I have this  echo $line Thisisaline.   I was wondering why is this not working:  if [[ "$line" =~ "[a-zA-Z]+\.$" ]] ; then echo "hello"; fi   Above regex gives no output.
The following code  number=1 if [[ $number =~ [0-9] ]] then   echo matched fi   works. If I try to use quotes in the regex, however, it stops:  number=1 if [[ $number =~ "[0-9]" ]] then   echo matched fi   I tried "\[0-9\]", too. What am I missing?  Funnily enough,  suggests this should work.  Bash version 3.2.39.
What does the symbol with a shield and two swords next to clan members' names mean? When I open my clan roster, I now notice there is a symbol that has a shield + two swords next to most clan member's name.  What does this signify?  Are they ready for clan battles? Is anti-gravity (i.e. repulsive gravity) possible in theoretical physics? Is  (i.e. repulsive gravity) possible in string theory?  I have read some articles about scientists making assumptions about the existence of anti-gravity, but is it possible in string theory? I'm wondering whether it's possible to downgrade sfdx-cli to use an earlier version?  I'm trying to debug an issue with using it in pipeline scripts.  When I run sfdx version --core I get sfdx-cli 7.28.7 (core) .    If I run  sfdx version I get  sfdx-cli/7.28.7-7bceba6f24 darwin-x64 node-v10.15.3 .  If I do cat package.json inside the actual package dir for sfdx-cli after doing npm install sfdx-cli@7.26.0 I get  "sfdx-cli": "^7.26.0"  Why does it then show that the version is 7.28.7?  How can I force the lower version to have preference?  I do understand that this question is not really salesforce specific but hopefully someone has run into the same problem. Indirect return of all elements in an array The Bash man page describes use of ${!a} to return the contents of the variable whose name is the contents of a (a level of indirection).  I'd like to know how to return all elements in an array using this, i.e.,  a=(one two three) echo ${a[*]}   returns  one two three   I would like for:  b=a echo ${!b[*]}   to return the same.  Unfortunately, it doesn't, but returns 0 instead.  Update  Given the replies, I now realise that my example was too simple, since of course, something like:  b=("${a[@]}")   Will achieve exactly what I said I needed.  So, here's what I was trying to do:  LIST_lys=(lys1 lys2) LIST_diaspar=(diaspar1 diaspar2)  whichone=$1   # 'lys' or 'diaspar'  _LIST=LIST_$whichone LIST=${!_LIST[*]}   Of course, carefully reading the Bash man page shows that this won't work as expected because the last line simply returns the indices of the "array" $_LIST (not an array at all).  In any case, the following should do the job (as pointed out):  LIST=($(eval echo \${$_LIST[*]}))   or ... (the route that I went, eventually):  LIST_lys="lys1 lys2" ... LIST=(${!_LIST})   Assuming, of course, that elements don't contain whitespace. Is there a package to secure rendered pdf with a password? Is there a package and command that can secure rendered pdf with a password? How can I change permissions on external drives? I wanted to change permissions on my external drives that are automounted however I have tried by sudo nautilus and then going to gui and permissions and changing it however it does not let me.  I ran the ls -l and get  drwx------ 1 xbmc xbmc   the gui shows below.  owner xbmc folder access create and delete files file access ---  Group xbmc folder access none file access ---  others folder access none file access ---   how can I change it so that everyone has permission to access the drive and ALL folders/files inside of it. I am trying to get plexmedia server running and I cant see my drives via the webpage manage to add it to my source to be able to stream my content.  I want to change the "others" access so that I can access all my drives on the /media path to get read and write for all my folders from anywhere.  you can see my drives that are mounted here (external drives are #18,19,20) Antiresonance of multiple parallel decoupling capacitors: use same value or multiple values? My quesiton: Is it better practice to put same-valued capacitors in parallel of capacitors of different values to decouple the high-frequency noise caused by digital ICs? Background Digital IC need a decoupling capacitor close to their supply pins to ensure a stable voltage during power transients and to deal with noise (mostly to prevent noise generated by the IC to affect neighboring circuitry). It seems sensible to place a bulk capacitor (say 10-100uF), to act as an energy reservoir, and several smaller capacitors to deal with higher frequencies. The reason to place several small capacitors instead of just one is to deal with their Equivalent Series Inductance (ESL), which in practice, causes them to behave like an LC circuit. The effect of anti-resonance Yet, here is where best design practices and electronic myth seem to get mixed up and confusing to me. Most electronic engineers I have met like placing several decoupling capacitors of different values in parallel (with the smaller capacitors closer to the IC). The logic behind it is that the each capacitor takes care of a different noise frequency as depicted in Figure 1.  Figure 1: Impedance over frequency of three different value capacitors in parallel (cyan) vs their individual contribution (brown, blue, red). Image taken from . Note the small anti-resonance peak. It seams no major trouble , and the overall behavior of the three different capacitors in parallel is vastly superior to their individual decoupling capabilities. However, I have read in  by [Henry W. Ott] that placing capacitors of different values may cause a much greater antiresonance-peak which can be very harmful for our designs (see Figure 2). In fact, it amplifies any noise that falls into the anti-resoance frequency range, which is corroborated by .  