I have been trying to set environment variables that would be saved upon reboot, but without success.   When I set variables using the export or setenv command, as root or any other user, it gets saved on the session until reboot. After reboot, the variables are lost.  In particular, I need to set $JAVA_HOME.  So I do like this     but nothing is working as I indicated.  What am I doing wrong?
This is irritating me. I seen several suggestions (all using different files and syntax) and none of them worked.  How do I set an environment variable for a specific user? I am on debian squeeze. What is the exact syntax I should put in the file to make ABC = "123"?
Sorry for the bad English. I'm trying to use the tikz-cd package to make commutative diagrams. My code  \documentclass{article} \usepackage[brazil]{babel} \usepackage{tikz-cd} \begin{document} \begin{tikzcd} A \ar[r, "x"] &amp; B \end{tikzcd} \end{document}    The problem occurs when putting a name under the arrow, the syntax "x" is incompatible with the brazil option of the babel package. When exchanging brazil for english it works normally. I already tried using  \usepackage[main=brazil, english]{babel}, \usepackage[brazil, english]{babel} e  \usepackage[brazil, main=english]{babel}   But it did not work. I also tried to use  \usepackage[english, brazil]{babel} \usepackage{polyglossia} \setmainlanguage{brazil} \setotherlanguages{english}   And finally  \selectlanguage{english}   However, it only works if I remove the option brazil How could we improve our planned post notice improvements? Megan has written a .  I've seen a bunch of discussion about it on chat - but it feels like having it purely on the blog is a little clunky.  So specifically - what does the MSE community feel about the proposed post notices for closed questions? What's missing, or what should be added? What are some of the lessons we've learnt that could be helpful here? Show that a matrix is nilpotent. Let $A,B \in \mathbb{M}_n (\mathbb{C})$. If $A^2B + BA^2 = 2ABA$ then exist $k \in \mathbb{N}$ where $(AB-BA)^k = 0$.  I tried solve with minimal polynomial, but I did not have much effect. Search for all files with a .sql extension in folders and sub folders Proof that the relation $5 \mid (a + 4b)$ is symmetric and transitive Take the relation $R$ to be defined on the set of integers:  $$aRb \iff 5 \mid (a + 4b)$$  As part of a larger proof, I have to show that $R$ is both symmetric and transitive. I'm lost.  I see the first steps, but I can't find how to progress further. Here's what I have at this point:    Proof of Symmetry  We have to prove that if $5 \mid (a + 4b)$, then $5 \mid (b + 4a)$. Clearly, this is true if $a = b$, but apart from that, it's unclear in my mind.  Proof of Transitivity  We have to prove that if $5 \mid (a + 4x)$ and $5 \mid (x + 4b)$, then $5 \mid (a + 4b)$.    I've fiddled around with sample values, but I still don't see it. I'm pretty lost here. Thoughts? I accidentally moved all folders from root to a subfolder. (/bin, /etc, /home, /lib, /usr... all moved) The only ones that were not moved, since they were in use, are  /bak, /boot, /dev, /proc, /sys.  Now, any command that I try to execute will simply not happen. I constantly get "No such file or directory".  I am connected through ssh and through ftp, but I cannot move files through ftp, as direct SU login is disabled. I also have access to the actual server if I need to do something directly from there.  I'm assuming I would need to edit a configuration file in order to tell it where to find the /bin folder and that would help me get access again, but I don't know which file that would be or how to do it (since I can't even run chmod to change permissions).  Is there any way out of this other than re-installing?  I am working on an old version of CentOS.  I'm extremely new to the world of Linux, hence this action and the question... How to scroll in a terminal using keyboard? How can I scroll in bash using only the keyboard? If it's not possible in bash, are there any other shells that support this? Allow more than one @name notification per comment Now this is probably a surprise to many since I always see thousands of comments like :  @Sarfraz, @balpha just told you they did in the first comment he wrote. Also, allowing only one Stack Overflow user to be logged in per IP address would be problematic for networks with shared IPs.  What's surprising is that apparently the notification will trigger only for Sarfraz and not for balpha. As you can see from the :  Only one person can be replied to at a time in a comment. The first one in the string wins.  