Problems with basics
How do I install applications in Ubuntu?
How do I run 32-bit programs on a 64-bit Debian/Ubuntu? I have a 64-bit (amd64 a.k.a. x86_64) Debian or Ubuntu installation. I need to run 32-bit (i386/i686) programs occasionally, or to compile programs for a 32-bit system. How can I do this with a minimum of fuss?  Bonus: what if I want to run or test with an older or newer release of the distribution? openSuse, new user cannot login I am using openSuse 12.3.  I have created a new user using:  linux-amvn:~ # useradd -m -G users,dev -s /bin/bash -p pass123 harbir-PC   The user harbir-PC is not able to login, when I try to log using ssh. I went ahead and looked into the /etc/passwd file and I see the following:  harbir:x:1000:100:harbir:/home/harbir:/bin/bash kdm:x:489:487:KDM Display Manager daemon:/var/lib/kdm:/bin/false harbir-PC:x:1001:100::/home/harbir-PC:/bin/bash   There is a difference between the user harbir and harbir-PC.  I have no problem with the user harbir (who I have created during installation), but I need to login using the user harbir-PC.  I also checked the /etc/shadow, and passwords are encrypted. How do I programmatically update the allowed values of a list field? I have created a field_time_zone field for the Article content type. I want to set the allowed values for that field to the values returned from system_time_zones(). For this, I implemented hook_form_alter() using the following code. $zones = system_time_zones(); $entityManager = \Drupal::service('entity_field.manager'); $fields = $entityManager-&gt;getFieldStorageDefinitions('node', 'local_market'); $options = options_allowed_values($fields['field_time_zone']);  if(empty($options)) { $options =  $zones; $form['field_time_zone']['widget']['#options'] = $options; }  The code adds the desired values, but the node cannot be saved, as it throws the following error.  The value you selected is not a valid choice.  How can I set the allowed values for a text (list) field? How do I tell which point-and-shoot cameras take good low light photos? Automatically convert quotations in the form of "abc" to become ``abc" Find where java class is loaded from joomla 2.5 in module install.mysql.utf8.sql dosent work Do I need a visa for a connecting flight to Japan? I'm going to the Philippines this October and would like to layover in Japan. I found a reasonably priced ticket with a 15-hour layover to Haneda, however, I have to transfer to Narita. Do I need a visa since I'm going to have to stay at a hotel and ride a bus to travel to Narita airport? Thank you! Lag compensation with networked 2D games I want to make a 2D game that is basically a physics driven sandbox / activity game. There is something I really do not understand though. From research, it seems like updates from the server should only be about every 100ms. I can see how this works for a player since they can just concurrently simulate physics and do lag compensation through interpolation.  What I do not understand is how this works for updates from other players. If clients only get notified of player positions every 100ms, I do not see how that works because a lot can happen in 100ms. The player could have changed direction twice or so in that time. I was wondering if anyone would have some insight on this issue.  Basically how does this work for shooting and stuff like that?  Thanks Mean Value theorem problem?(inequality) I'm trying to solve this mean value theorem problem but confused where to start,     If $0&lt;a&lt;b$ prove that $(1-\frac{a}{b})&lt;\ln\frac{b}{a}&lt;\frac{b}{a}-1$   Can someone please lend me a hand? What is the difference between const_iterator and non-const iterator in the C++ STL? What is the difference between a const_iterator and an iterator and where would you use one over the other? How to add CC to a webform email? Why uniform closure $\mathscr{B}$ of an algebra $\mathscr{A}$ of bounded complex functions is uniformly closed? Let $\mathscr{A}$ be an algebra of bounded complex functions. (Or if necessary, continuous and domain of functions is compact)  Definition:  $\mathscr{B}$ is uniformly closed iff $f\in\mathscr{B}$ whenever $f_n\in \mathscr{B} (n=1,2,\cdot)$ and $f_n\rightarrow f$ uniformly.  $\mathscr{B}$ is the uniform closure of $\mathscr{A}$ iff $\mathscr{B}$ is the set of all functions which are limits of uniformly convergent sequences of members of $\mathscr{A}$.  ============  Let $\mathscr{B}$ be a uniform closure of $\mathscr{A}$.  How do i prove that $\mathscr{B}$ is uniformly closed in ZF?  Does Stone-Weierstrass theorem require choice since it is critical to prove Stone-Weierstrass Theorem? Example where schema are better than multiple databases In several database systems (e.g., PostgreSQL and MS SQL Server) there is a concept of schema. There are many questions out there asking what schema are and how they are used; here is a . Usually the answer boils down to "namespace" and "permissions". However, what remains unclear to me is why a schema has any advantage over just adding a new database. A different database allows one to have both separate namespaces and permission assignments.  