|=\left \| \vec{v} \right \| \in \mathbb{R}^{-}_{0}$  At this point I am unable to progress further.  Any help is appreciated. How should I act when I see tiny "Have you tried this..?" type of answers? When should I use a unique constraint instead of a unique index? When I want a column to have distinct values, I can either use a constraint  create table t1( id int primary key, code varchar(10) unique NULL ); go   or I can use a unique index  create table t2( id int primary key, code varchar(10) NULL ); go  create unique index I_t2 on t2(code);   Columns with unique constraints seem to be good candidates for unique indexes.  Are there any known reasons to use unique constraints and not to use unique indexes instead? Schengen visa application rejected because my US visa stamp expires in December. What are my options? I went to the Italian consulate in Washington, DC today and they would not accept my visa application because they said my US visa stamp cannot expire less than 3 months after the end of my trip to Italy. Here's my relevant visa and trip info:   US visa stamp expires on 16 Dec 2015 I-797 valid until 3 Mar 2017 Trip to Italy is from 15 Oct to 25 Oct 2015   Is it true that my visa stamp needs to be valid for 3 months after my trip, even though I can legally stay in the US until 2017? Does anyone have any suggestions for getting a Schengen visa in my situation? 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? Someone wants to send me cash by DHL. How's this scam supposed to work? This raises a bunch of red flags (also confirmed by googling the email address it came from), but I don't quite understand how this scam is actually supposed to work. So, here it goes:   I put up an ad (for a guitar, 90€) on LeBonCoin (the French equivalent of Craigslist). Someone contacts me by text message (anonymous with no actual phone number), saying they want to continue by email. I then get an email, with roughly the following content (rough translation):     OK, I will buy it, but I need to send you cash by "express DHL letter". The DHL driver will pick up the item when he gives you the cash. I need the following information: full name, postal address, price of the item, and your phone number.    I'm guessing that this works by them requesting some "delivery fee" in advance, but does anyone know how this actually works? I want to click on file to inherit the name for the file being saved. I can't read file names in the dialog box because the color is too faint. This is the same question as   That question does not have an answer but I don't have enough points to interact there so I have to post a new question.    Edited to add screen shots I tried to calibrate the monitor which no effect and did not change the readability of "unavailable" file names. I have added screenshots of previous operating systems to compare: Please tell me how Mojave is not to blame here: Is the C# "explicit implementation" of the interface present in Java? In C#, if you have two base interfaces with the same method (say, F()) you can use explicit implementation to perform different impl. for F(). This alloes you to differently treat the object, corresponding to the current point of view: as IMyInterface1 or IMyInterface2. Is this possible in Java? How do I kill processes in Ubuntu? How do I kill all processes running by my own non-root account?  I have some spinning smbd  processes that I caused from my windows machine and so I telnetted into the linux server and I want to kill those spinning processes.   I don't have authority to restart services or reboot the machine. Identify which OrgWideEmailAddress records are valid for current user I'd like to create a popup list on one of my Visualforce pages, for a user to select from a list of OrgWideEmailAddress records.  My goal is to limit the list to only those records that they're allowed to use.  I'm going to save the selection for use in later automatic emails.  Based on what I've read, I won't be able to send emails to certain OrgWideEmailAddresses:   The address hasn't been verified yet.  I don't see any fields in the schema that appear to show verification state. The address is only available to profiles that the user isn't a member of.  I don't see where the profile list is stored for each record.   Some of my problem could just be due to not understanding the standard objects so well, and perhaps there's a way to get at this through UserInfo, or by making my query on the User object which may have a child relationship to OrgWideEmailAddress since it's listed in the schema viewer of the Force.com IDE.  Here's the test code I'm working with:  for (OrgWideEmailAddress addr : [SELECT DisplayName, Address          FROM OrgWideEmailAddress ORDER BY DisplayName]) {     System.debug( addr.DisplayName + ' &lt;' + addr.Address + '&gt;'); }   I tried creating a new Messaging.SingleEmailMessage and then calling setOrgWideEmailAddressId() on it with each OrgWideEmailAddress Id, in hopes that invalid Ids would throw an exception, but to no avail.  My goal is to modify the test code to provide just the subset of records that the current user will be able to use. So I need to find the Convergence Radius and Convergence Domain of the complex power series: $\sum\limits_{n=0}^\infty \frac{1}{2^{n}} z^{2^n}$  I've tried looking at the individual parts of the series and rewriting it somehow but couldn't find a way.  It can probably be solved, after a step or two, by the formula $R=\frac{1}{\displaystyle\limsup_{n\rightarrow \infty}\sqrt[n]{|a_n|}}$ .  Thanks. This was working perfectly on 17.10 but after upgrading to 18.04 yesterday, when the lid is closed the screen turns off but doesn't suspend properly.  I travel around a lot and immediately noticed the heat (and battery draining) when taking it out of the travel case.  I've tried uncommenting these lines in /etc/systemd/logind.conf  HandleLidSwitch=suspend HandleLidSwitchDocked=suspend   and restarted but didn't make any difference. Casting a function pointer to another type Let's say I have a function that accepts a void (*)(void*) function pointer for use as a callback:  void do_stuff(void (*callback_fp)(void*), void* callback_arg);   Now, if I have a function like this:  void my_callback_function(struct my_struct* arg);   Can I do this safely?  do_stuff((void (*)(void*)) &amp;my_callback_function, NULL);   I've looked at  and I've looked at some C standards which say you can cast to 'compatible function pointers', but I cannot find a definition of what 'compatible function pointer' means. Where are the outliner toggles in 2.8? The selection toggle arrows in the Outliner disappeared. Is there some preference in the settings that has to be turned on? Finding Distribution function from probability density function How do I assign a value to a whole array of integers? Saying that refers to not going overboard in solving a problem when a simple solution exists So I know I've heard this saying in American English before but I just can't quite find the original.  I have come up with several made up variations like:   I don't send the Navy (or whole army, or a battalion) when all you need is a diplomat. Don't buy the whole cow when all you need is milk.   What's the more commonly heard saying/phrase for this of expression? Best Practice for Forcing Garbage Collection in C# Howto wildcard SELECT * to query all fields of objects in APEX? I have created sObject and I need all the fields and I have many. Is there a way I can directly get all of them rather then typing each one of them.