I propose to increase the limit to let's say 3 or 5 people; it won't hurt (never seen that feature being abused) and especially many people believe it already works that way. Suddenly, to everybody's surprise, the silent Mr.Smith swung around and addressed Barbara.   The dinner was served by a silent Mrs. Keats.   I saw an infuriated Jennifer, who started shouting at me the moment I opened the door.   It seemed Walter didn't pay any attention to a tearful Kitty.   She hasn't got lovely eyelashes like marvellous Monica.   I bet your Mum kept you well clear of horrible Jesse.      The rule I learned at university said that the is used when the adjective a permanent quality of the person in question. E.g. 'I met the wicked Matilda the other day' would suggest that Matilda is inherently wicked.  The indefinite article a/an, on the other hand, would denote the mood or an unusual quality of the person described.  However, recently I've come across a lot of examples where no article is used with names modified by adjectives (see examples 5 and 6 above).   Can anyone explain why there are no articles in sentences 5 and 6? How run a .jar file with a double-click? Prove by induction that for all $n \geq 3$: $n^{n+1} > (n+1)^n$ Proving there is a sequence convergent to a limit point of a set without axiom of countable choice? Often, we use a construction like this: Given a subset $ A $ of a metric space and its limit point $ a $, we know that for every $ \epsilon &gt; 0 $ there is another point $ x $  different from $ a $ such that $ d(x,a) &lt; \epsilon $. So for every natural $ n $ we let $ a_n $ be such a point within $ 1/n $ of $ a $, which gives us a sequence convergent to $ a $.  My question is, is the axiom of countable choice needed for this construction, or is it formally correct just in ZF? How can I avoid Java code in JSP files, using JSP 2? Why is `enjoy to [verb]` incorrect I can say:     I love to read. I hate to read.   But it must be:     I enjoy to read. I enjoy reading.   What is enjoy so different? Enabling Nvidia driver messes up splash screen How do I tail a log file and keep tailing it when the latest one changes date? Why does my shell script choke on whitespace or other special characters? Or, an introductory guide to robust filename handling and other string passing in shell scripts.  I wrote a shell script which works well most of the time. But it chokes on some inputs (e.g. on some file names).  I encountered a problem such as the following:   I have a file name containing a space hello world, and it was treated as two separate files hello and world. I have an input line with two consecutive spaces and they shrank to one in the input. Leading and trailing whitespace disappears from input lines. Sometimes, when the input contains one of the characters \[*?, they are replaced by some text which is is actually the name of files. There is an apostrophe ' (or a double quote ") in the input and things got weird after that point. There is a backslash in the input (or: I am using Cygwin and some of my file names have Windows-style \ separators).   What is going on and how do I fix it? Suppose there is a message that is encrypted with AES-128-CBC.  The message is as follows, new lines are used to delimit the 16 byte boundary for each block:  Wire funds from: Alice to Bob in   the amount of $ 1   Because this message is encrypted using CBC mode,  any modification of the first block of cipher text would propagate throughout the message.   However, the amount of the fund transfer falls in the last block.  I am under the assumption that an attacker can use the property of  to alter the last block and produce a valid amount that is greater than \$1 in far fewer than $2^{128}$ operations.   Is this a correct assumption?  Is there a name for this attack or do you know of a real world example?    My instinct is that if you just need one byte of the 16 byte block to be of a specific value then it would only require $2^8$ operations because the other 120 bits of the plain text could be any value. For example lets say we wanted the last block of cipher text to decrypt to 9\0 (where \0 denotes a single null byte, and the message would be interpreted as \$9), then it would take only $2^{16}$ operations to find this cipher text block.  Is there something I am missing? I think the title says it. Did expansion of the universe steal the energy somehow? What is the US Visa Waiver Program and what is an ESTA?