rsync with consecutive ssh
rsync a file from serverC to serverA through serverB
How to read the following Itinerary What do the abbreviations mean in the following itinerary:     2  EK 641 L 29NOV 2 KBLDXB HK1       I  1630 1905   *1A/E*                      3  EK 344 L 29NOV 2 DXBKUL HK1       3  2140 0835+1 *1A/E*                      4  MH 704 V 30NOV 3 KULMNL HK1       M  1245 1630   *1A/E*                      5  UA 184 Y 01DEC 4 MNLGUM HK1       1  2255 0440+1 *1A/E*                      6  UA 155 Y 02DEC 5 GUMTKK HK1          0820 1008   especially, the numbers (2,2,3,4,5) before KBLDXB, KULMNL.... The letters and numbers before time (I, 3, M, 1) *1A/E*? Is there a website or some other way to find out if I need a transit visa for a short stop in the UK on my way somewhere else? Ideally this should give me the answer for all nationalities, and take into account any other visas I may have. I would like to prove the following equality: $$k^{\phi(l)} + l^{\phi(k)} \equiv1\pmod{lk}$$if $\gcd(l,k)=1$. What methods can I use? Thank you for your help. Was Hogwarts named such because of a connection to warthogs? Was Hogwarts named 'Hogwarts' because of a connection to warthogs?  Or was it named for hogs and warts separately, or something else entirely? What is the cardinality of the set of all topologies on $\mathbb{R}$? This was  on Quora. I thought about it a little bit but didn't make much progress beyond some obvious upper and lower bounds. The answer probably depends on AC and perhaps also GCH or other axioms. A quick search also failed to provide answers. Why didn't Harry Potter tell Aunt Petunia he was rich to improve how he was treated by Dursleys? This is a follow-up question to   One reason Aunt Petunia mistreated Harry was that she did not know he was rich. If she knew, she would naturally have treated this golden goose nicely. Her retirement would be secured if Harry financially supported her in old age.  Why didn't Harry tell Aunt Petunia he was rich? Surely every boy wants to be treated nicely by his family. Category Theory textbook (learning through guided discovery Dummit and Foote) What's the single-word for "left or right handed"? 'Male'/'female' is to 'gender' as 'left-handed'/'right-handed 'is to...?  Is there a word to describe this? For example, if I ask a guy     What's your ____?   It should mean I'm asking whether he's left or right-handed.  Another example could be     Our designs are not biased  against your ____.   Basically, I'm looking for something that means the state of being left- or right-handed which could be used analogously as gender.  EDIT: Sorry for the delay in the edit, but I was tied up. There are some points I'd like to clarify:   I'm not looking for a way to paraphrase my questions. I'm looking for a single word. I know people normally ask something along the lines of "Are you left-handed or not?" People also ask "Are you afraid of the dark?" instead of "Are you scotophobiac?". The word for it,  still exists, right? It has been pointed out that I should go with Our designs are not biased against left-handed people as that is what I mean. But that is not necessarily what I mean.    For example, let's say there is a washbasin with the tap on the right. Clearly, it's biased against lefties. Sometimes, you come across a washbasin with a tap on the left. (The logic being: you use your left hand to turn the tap as your right one's dirty). But, your right hand might not always be dirty, in which case, it's biased against righties.  A washbasin with the tap on the center is, then, handedness-blind or chirality-blind, if you will. (I foresee that some would dwell on Our designs are symmetrical. Please don't.)  I'm looking for a term that would be applicable here, as well as in the 1st example.  My favorite so far is chirality, suggested by Dan Bron in a comment (with 25 upvotes!) But, I'm reluctant to use it because there's no hard proof it's used in that sense  If we are talking about male-female, gender works perfectly. What's your gender? and Our designs aren't biased against your gender. , both work perfectly here.  Sorry for the late edit again. If the consensus is that I rollback, I will. Let me know in the comments. Is there any formula for number of divisors of $a \times b$? Let $a$ and $b$ be two numbers,    Number of divisors of $a$ is $n_1$; Number of divisors of $b$ is $n_2$;    How to find the number of divisors $N$ of product $a \times b$ by using known number of divisors of factors $n_1$ and $n_2$?  