could not exec dpkg! e: sub-process /usr/bin/dpkg returned an error code (100) - I cant fix it
Lost/Deleted dpkg (package manager for Debian). How do I get it back?
What does a binomial coefficient with commas mean? I'm reading through  paper (on Dyck Paths). Near the middle of the second page, the author states the following:     Remark For the set $h_n$ there are ${k\choose t_1, t_2, ... , t_m }$ $n + k \choose{k}$ $=$ $ n + k\choose {n, t_1, t_2, ..., t_m}$ different Dyck paths.   What does ${k\choose t_1, t_2, ... , t_m }$ mean? I know what the binomial coefficient is, but I'm not sure how to interpret it when one of the parameters is a set. What else do I need to produce two dots above o? How can I deduce/identify an app from a notification icon? How to fix Permission Denied (Public key) error? While trying to communicate between my desktop Ubuntu 12.10 and Fedora 19 desktop, I am facing the error of Permission Denied (Public key). I am able to login through ssh from fedora to Ubuntu, but not vice-versa. I even performed telnet on both machines via port 22 and both machines are listening, but not through ssh. What to do? Any idea?  My sshd_config file is as follows:  # Package generated configuration file # See the sshd_config(5) manpage for details  # What ports, IPs and protocols we listen for Port 22 # Use these options to restrict which interfaces/protocols sshd will bind to #ListenAddress :: #ListenAddress 0.0.0.0 Protocol 2 # HostKeys for protocol version 2 HostKey /etc/ssh/ssh_host_rsa_key HostKey /etc/ssh/ssh_host_dsa_key HostKey /etc/ssh/ssh_host_ecdsa_key #Privilege Separation is turned on for security UsePrivilegeSeparation yes  # Lifetime and size of ephemeral version 1 server key KeyRegenerationInterval 3600 ServerKeyBits 768  # Logging SyslogFacility AUTH LogLevel INFO  # Authentication: LoginGraceTime 120 PermitRootLogin yes StrictModes yes  RSAAuthentication yes PubkeyAuthentication yes #AuthorizedKeysFile    %h/.ssh/authorized_keys  # Don't read the user's ~/.rhosts and ~/.shosts files IgnoreRhosts yes # For this to work you will also need host keys in /etc/ssh_known_hosts RhostsRSAAuthentication no # similar for protocol version 2 HostbasedAuthentication no # Uncomment if you don't trust ~/.ssh/known_hosts for RhostsRSAAuthentication #IgnoreUserKnownHosts yes  # To enable empty passwords, change to yes (NOT RECOMMENDED) PermitEmptyPasswords no  # Change to yes to enable challenge-response passwords (beware issues with # some PAM modules and threads) ChallengeResponseAuthentication no  # Change to no to disable tunnelled clear text passwords PasswordAuthentication yes  # Kerberos options #KerberosAuthentication no #KerberosGetAFSToken no #KerberosOrLocalPasswd yes #KerberosTicketCleanup yes  # GSSAPI options GSSAPIAuthentication no GSSAPICleanupCredentials yes  X11Forwarding yes X11DisplayOffset 10 PrintMotd no PrintLastLog yes TCPKeepAlive yes #UseLogin no  #MaxStartups 10:30:60 #Banner /etc/issue.net  # Allow client to pass locale environment variables AcceptEnv LANG LC_*  Subsystem sftp /usr/lib/openssh/sftp-server  # Set this to 'yes' to enable PAM authentication, account processing, # and session processing. If this is enabled, PAM authentication will # be allowed through the ChallengeResponseAuthentication and # PasswordAuthentication.  Depending on your PAM configuration, # PAM authentication via ChallengeResponseAuthentication may bypass # the setting of "PermitRootLogin without-password". # If you just want the PAM account and session checks to run without # PAM authentication, then enable this but set PasswordAuthentication # and ChallengeResponseAuthentication to 'no'. UsePAM yes   This is sshd_config of ubuntu system. How to show that Klein four-group is a normal subgroup of the alternating group $A_4$ Lower bound on energy is potential minimum Suppose we have a particle of mass $m$ that is in an eigenstate $|\psi\rangle$ of the Hamiltonian $\hat{H}=\hat{T}+\hat{V}$, where $\hat{T}$ is the kinetic energy operator and $\hat{V}=V(\hat{r})$ is the potential energy operator. If the potential has lower bound $V_0$, then is it necessary for the energy eigenvalue $E$ of $|\psi\rangle$ to be greater than $V_0$? Classically this is true, since we regard negative kinetic energy as physically unrealizable/meaningless. However, I don't know if I can necessarily say the same in the quantum case. For example, what I'm tempted to do is write  $$\langle\psi | \hat{T}|\psi \rangle = \langle\psi | E-\hat{V}|\psi\rangle$$  and say "If $E&lt;V_0$, then the RHS is necessarily negative, implying the LHS is as well, which we will regard as physically meaningless. If $E=V_0$, then $|\psi\rangle$ is trivial.", but I'm not sure if that's right.   