How can I remove the first letter from  a directory name? for example: Folder is named as "AFolder_01" how can I rename it to "Folder_01"  The reason for my question is that I have list of folders and I want to rename all these folders at once by removing the first letter. I found this code online to remove the last character(s):    while IFS= read -r dir; do [[ -d $dir ]] &amp;&amp; mv -i "$dir" "${dir%?}"; done &lt;all.txt    How can this code be revised to remove the first letter? i.e. In my example  rename "AFolder_01" to "Folder_01" How can this code be revised to add charterer back at the beginning of the folder name: i.e. in my example rename "Folder_01"  to "AFolder_01"
I have a bunch of files as follows:  04602635_b0294.DAT20120807164534 04602637_b0297.DAT20120807164713 04602638_b0296.DAT20120807164637 04602639_b0299.DAT20120807164819 04602640_b0298.DAT20120807164748 04602641_b0300.DAT20120807164849 04602650_b0301.DAT20120807164921 04602652_b0302.DAT20120807164956   I need to rename them to exclude the prefix. It needs to look like this..  b0294.DAT20120807164534 b0297.DAT20120807164713 b0296.DAT20120807164637 b0299.DAT20120807164819 b0298.DAT20120807164748 b0300.DAT20120807164849 b0301.DAT20120807164921 b0302.DAT20120807164956   EDIT  I forgot to add that I am using Solaris.
How to derive addition of velocities without the Lorentz transformation? Lorentz contraction and time dilatation can be deduced without Lorentz transformation. Can you deduce also the theorem of    $$w~=~\dfrac{u+v}{1+uv/c^2}$$   without Lorentz transformation? Using just the constancy of light speed. Short story with space microbes latching onto electromagnetic fields This is a sci-fi story set on Earth. From the depths of space comes these microbes that latch onto electromagnetic fields. Anything electronic is rendered useless. There's the usual stuff where governments try to solve the issue but make it ultimately worse. It's only when they realise that the microbes surround the planet that they realise it is futile. The story closes with people having returned to a simpler life, using medieval farming methods, not using electricity in any form, getting about by horse, etc. I think it was a short story. Why (in relatively non-technical terms) are Calabi-Yau manifolds favored for compactified dimensions in string theory? What's the best way to communicate between view controllers? Being new to objective-c, cocoa, and iPhone dev in general, I have a strong desire to get the most out of the language and the frameworks.  One of the resources I'm using is Stanford's CS193P class notes that they have left on the web.  It includes lecture notes, assignments and sample code, and since the course was given by Apple dev's, I definitely consider it to be "from the horse's mouth".  Class Website:   Lecture 08 is related to an assignment to build a UINavigationController based app that has multiple UIViewControllers pushed onto the UINavigationController stack.  That's how the UINavigationController works.  That's logical.  However, there are some stern warnings in the slide about communicating between your UIViewControllers.  I'm going to quote from this serious of slides:   Page 16/51:     How Not To Share Data         Global Variables or singletons         This includes your application delegate      Direct dependencies make your code less reusable         And more difficult to debug &amp; test         Ok.  I'm down with that.  Don't blindly toss all your methods that will be used for communicating between the viewcontroller into your app delegate and reference the viewcontroller instances in the app delegate methods.  Fair 'nuff.  A bit further on, we get this slide telling us what we should do.  Page 18/51:     Best Practices for Data Flow         Figure out exactly what needs to be communicated   Define input parameters for your view controller   For communicating back up the hierarchy, use loose coupling         Define a generic interface for observers (like delegation)         This slide is then followed by what appears to be a place holder slide where the lecturer then apparently demonstrates the best practices using an example with the UIImagePickerController.  I wish the videos were available! :(  Ok, so... I'm afraid my objc-fu is not so strong.  I'm also a bit confused by the final line in the above quote.  I've been doing my fair share of googling about this and I found what appears to be a decent article talking about the various methods of Observing/Notification techniques:   Method #5 even indicates delegates as an method!  Except.... objects can only set one delegate at a time.  So when I have multiple viewcontroller communication, what am I to do?  Ok, that's the set up gang.  I know I can easily do my communication methods in the app delegate by reference's the multiple viewcontroller instances in my appdelegate but I want to do this sort of thing the right way.  Please help me "do the right thing" by answering the following questions:   When I am trying to push a new viewcontroller on the UINavigationController stack, who should be doing this push.  Which class/file in my code is the correct place? When I want to affect some piece of data (value of an iVar) in one of my UIViewControllers when I am in a different UIViewController, what is the "right" way to do this? Give that we can only have one delegate set at a time in an object, what would the implementation look like for when the lecturer says "Define a generic interface for observers (like delegation)".  A pseudocode example would be awfully helpful here if possible. Is it normal for a fast prime to exhibit purple fringing in middle of the image? I have just bought a Nikon 50mm f/1.8D prime lens.  I took this picture (leg of my glasses frame on a mouse, and a LED desk lamp is on top of it) : f1.8, 1/80s, ISO 200   The purple fringing is right in the middle of the picture. Does it happen very often to this lens? Help Me Understand My Bicycle's Gears How can I prove the Carmichael theorem I am trying to prove that these two definitions of Carmichael function are equivalent.  