Figure 2: from Electromagnetic Compatibility Engineering, by Henry W. Ott, section 11.4.4. The 15nH inductance makes reference to the capacitors ESL. Find the volume of a cone whose length of its side is $R$ How can i compute the volume of a cone whose length of its side is $R$ and the vertex of the cone forms an angle $2θ$ .  The top cone is a cap of a sphere of radius $R$.    I tried to solve first in 2 dimension and then use solid of revolution:    Some help please to find the volume of this cone. What is the world's biggest Schrodinger cat? Email to salesforce error While sending an attachment as an email to be attached to the salesforce record.Salesforce is giving the below given error.  Generating server: mx1.madison.gov  6-2j26dncatawfg1112dv2uwxupq9hzfgmjrrlrn2rx48cxm93nt.8-dea8eae.c.le.salesforce.com mx1-asg.mta.salesforce.com # #SMTP#  Is this salesforce problem or it is the Internal company server problem as I could see that error mentions company server name also.But to me doesn't look like company server error. Breitbart today:   What is the source for the term nothing-burger? How to remove title entry in the bibliography contents? I use plain bibliography style for my book. When I compile it, by default, I get the details including the title in my reference. like this:     H. J. C. Berendsen, J. P. M. Postma, W. F. van Gunsteren, a. Dinola, and J. R. Haak. Molecular dynamics with coupling to an external bath. J. Chem. Phys., 81:3685-3690,1984.   This is too long and I have more than 100 such references which makes the document too long. How can I force it to remove the title from this reference? something like this:     H. J. C. Berendsen, J. P. M. Postma, W. F. van Gunsteren, a. Dinola, and J. R. Haak.  J. Chem. Phys., 81:3685-3690,1984.   Your answer will be greatly appreciated.  By the way, I still would like to use the plain bibliography style. My usb mouse sleeps after 5 seconds of inactivity when running on battery power. It wakes uo again when i press any button on the mouse. This is really annoying.  I have made lsusb, and I noticed my mouse is   Bus 001 Device 012: ID 04d9:2083 Holtek Semiconductor, Inc.  I have checked my /sys/bus/usb/devices/usb1/power/autosuspend but it is already set to 0, and the directory usb1 has many subdirectories which also have autosuspend files, and i dont know how to edit them.  Also, I would like a permanent solution, which would work for any mouse, on any of my 3 usb ports. Any ideas?  Using: Ubuntu 12.04 64bit How exactly do I install Minecraft Mods and what is Forge? I'm having a really, really hard time figuring out how to install mods on Minecraft. I've looked everywhere I can think of for help but the information is almost always outdated or unhelpful.  I've seen on several sites about the use of something called Forge. The Mod I want to use requires 1.6.4 Forge and I have both Forge and the Mod folders sitting in my downloads folder.  I haven't installed any kind of mods for any game prior to this and I have little clue to the technical side of Minecraft, so please keep this in mind when you give me an answer please!  Things that might help you figure out how to help me:   I want to play this mod  and am using the 1.6.4 Forge given on a link that website gives Inequality $\sqrt{1+x^2}+\sqrt{1+y^2}+\sqrt{1+z^2} \le \sqrt{2}(x+y+z)$ If $x&gt;0$, $y&gt;0$, $z&gt;0$ and $xyz = 1$ then   $$\sqrt{1+x^2}+\sqrt{1+y^2}+\sqrt{1+z^2} \le \sqrt{2}(x+y+z)$$   I tried using $\displaystyle x = \frac{a}{b},y = \frac{b}{c}$ and $\displaystyle z = \frac{c}{a}$ substitution,  $\displaystyle \sum_{cyc} \frac{\sqrt{a^2+b^2}}{b} \le \sqrt{2}\left(\frac{a}{b}+\frac{b}{c}+\frac{c}{a}\right) \\ \displaystyle  \iff 6+ 2\sum_{cyc}\frac{\sqrt{(a^2+b^2)(b^2+c^2)}}{bc} \le \sum_{cyc}\frac{a^2+b^2}{b^2} + 4\sum_{cyc}\frac{b}{a}$  So it would suffice if we showed $\displaystyle \sum_{cyc}\frac{\sqrt{(a^2+b^2)(b^2+c^2)}}{bc} \le 2\sum_{cyc}\frac{b}{a}$  Squaring again does not lead anywhere nice. Is the last inequality true ? If not is there a better way of showing the result ? Modus Operandi. Formulae for Maximum and Minimum of two numbers with a + b and $|a - b|$ I came across the following problem in my self-study of real analysis:     For any real numbers $a$ and $b$, show that $$\max \{a,b \} = \frac{1}{2}(a+b+|a-b|)$$ and $$\min\{a,b \} = \frac{1}{2}(a+b-|a-b|)$$   So $a \geq b$ iff $a-b \ge0$ and $b \ge a$ iff $b-a \ge 0$. At first glance, it seems like an average of distances. For the first case, go to the point $a+b$, add $|a-b|$ and divide by $2$. Similarly with the second case.   Would you just break it up in cases and verify the formulas? Or do you actually need to come up with the formulas? Does either pill actually do anything? When Morpheus offers the pill choice to Neo, they are still in the Matrix. That leads me to belive that none of the pills are real thus having no particular effect in the real world. Was it some sort of placebo effect that freed Neo from the Matrix or do the pills have an actual effect? Question about "surely" and "certainly" Today I saw a sentence:  She surely can do it.  What does that mean? How does it differ from:  She certainly can do it. Surely she can do it.  This slight difference in meaning of those sentences I am not able to notice. Could you please help me? Thanks in advance! I wonder whether there is any automatic way of determining (at least roughly) the Big-O time complexity of a given function?  If I graphed an O(n) function vs. an O(n lg n) function I think I would be able to visually ascertain which is which; I'm thinking there must be some heuristic solution which enables this to be done automatically.  Any ideas?  Edit: I am happy to find a semi-automated solution, just wondering whether there is some way of avoiding doing a fully manual analysis. VMware won't work after Ubuntu Upgrade I upgraded to Ubuntu 15.10 and now if I want to open VMware Player it doesn't do anything. I also uninstalled and installed it again, still nothing.  What can I do?