install mono on ubuntu server 18.04
How can I compile, run and decompile C# code in Ubuntu terminal?
"No such file or directory" when trying to remove a file, but the file exists? I am trying to remove a png image that was uploaded to my server via a PHP script. Whenever I try to delete it both through ftp and terminal, I get the error   No such file or directory   However, when I ls in the dir, the file is listed and it is also listed in my ftp client. I have tried creating a file with the same name and I end up getting two files with the same name.   I can open the file that supposedly does not exist, but I still can't remove it. I have also tried rebooting my server. Any ideas what may be the issue? I am running a 64 bit version of Ubuntu, but I don't think its a 32/64 bit issue. I should also note I have removed many other png files uploaded by the same PHP script.  Output for ls -l  total 224  -rw-r--r-- 1 www-data www-data 222838 May 13 04:14 qyxdshyikfr_fishing_timeout.png  -rw-r--r-- 1 root root 272 May 14 06:54 upload.php   Output when trying to rm  rm: cannot remove ‘qyxdshyikfr_fishing_timeout.png’: No such file or directory   upload.php: When should I make explicit use of the `this` pointer? How can we discipline a strong-willed, misbehaving 5 year-old? My 5 year old son receives and fears punishment but repeatedly exhibits the same unacceptable behaviors.  He's always been strong-willed, and is usually the kind to view a statement like "Don't do that" as an open invitation to do it.  We've tried redirection or distraction tactics, but he is still so narrowly focused on doing the original behavior.  Even worse, he will typically do the prohibited behavior and flagrantly tell us or show us that he's done it.  Repeatedly, even after punishment.  (He's in time out right now for this very thing).  He's consistently punished, yet he continues down the same self-destructive path each time.  When he is punished, we explain what he did wrong, why he's being punished, and why he shouldn't do what he was told not to do.  Sometimes he'll even tell us first why he's in trouble, so it makes me wonder if he's acting out for the inevitable negative attention he gets.  I think he gets plenty of love and positive attention- he's an only child and stays with a relative during the day.  We're trying to give him a good, fun childhood, but we need to figure out how to effectively discipline him.    His repeated misbehavior includes:   Yelling at the top of his lungs in public (stores, friends' houses, etc) Running away from us (at parks, stores, parking lots, etc) Talking back and disrespecting authority figures Hurting animals even after we explain why it's wrong Repetitive nuisance behaviors (repeating himself, banging his fists, kicking walls, intentionally crumbling food on floors, etc) Repeatedly asking us why he can't do something even after it's been explained to him Basically, most bad behaviors that young children may do, but repeated over and over again, even after discipline   He gets a warning to stop the behavior, then depending on the severity of what he's done (and where we are), he'll either go to time out or lose a privilege (such as taking away a favorite movie or missing out on an activity).  Going to time outs and losing privileges really upset him, but still do not ultimately deter him from the bad behavior.  It's like he can't help himself.  My spouse and I are getting worn down.  We try to model good behavior and encourage him to be well-mannered and respectful.  This behavior mortifies us.  It seems we can't even enjoy life as a family because our son is so disruptive and unresponsive.  Most public outings have to be cut short or eliminated because he consistently misbehaves and doesn't respond to our discipline.  After he's misbehaved, when we try to have heart-to-heart talks with him about his behavior and why we expect him to mind us, he usually has a little trouble expressing himself, and a lot of times we get the same nonsensical responses from him (Us: Why did you do [bad behavior]?  Him: Because I didn't want to).  He also doesn't like to make eye contact.  We don't usually feel like we've gotten through to him.  Is there another discipline tactic we could try?  Or does it sound like we need to see a professional at this point?  We're at a loss, and don't want things to spiral further out of control as he gets older (and even begins school).  We just want him to understand that his behavior isn't always acceptable.  Thanks for reading.  Update (from comments below): My spouse and I disagree on spanking, as we had different experiences with it. He feels it's necessary sometimes. Since our son failed to improve after time outs and taking away items/privileges, I grew to agree with him and we used it for select bad behaviors. It didn't work any better. However, when he was spanked, he was always told why. I didn't mention that we have used it because I was afraid it would distract from the original question, but since it has already come up [in comments], yes, it has been explored, but with no better results than our other tactics. How to typeset subscript in usual text mode? Gravitational potential at a point in a gravitational field is defined as work done per unit mass in bringing a small test mass from infinity to the point.  I know that:   By integration, we find that gravitation potential is negative. The maximum value of gravitational potential which is at infinity distance is 0, therefore minimum value should be negative.   But, what I do not understand is force is in the same direction as displacement so why work done is not positive? Windows 10 Search not loading, showing blank window How to run an encrypted virtual machine? How does ${!#} work in bash to get the last command-line argument? From the Advanced Bash-Scripting Guide, to get the last command-line argument:     Or: lastarg=${!#}    This is an   indirect reference to the $# variable.    Note that lastarg=${!$#} doesn't work. Let's say I use a  with a lot of code inside. To improve readability and reusability I'd like to use helper/private methods. However, a Drupal .module file is not a class.  The idea is to split big methods from this file into more readable and reusable smaller methods.  