How to show directories before files in Finder? I would like to have windows in the Finder sort directories before files, in the manner of Microsoft Windows' Explorer as well as Linux KDE.  I tried following  but it did not yield the desired outcome, specifically some directories had contents sorted that way but some had files first then directories and some were still mixed.  Also, I would like to know what the difference is between sorting and arranging in the Show View Options screen.
How do you get Mac OS Finder to group folders together when sorting? I have Mac OS 10.7.4 and I'd like Finder to use "Is Folder?" as its first sort criteria, or in other words, group folders before files regardless of the sorting method.  Windows and Linux both do this by default.
Why is $ the default symbol for a user shell and # the default symbol for a root shell? Operating a standard bash shell on a server, the PS1 prompt defaults to ending in a $ for non-root users, and # for root.  IE:  ubuntu@server:~$ sudo su root@server:/home/ubuntu#   Why is this? Proving by induction that $1^3 + 2^3 + 3^3 + \ldots + n^3 = \left[\frac{n(n+1)}{2}\right]^2$ Need guidance on this proof by mathematical induction. I am new to this type of math and don't know how exactly to get started.   $$ 1^3  +  2^3  +  3^3  +  \ldots  +  n^3  =  \left[\frac{n(n+1)}{2}\right]^2 $$ How to validate an email address using a regular expression? Over the years I have slowly developed a  that validates MOST email addresses correctly, assuming they don't use an IP address as the server part.  I use it in several PHP programs, and it works most of the time.  However, from time to time I get contacted by someone that is having trouble with a site that uses it, and I end up having to make some adjustment (most recently I realized that I wasn't allowing 4-character TLDs).  What is the best regular expression you have or have seen for validating emails?  I've seen several solutions that use functions that use several shorter expressions, but I'd rather have one long complex expression in a simple function instead of several short expression in a more complex function. In Italian, when I write a sentence about an action (e.g. eating fish, playing), I would use the infinitive, such as  mangiare pesce fa bene alla salute (which literally is "to eat fish is healthy"), or giocare aiuta ad imparare (which literally is "to play helps to learn").   I would use the gerund in giocando si impara, but that would roughly mean "When playing, you learn." and in this case the infinitive would not be correct. (Giocare si impara is not what you would say in Italian.)  Should I use the infinitive, or the gerund, in sentences similar to the following ones?   To play with fire is dangerous. To win the lottery is just a matter of luck. To escape from Alcatraz is impossible. To practice makes you perfect.   Is the infinitive always wrong, when the verb is the subject of a sentence? Hazard Function - Survival Analysis I just started taking survival analysis class and I'm stumped on this question.  Let $T_1,...,T_n$ random independent continuous variables, with hazard function of $h_1(t),...,h_n(t)$. $T=min(T_1,...,T_n)$. And we need to show that the hazard function of T is $\sum_j{h_j(t)} $  Any help or direction are welcome :) I would like to see everything on my computer screen in grayscale (like say the kindle screen). How do I do this? Reverse / invert a dictionary mapping Given a dictionary like so:  my_map = {'a': 1, 'b': 2}   How can one invert this map to get:  inv_map = {1: 'a', 2: 'b'} In Unity, are there any pre-defined shortcuts, e.g. to open the dash or unhide the launcher? Adjective Used as an Adverb? That cake looks good.    In formal proper grammar, may good (adjective) get used as an adverb? Or, may you read it as, That cake (noun phrase, nominal[?], argument[?]), looks (verb, predicate[?]), good (subject compliment[?].? How may I discern this, grammatically? I have a group of objects of the same colour, consisting of compound paths, regular paths and groups of these. How to change the colour of all objects at once? When I tried to use colour picker or change it through color palette the colour remained the same but the graphics was rendered with a very tiny outline of the new colour, which I guess is not printable. Usually I had to change the colour of all objects individually.  Edit: I'm sorry if I was not too precise. I mean to apply new colour / swatch to all member objects of the group at once, not to change properties of a commonly shared swatch.    Edit 2: I received very useful answers, however my goal was to pick a colour from another object, serving as a source. When I tried to select all objects, for example with ctrl-a, and then use a eyedropper to pick up a desired colour, it didn't work for some objects in some groups. Please have a look at my answer where several methods are listed. How can I explain how to play D&D to new players without them falling asleep from boredom? Some of my friends just started playing Dungeons &amp; Dragons [5e] for the first time and don't know anything about how to play. I have tried explaining to them the things that are completely necessary and teach them the rest while playing but I could not get them to understand. None of them have a players handbook and they can't afford one and they really want to play. I really want a simple way to explain the basics and since I have a habit of explaining things in ways that are much too complicated. I have already told them the basic rules so all I need to know is a simple way to explain how to play. Is it consistent with ZF for there to exist a set $S$ such that the power set $P(S)$ is countable? If so, what is the weakest form of the axiom of choice needed to prove that no such set exists? How to implement an abstract class in ruby? I know there is no concept of abstract class in ruby. But if at all it needs to be implemented, how to go about it? I tried something like...  class A   def self.new     raise 'Doh! You are trying to write Java in Ruby!'   end end  class B &lt; A   ...   ... end   But when I try to instantiate B, it is internally going to call A.new which is going to raise the exception.  Also, modules cannot be instantiated but they cannot be inherited too. making the new method private will also not work. Any pointers? How to prove positive semidefiniteness of two matrices through Schur Complement? Let matrices $X$ and $Y$ be positive semideﬁnite. Show that $X \succeq Y \succ 0$ is equivalent to $Y^{-1} \succeq X^{-1}$.   The teacher tells me that it is easy to prove via the Schur complement. But I could not get his idea. Could anyone help me and give me some intructions? Thanks in advance! There's a web services I want to call in my application, I can use it with importing the WSDL or by just use "HTTP GET" with the URL and parameters, so I prefer the later because it's simple thing.  I know I can use indy idhttp.get, to do the job, but this is very simple thing and I don't want to add complex indy code to my application.  UPDATE: sorry if I was not clear, I meant by "not to add complex indy code", that I don't want add indy components for just this simple task, and prefer more lighter way for that. I've heard that you always want the same size of RAM (2x1GB sticks) but does their placement matter? I have four slots on my motherboard but does it matter if the sticks are not adjacent?  This particular question involves the If I run along the aisle of a bus traveling at (almost) the speed of light, can I travel faster than the speed of light? Let's say I fire a bus through space at (almost) the speed of light in vacuum. If I'm inside the bus (sitting on the back seat) and I run up the aisle of the bus toward the front, does that mean I'm traveling faster than the speed of light? (Relative to Earth that I just took off from.) Is every metric space a subspace of some connected metric space? Is every metric space a subspace of some connected metric space? If the space itself is connected then we're done, but if not then I think we can extend our metric space to make it connected.  I'm not sure whether this will work or not, but intuitively I think the answer is yes. "cron" processes spawning and piling up, but no crontab EDIT: I solved this, so see below for my own answer. While the bounty asks for a fix to the problem, I'd like to award it to someone who can explain why a cron process that ran for 6 years over multiple MacOS versions suddenly became a problem in Catalina.  First note, this is not a duplicate of  because I don't have active crontabs on my computer. Cron processes spawn, but they never finish, so they just keep piling up. I'm running MacOS Catalina 10.15.1  Cron jobs are spawning every couple of minutes and never dying. The oldest cron process always has a parent process "launchd", and I've searched for populated crontabs and can't find any. If I let this go on long enough, eventually I run into a scenario where I have hundreds of running cron processes and everything on my computer grinds to a halt, and I can't even open new apps (I get cryptic messages like ".app cannot be opened" when I try to open an app). My only solution at this point has been to keep activity monitor open and periodically killing off all active cron processes.  I've been able to create a new user account that seems to be immune from this issue. However, as soon as I logged into my apple ID on that account to set up iCloud drive, the problem started with that account, too. I logged out of my Apple ID and attempted uninstall iCloud drive, but the problem persisted. Clean installs of Catalina don't clear up the problem, I've reset SMC and PRAM multiple times, and repairing permissions (via this ). I've also ensured that cron has full disk access (via this ). I'm at a dead end with trying to troubleshoot this problem.  I'm not sure it's related, but my "system.log" file seems to get spammed the following few lines:  &lt;redacted&gt; AMPDeviceDiscoveryAgent[2132]: Entered:_AMMuxedDeviceDisconnected, mux-device:63 &lt;redacted&gt; AMPDeviceDiscoveryAgent[2132]: Entered:__thr_AMMuxedDeviceDisconnected, mux-device:63 &lt;redacted&gt; AMPDeviceDiscoveryAgent[2132]: tid:9a27 - Mux ID not found in mapping dictionary   ANY help is appreciated. In a moment of cheapness, I decided not to order a 5v to 3.3v level shifter from Sparkfun, but instead to put it together myself.  The  used a  MOSFET, but since I enjoy surface-mount soldering about as much as root canal treatment, I decided to use a  that is through-hole mounted and easily available from my preferred supplier.  The results of this were sub-optimal.  When pulling the 5v line to ground, all was fine - the 3.3v side went to 0.07v.  But when pulling the 3.3v to ground, the 5v line showed around 4.14v (it was otherwise a touch above 5.1v).  On a closer reading of the datasheets involved, as well as the original Philips application note on the subject, I began to come to the conclusion that the gate threshold voltage was the problem.  By altering the schematic and tying the MOSFET's gate to 5v instead of 3.3v, both sides seem to work fine.  Pulling either side low causes the other side to go low.  I'm not, however, at all confident that this is actually a sane thing to do.  My understanding of the original schematic isn't deep enough to form a sensible opinion.  Will this modified schematic work, or are the current good results I'm seeing mere fluke or a precursor to something releasing magic smoke?