Confused by that, I then wanted to show that, if $E&lt; V_0$, then a non-trivial $|\psi\rangle$ is non-normalizable. However, I'm not entirely sure how to do this. How many Naruto Shippuden dubbed episodes are there? I am watching Naruto and I am currently on episode 164. How many episodes of Shippuden do they have dubbed, and are they still dubbing it? QGIS locked into fullscreen mode on Ubuntu 12.04 No crash in this case, but I made the mistake of toggling to fullscreen mode on my netbook running Ubuntu 12.04. It's now impossible to escape , and it seems to have disabled the popout unity launcher as well. Steps I've already taken:   Alt-Tab to move to a different program, then back - QGIS remains in fullscreen Alt-V, Ctrl-F and F11 get no response I've unistalled QGIS, deleted the /.qgis/ profile data folder, and reinstalled. Still launches fullscreen   To add to the weirdness, it now launches - still in fullscreen - into a different workspace than the active one.  I realize this has the sound of a Unity problem, but it's just this program that has a malfunctioning UI.  Thanks to all the crew; this in no way changes my opinion of QGIS as an essential tool. How do I limit the running time of a BASH script I have a long running BASH script that I am running under CYGWIN on Windows.  I would like to limit the script to run for 30 seconds, and automatically terminate if it exceeds this limit. Ideally, I'd like to be able to do this to any command.  For example:  sh-3.2$ limittime -t 30 'myscript.sh'   or   sh-3.2$ limittime -t 30 'grep func *.c'   Under cygwin the ulimit command doesn't seem to work.   I am open to any ideas. Installing Ubuntu on one of two hard drives How do I install software using the Ubuntu Software Center? The title says it all. I'd like to know how I can install software - an example is the Chromium web browser. OSX Server: should I use Open Directory? Exclude folder using `find` command I'm using the find command on a Mac to search for a folder called test1. Now test1 folder could be present in the .Trash folder also. How do I exclude the .Trash folder from getting reported in search results or basically any folder I wish to exclude?  $ find $HOME  -name test1 -type d /Users/theuser/.Trash/test1 /Users/theuser/test1  /Users/theuser/Downloads/test1    I want the result to be just  /Users/theuser/test1 /Users/theuser/Downloads/test1    I used grep:  find $HOME  -name test1 -type d | grep -v '.Trash'    to filter out the .Trash result, but I'm interested in knowing if using find alone achieves the same results. How to remove duplicate values from an array in PHP How can I remove duplicate values from an array in PHP? I was surprised to discover my dictionary had this entry for dilemma:     a situation in which a difficult choice has to be made between two or more alternatives, esp. equally undesirable ones   The notion of dilemma meaning two or more flies against what I was taught about the word. The very idea of a  is specifically based on the number two.  Has my dictionary merely updated its definition to encapsulate the many people who use dilemma for more than two equal choices? Or was someone in my youth being unnecessarily pedantic? I realize this is a long shot, but my phone was lost or stolen a few hours ago.  At the time it was stolen, I didn't have any specific applications installed to track it or wipe the data. So... my bad. I'm hoping the fact that I have a pattern lock will at least prevent anyone from accessing my data.  My question is, do I have any options for tracking or data wipe after the fact? (I'm more interested in tracking.)  Note: I have read similar questions, but unless I'm mistaken, they all address the question in terms of preparation before losing the phone. I'm asking about fallback options after losing the phone. How can I determine that I am looking at the block I need? I want to execute a command if I am looking at a specific block. A command should only be executed if it is targeted. Is Lambert Academic Publishing a reputable company? I was contacted by the Acquisition editor of Lambert Academic Publishing (LAP) to publish my bachelor's thesis as a printed book. Is LAP any good? I have no idea about it; I have just heard that it's a freelance publishing house. How to create functions of arbitrary number of variables? Sql Server 'Saving changes is not permitted' error ► Prevent saving changes that require table re-creation