What is the correct way to call helper/private methods from a Drupal .module file? Nothing shows up in the terminal when I type my password When I'm about to install a program in the terminal it wants the password:  [sudo] password for xxx:   But when I start to type my password nothing happens. What should I do? The Wikipedia page () proves that $$f(x) = \begin{cases}  \exp(-1/x),  &amp; \mbox{if }x&gt;0 \\ 0, &amp; \mbox{if }x\le0 \end{cases}$$ is a non-analytic smooth function. But I don't understand why the fact that "the Taylor series of $f$ at the origin converges everywhere [where does "everywhere" mean here?] to $0$" implies the Taylor series converges to $0$ when $x&gt;0$? Can someone explain this in greater detail? I guess there should be a gap in my understanding of power series. For what powers $k$ is the polynomial $n^k-1$ divisible by $(n-1)^2$? I'm trying to execute a string into my bash script. String contains variables (so I could substitute some CLI arguments depending on circumstances).  The problem is when I use variable containing --argument=value, everything breaks up, giving error:  Missing trailing-' in remote-shell command.   Example code:  #!/bin/bash  rsync_path="/usr/bin/rsync -azhrP" rsync_ssh_cmd="--rsh='ssh -o Compression=no'"  `$rsync_path /path/to/file $rsync_ssh_cmd username@localhost:/tmp`   If I just echo the last string from this code, it looks fine. But if i try to execute this string from script, it doesn't executes as expected.  I found a workaround - everything became OK if I try  eval "my-command-string"   instead of  `my-command-string`   or  (my-command-string)   Why does it so? How could I (should I really?) avoid to use eval?  I use bash 4.3.11(1)-release (x86_64-pc-linux-gnu) (Kubuntu 14.04.3). How can I add reflection to a C++ application? I'd like to be able to introspect a C++ class for its name, contents (i.e. members and their types) etc. I'm talking native C++ here, not managed C++, which has reflection. I realise C++ supplies some limited information using RTTI. Which additional libraries (or other techniques) could supply this information? Node access based on view mode I need to customize the UI for a group of users at another office.  I want to turn off a bunch of toolbars and menus that are not needed.  I know how to save my configurations (Settings -> Customization...) to a INI file.    How do I setup the other users computers to load the INI at startup?   I am using Windows 7 and Qgis 2.0.1. Integrity constraints in a relational database - should we overlook them? I’m in a permanent discussion with the developers of the company where I work because they say it is better to get rid of relationship enforcement (via FOREIGN KEY constraint definitions) in a relational database in order to speed up large queries and to gain better performance. The platform under consideration is MySQL 5.x, and no FOREIGN KEY has been set up, even some PRIMARY KEY constraints of the relevant tables are missing which, at least for me, is not reasonable. Maybe they’re right and I’m wrong, but I don’t have enough arguments to discuss about this situation. This has been the preferred approach for three years now. I’m new in this company (only one month) but, as the product “works”, there is hesitation to enhance the database; nevertheles, the first thing I noticed is one page taking 1 minute to load (yes, 60 seconds!). One of the claims behind the current state of affairs is that a “denormalized” database is faster than a normalized one, but I don’t believe that’s true. Most of the relevant queries include JOIN operations, which makes them run very, very, very slow with large amounts of data (the database contains millions of rows). Commonly, the handling of “CRUD” operations is implemented at the application program code level; for example, in order to DELETE some data FROM, let’s say, TableA:  it is necessary to first check on the fly if there is some relationship between the rows of TableA and TableB, in case that said relationship is “detected”, then the app program code won’t allow to DELETE the pertinent row(s), but if for some reason the app program code fails, then the DELETE operation will “succeed”, no matter if there is any relationship regarding the involved rows and tables.  Question Could you help me to elaborate a good, accurate and solid answer to enrich the debate?  Note: Maybe something like this has been asked (and answered) before, but I couldn’t find anything by means of Google. adding hours in date time format java Can the rogue repeatedly hide in combat to sneak attack the same enemy? One of my players is a rogue and has been, on his turn, using Cunning Action to hide as a bonus action and immediately afterwards attacking. I have been ruling that this does work to grant him advantage as an unseen attacker as I believe that is the RAW, but it seems a little strange. Is he really, in the span of 6 seconds, ducking behind a corner and popping back out and this completely disorientates his target? I guess I just wanted to make sure I was ruling correctly. Further customize color of hyperref links I have tried to find a way to customize how internal links are colored, but I don't yet have the expertise in finding and redefining commands. In the LaTeX example below, I describe how I would like to change the colors of various links. Any ideas or examples are much appreciated.  \documentclass{article}  \usepackage[backref=true]{biblatex} \begin{filecontents}{refs.bib} @book{cit1, title = {The backreferences should be yellow}, author = {Last, First} } \end{filecontents} \bibliography{refs.bib}  \usepackage{color} \usepackage[usenames,dvipsnames,svgnames,table]{xcolor} \usepackage[colorlinks=true,             linkcolor=red,             urlcolor=blue,             citecolor=gray]{hyperref}  \begin{document}  \title{Title} \maketitle \tableofcontents \listoffigures  \section{Table of content's links should be green} \label{s1} All text, captions, and section headers after the list of figures should be black. The citation links should be gray.\autocite{cit1} \subsection{Table of content's subsections links should be orange} Internal links like this section link \ref{s1}  or this figure link \ref{f1} should be blue.  \begin{figure}[h] \caption{List of figures links red} \label{f1} \end{figure}  \printbibliography  \end{document}