I am using this definition of Carmichael function:     $\lambda(n)$ is the smallest integer  such that $k^{\lambda(n)}\equiv1 \pmod n\,$ $\forall  k$ such that $\gcd(k,n)=1$.   to prove this one:     $\lambda(n) = \begin{cases}\phi(p^a) &amp; (p=2\text{ and }a\le 2)\text{ or }(p\ge 3)\\\dfrac 1 2 \phi{(2^a)}  &amp; a\ge 3\\ \text{lcm}\left((\lambda(p_1^{a_1}),\cdots,\lambda(p_k^{a_k})\right)&amp; \text{for }n=\prod_{i=1}^k p_i^{a_i} \end{cases}$   Since $a^{\lambda(n)}\equiv 1 \pmod n$,  and $a^{\lambda(m)}\equiv1 \pmod m$ with $\gcd(m,n)=1 \implies a^{\text{lcm}({\lambda(n)},\lambda(m)}\equiv1 \pmod {nm} $   Hence $\lambda (mn)=\text{lcm}(\lambda(n), \lambda(n))$ for $m$ and $n$ coprime to each other.  How can I prove the other relations? How to output HTML from JSP  block? I just started learning JSP technology, and came across a wall.  How do you output HTML from a method in &lt;%! ... %> JSP declaration block?  This doesn't work:  &lt;%!  void someOutput() {     out.println("Some Output"); } %&gt; ... &lt;% someOutput(); %&gt;   Server says there's no &ldquo;out&rdquo;.  U: I do know how to rewrite code with this method returning a string, but is there a way to do this inside &lt;%! void () {  } %> ? Though it may be non-optimal, it's still interesting. Can "real" be used as an adverb to describe an adjective? I want every new user from now on to have bash as their shell by default.    I know that to change your own shell to bash, you would use the command "chsh -s /bin/bash", but how do I automatically set all future users' shell to bash by default? How to use Font as a variable? How to negate a specific symbol? I want to negate the symbol whose code is \models (this would be specific to Formal Logic). How can I do that? I tried a number of combination, but didn't find how this could be done. I tried \neqmodels, \nemodels, \notmodels, \nmodels  but all of them are wrong.  Is there a general way to negate symbols? The computed moments of log normal distribution can be found . How to compute them? I know questions on the "hot" tab of a site homepage are based on some sort of views/velocity criteria, but does anyone know the actual algorithm used?  Background: I was considering a feature-request about the "hot" tab, but I don't have enough information to speak about it intelligently. Much less than, what does that mean? What exactly does $\ll$ mean?  I am familiar that this symbol means much less than.   ...but what exactly does "much less than" mean? (Or the corollary, $\gg$)  On , the example they use is that $1\ll 9999999999$ But my thought on that is that $10^{10^{10^{11}}}\ll 10^{10^{10^{11}}}+9999999999$, based on the same logic. But I am confused because the numbers are comparitively.   Logically, I am really kinda spent dealing with this issue of mine. Thanks for any input. What is difference between int.class and Integer.TYPE in java? In my Master thesis, I would like to have the title page without any page number and an acknowledgments section and the table of contents with roman numbers. The rest of the document should be numbered arabic.  I have tried this, to have roman numbers for the Table of contents and normal numbers for the rest.  \documentclass[12pt,ngerman,openany]{report} \usepackage{titlesec} \usepackage{titletoc} \usepackage{cite} \usepackage[a4paper]{geometry} %\usepackage[T1]{fontenc} \usepackage[utf8]{inputenc} \usepackage[ngerman]{babel} %\usepackage{ngerman}{babel} \usepackage[T1]{fontenc} \usepackage{graphicx} \usepackage{float} \selectlanguage{ngerman} \usepackage{amssymb} \usepackage{amsmath} \usepackage{url} \usepackage{epstopdf} \usepackage{scrhack} \usepackage{listings} \usepackage{caption} \titleformat{\chapter}{\rmfamily\huge}{\textbf\thechapter.}{25pt}{\huge\textbf} \defcaptionname{ngerman}{\lstlistingname}{Code} \defcaptionname{ngerman}{\lstlistlistingname }{Codeverzeichnis}  \lstloadlanguages{R}  \lstset{% general command to set parameter(s)    basicstyle=\sffamily\footnotesize, % print whole listing small    keywordstyle=\sffamily\footnotesize\bfseries, % ubold black keywords    identifierstyle=, % nothing happens    commentstyle=\sffamily\footnotesize\slshape, % green comments    stringstyle=\sffamily\footnotesize, % typewriter type for strings    showstringspaces=false, % no special string spaces    numbers=left,    numberstyle=\sffamily\footnotesize,    stepnumber=1,    numbersep=10pt,    showspaces=false,    showtabs=false,    frame=lines,    morecomment=[l]{\%},    float=htbp,    numberbychapter=true  }   \begin{document} \let\cleardoublepage\clearpage   \pagenumbering{roman}  \tableofcontents  \clearpage  \vspace*{75mm} \chapter{Einleitung} \section{Motivation} bla bla bla \section{Ziel}  bla bla \chapter{Stand der Technik zur Mustererkennung} \section{Die Zeitreihen} bla bla \subsection{Beschreibung} bla bla \subsection{Erklärung}  bla bla  \subsection{Vorhersage} bla bla \subsection{Kontrolle} bla bla \section{Feature Extraktion} bla bla \subsection{Autokorrelation} \subsection{Was ist Autokorrelation?} bla bla   \subsection{Autokorrelation und Zeitreihen} bla bla  \subsubsection{Zeitreihe-Diagramm}  bla bla \subsubsection{Lagged Streudiagramm} bla bla  \subsubsection{Autocorrelation-Function (Korrelogramm)} bla bla \subsection{Spektralanalyse} \subsection{Was ist Spektral-Analyse} bla bla \end{document} How to disable autorefresh in snap Is it possible to disable autorefresh in snap? This  says that Snaps are updated automatically in the background to the latest version, every day. Some snaps (e.g. vlc) are built daily, and it makes no sense to install them every day. In the Avengers movie, why is Loki sweating and weak when he first arrives on Earth, in the SHIELD base? I am hearing my screen