If $a = 20$ and $b = 21$, then $n_1 = 6$ (number of divisors of $a$), $n_2 = 4$ (number of divisors of $b$. Then $a \times b = 420$ and $N = 32$ (number of divisors of $a \times b$).  Is there a formula to find $N$ in terms of $n_1$ and $n_2$? Following discussion , what constitutes a weapon damage die?  Is it any damage die dealt by the weapon? For example, consider a  longsword.     While the sword is ablaze, it deals an extra 2d6 fire damage to any target it hits.   What are the weapon damage dice? Just the 1d8 from the longsword? Or do the 2d6 Fire damage also count? How to take mysqldump with Generated column? I am getting below error while importing the dump,     ERROR 3105 (HY000) at line 82: The value specified for generated   column 'column_name' in table 'table_name' is not allowed.   When I describe the table with error, there are some generated columns in it.     option_type         | varchar(45)  | YES  | MUL | NULL    | VIRTUAL   GENERATED   What is the correct command to use when taking mysql dump for the database contains generated column?  MySQL server source and destination version:     mysqld Ver 5.7.26 for Linux on x86_64 (MySQL Community Server (GPL))   MariaDB mysqldump CLI version:     mysqldump Ver 10.17 Distrib 10.3.12-MariaDB, for Linux (x86_64) How iptables tables and chains are traversed I know linux has 3 built-in tables and each of them has its own chains as follow:  FILTER: PREROUTING, FORWARD, POSTROUTING  NAT: PREROUTING, INPUT, OUTPUT, POSTROUTING  MANGLE: PREROUTING, INPUT, FORWARD, OUTPUT, POSTROUTING  But I can't understand how they are traversed, in which order, if there is. For example, how are they traversed when:   I send a packet to a pc in my same local network when I send a packet to a pc in a different network when a gateway receives a packet and it has to forward it when I receive a packet destinated to me any other case (if any) Does the  tag position in HTML affects performance of the webpage? How can I determine if a used game is pirated? I have a DisplayPort based monitor, and a laptop with a DP out.  I recently got a second laptop with HDMI out, and went looking for a HDMI -> DP converter.  I was very surprised to find that such a thing effectively doesn't seem to exist.   and the  seem to imply that it's just not possible to go HDMI -> DP, without a very expensive converter box (not just an adaptor).  However, I can't find anything that explains why this is the case.  Is DP designed to be backwards compatible but can't interpret HDMI?  Is it a case of HDMI-quality signal not being high enough quality to be convertible?  Some other reason?  Note that this question is not looking for an adaptor - I'm looking for the underlying cause of the lack of them. What is the best way to explain how to choose between "its" and "it's"? Probably one of the most frequent grammar mistakes in the English language is:     The dog sat on it's mat.   Since spelling checkers don't catch it, and it is even logical, since you would correctly write:     The dog sat on Fluffy's mat.   What is the best way to explain to a learner of English how to choose between it's and its? Find $\space\ \begin{align*} \lim_ {x \to+\infty} \left [ \frac{\log_{2}(x-1)}{x}\right]   \end{align*}$.   After some minutes around this limit I did it this way:  $\log_{2}(x-1)=y \Leftrightarrow 2^y=x-1$  So,$\space x=2^y+1$.  When $x \to +\infty$,$\space y \to +\infty$ also. By substitution:  $\begin{align*} \lim_ {y \to+\infty} \left [ \frac{\log_{2}(2^y+1-1)}{2^y+1}\right]=\lim_ {y \to+\infty} \left [ \frac{\log_{2}(2^y)}{2^y+1}\right]=\end{align*}$  $\begin{align*}\lim_ {y \to+\infty} \left [ \frac{y}{2^y+1}\right]=\lim_ {y \to+\infty} \left [ \frac{1}{\frac{2^y+1}{y}}  \right]=\lim_ {y \to+\infty} \left [ \frac{1}{\frac{2^y}{y}+\frac{1}{y}}\right]= \frac{1}{+\infty+0}=0  \end{align*}$  Is this correct?Are there any other easy way to find this limit?Thanks How can I delete a symbolic link? I created a symlink using mklink.  Now I need to change it but I can't figure out how to delete it so I can recreate it correctly. How can I securely erase a hard drive? I'm planning on selling a USB external hard drive that currently contains an old Ubuntu installation with stored passwords and banking information.  How can I securely erase the drive before selling it? Height of an HTML select box (dropdown)