I was reading about packages, and I wondered what are package names for commands like "ls" and "echo"? These commands were installed on every Linux machine I've worked with, and I don't know which package installs them.  $ sudo apt purge ls   Reading package lists... Done   Building dependency tree          Reading state information... Done   E: Unable to locate package ls  $ sudo apt purge echo   Reading package lists... Done   Building dependency tree          Reading state information... Done   E: Unable to locate package echo   And the same thing happened for lots of other commands.  Q1. Is there any package which has all these primary commands in?  Q2. Do "ls" or "echo" or ... have a package? or they are just some commands?  Q3. How can I find the package name of commands like "ls", "echo", "read" and so other?
Simple enough question: is there some shell command (or GUI method) I can use that, given the path to a file on my system, tells me what package put it there? Assuming the file did in fact come from a package, that is.  Bonus question: what if it's a file that isn't installed on my system? Is there, say, a website that will let me look up a file and see what packages, if any, provide it?
Failed review audit - for me quite clearly off-topic, can it be removed from the audit set? POSIX compliant way to redirect stdout and stderr to a file I am trying to write a script which is POSIX compliant, so it can run on any *nix system (Debian, Fedora, CentOS, AIX, Arch... ALL of them). When it comes to redirection, I am rather confused on what is supported by POSIX and what is not.  If I redirect ls -l file missingfile &amp;&gt; out.txt this works perfectly in bash. The line from stderr complaining that missingfile doesn't exist, and the permissions output from file, are both in out.txt. However, I believe this is only working because these shells support more than just POSIX standard operators. Upon researching this question I've come across conflicting answers.  , for example, seems to imply that &amp;&gt;, &gt;&amp;, &gt;&gt;&amp; and &amp;&gt;&gt; are non-standard operations. However,  explicitly states that some-program &gt; some_file 2&gt;&amp;1 is POSIX compliant. Does this mean that the &gt;&amp; operator (using digits for stderr &amp; stdout) is POSIX compliant whereas using &amp;&gt; to auto redirect both stderr and stdout to a file is not POSIX compliant? Or are both &amp;&gt; and &gt;&amp; not POSIX compliant / POSIX compliant (one of these two people are wrong)?  I considered just avoiding the &amp; sign completely and using ls -l file missingfile &gt;out.txt 2&gt;out.txt however this comes with its own issue. Running the ls command this way causes the shell to open two file handles for out.txt, both pointing to offset 0 in the file. So when ls looks for these two files, one of the messages gets clobbered.  What one would expect ls -l file missingfile &gt;out.txt 2&gt;out.txt to output:  -rw-r--r-- 1 blah blah 0 Jun  3 13:18 file ls: cannot access 'missingfile': No such file or directory   What is actually output:  -rw-r--r-- 1 blah blah 0 Jun  3 13:18 file le or directory   What is the best way to redirect both stdout and stderr to a file in a POSIX compliant fashion? Wouldn't it be a good idea to be able to vote for questions to be moved to any Stack Exchange site? For example, I just voted  as off topic, but that was all I could do. I wish I could've voted it be moved to .  It's OK to have the predefined list of sites that is now when voting to move, but it would be nice to have a more link, where we could pick any Stack Exchange site.  Here's a quick mockup of how I see this implemented:    When the more link is clicked, a list of all the Stack Exchange sites should appear. Is there any way to recover deleted files which may have since been overwritten? Posting to friends' wall with Graph API via 'feed' connection failing since Feb 6th 2013 If $a^3 =a$ for all $a$ in a ring $R$, then $R$ is commutative. How do I use a particular font for a small section of text in my document? The standard font packages make global changes to the fonts in my document. What if I want to use a particular font for just a portion of my text?   How do I find the right name of the font? How do I select the font? How do I restrict the scope of the font change?     There are separate answers for different flavors of TeX (quick links): How are the best director award winners chosen? I do not understand how the best director awards are determined each year. It seems impossible to assess the method of a movie director unless you are part of the crew.  So, how do the nominators/judges assess the directors' performance each year? Finding inverse of polynomial in a field I'm having trouble with the procedure to find an inverse of a polynomial in a field. For example, take:     In $\frac{\mathbb{Z}_3[x]}{m(x)}$, where $m(x) = x^3 + 2x +1$, find the inverse of $x^2 + 1$.   My understanding is that one needs to use the (Extended?) Euclidean Algorithm and Bezout's Identity. Here's what I currently have:  Proceeding with Euclid's algorithm:  $$ x^3 + 2x + 1  =(x^2 + 1)(x) + (x + 1) \\\\   x^2 + 1 = (x + 1)(2 + x) + 2$$  We stop here because 2 is invertible in $\mathbb{Z}_3[x]$. We rewrite it using a congruence:  $$(x+1)(2+x) \equiv 2 \mod{(x^2+1)}$$  I don't understand the high level concepts sufficiently well and I'm lost from here. Thoughts?  Wikipedia has a page on this we a , but it's still not clear in my mind.  Note that  has almost the same title, but it's a level of abstraction higher. It doesn't help me, as I don't understand the basic concepts.  Thanks. A commutative ring is a field iff the only ideals are $(0)$ and $(1)$ Parallel file copy from single source to multiple targets? I have a several large files on optical media I would like to copy to multiple targets - in this case I have two hard drives attached to the same computer. Is there a utility that can function like:  copy source target1 target2 ... targetN How to manage users and groups using GUI? Just switched from 10.04 to 11.10. I'm wondering about the limited options in the GUI for managing users and groups. Where is the old GUI to change groups, id's, etc. I know that I can do this from cli, that's no problem. But I want this comfortable GUI back. How to calculate Network Service Areas in QGIS? How can I get out of the debt-trap as quickly as possible? I have a credit card with 30% interest and a real estate loan with 11% interest. The amount of debt on my card is lower than the real estate loan.   I want to redeem the installments of the real estate loan, but I can't do it because the credit card debt takes all my money.    What can I do in this situation? How can I get out of the debt-trap as quickly as possible?   I have a 4-room house and 2 cars, and 2 children who have to go to school, that's why there are a lot of fix expenses. I installed a mainline kernel for testing purposes. I would like to set grub to boot from the older kernel by default.  I know I can set the GRUB_DEFAULT=0 setting for the first page of grub but how do I set it to boot by default from one kernel in the second page (Advanced page)?  I would prefer doing this without installing other software (ex. grub-customizer).     Related Questions: How can I explain to people that the phrase “off of ” is grammatically incorrect? What is the importance of eigenvalues/eigenvectors? "Heard me [infinitive]" vs. "heard me [present participle]" "Heard me [infinitive]" vs. "heard me [present participle]"             At that time, you wouldn't have heard me talk about it.   At that time, you wouldn't have heard me talking about it.         At that time, you wouldn't have heard me condemn it.   At that time, you wouldn't have heard me condemning it.         Which one of the above sentences are incorrect and why? Should initial e's after h-dropping be capitalized? A new Victorian-set British novel begins sentences containing h-dropping with lower-case e's, as in " 'e took my money, 'e did." This seems incorrect but I'm at a loss to find the rule. How do I upgrade to a newer version of Ubuntu?