Can someone provide an example in PostgreSQL where multiple schema in a single database provide an advantage over multiple databases without schema? From a purely organizational perspective they appear equivalent. Properties of the greatest common divisor: $\gcd(a, b) = \gcd(a, b-a)$ and $\gcd(a, b) = \gcd(a, b \text{ mod } a)$ Prove that (a) gcd(a, b) = gcd (a, b – a) (b) Let r be the remainder if we divide b by a. Then gcd(a, b) = gcd(a, r).  I solved part a like: Assume a=pcommonpa b=pcommonpb gcd (a,b) = pcommon b-a = pcommon*(pb-pa)  So: gcd(a, b-a) = common again But I need help for part b guys I can solve it but I need a mathematical expression. Reconciling different definitions of left-exact functor What is the word for act of monotonously demanding for something (many be a toy) repeatedly? The title says it all, just wondered if accessing the iOS will count towards your consecutive visited days. I just tried to access a folder like so:  \\somecomputeronmynetwork\somelocation$   When going to this location I'm prompted for a user name and password.  I put one in, and it let me in fine.  Now I need to remove that login, so I can try a different user name and password.  What's the easiest way to do this? What overwrites /etc/resolv.conf on every boot? I was given the files for a mini linux, that boots directly into firefox. It works for all it should be doing, only that I do not get an internet connection.  We have 3 DNS servers in the network, which all work. I can ping them, too. But when trying to ping google.de or wget google.de I get a bad address error.  nslookup google.de works for some reason.  I tracked the issue down to my resolv.conf on the booted system not having the same contents as the resolv.conf that I put into the .iso file.  I tried understanding all the factors that go into creating and modifying resolv.conf. I'm not quite sure I got it all, but I definitely didn't find my solution there.  So as a last ditch effort, I tried making the resolv.conf file immutable using   :~# chattr +i /etc/resolv.conf   When rebuilding and booting again to my surprise my file was renamed to resolv.conf~ and in its place was the same standard file that has been haunting me.   The file contents make me believe it gets the information from the network itself. When starting the .iso in Virtualbox without internet access, my file is being kept as it is.  I tried changing /etc/dhcp/dhclient.conf to not get the information from the net, by deleting domain-name-server and domain-name-search from the request part of the file.  Didn't work unfortunately.  I don't have the NetworkManager installed. The iso is based on Ubuntu 14.04.  There is probably vital information missing. I'm happy to provide it.  UPDATE:  I think I found the file that clears resolv.conf.  It seems to be /usr/share/udhcpc/default.script  #!/bin/sh  # udhcpc script edited by Tim Riker &lt;Tim@Rikers.org&gt;  [ -z "$1" ] &amp;&amp; echo "Error: should be called from udhcpc" &amp;&amp; exit 1  RESOLV_CONF="/etc/resolv.conf" [ - n "$broadcast" ] &amp;&amp; BROADCAST="broadcast $broadcast" [ -n "$subnet" ] &amp;&amp; NETMASK="netmask $subnet"  case "$1" in     deconfig)         /bin/ifconfig $interface 0.0.0.0         for i in /etc/ipdown.d/*; do             [ -e $i ] &amp;&amp; . $i $interface         done         ;;      renew|bound)         /bin/ifconfig $interface $ip $BROADCAST $NETMASK          if [ -n "$router" ] ; then             echo "deleting routers"             while route del default gw 0.0.0.0 dev $interface ; do                 :             done              metric=0             for i in $router ; do                 route add default gw $i dev $interface metric $((metric++))             done         fi          echo -n &gt; $RESOLV_CONF # Start ----------------           [ -n "$domain" ] &amp;&amp; echo search $domain &gt;&gt; $RESOLV_CONF         for i in $dns ; do             echo adding dns $i             echo nameserver $i &gt;&gt; $RESOLV_CONF         done         for i in /etc/ipup.d/*; do             [ -e $i ] &amp;&amp; . $i $interface $ip $dns          done # End ------------------         ;; esac  exit 0   It's part of the udhcpc program. A tiny dhcp client, that is part of busybox  Will investigate further.    UPDATE2 AND SOLUTION:  I commented the part out (#Start to #End), that seemingly overwrites the /etc/resolv.conf file and sure enough. That was the culprit. So an obscure script caused all this trouble.  I changed the question to reflect, what actually needed to be known to solve my problem, so it would be easier to find for people with the same problem and so I could accept an answer.  Thanks for the help here in figuring things out.