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Rails has_and_belongs_to_many migration
I have two models restaurant and user that I want to perform a has_and_belongs_to_many relationship.
4 Answers
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How to best display in Terminal a MySQL SELECT returning too many fields?
...minate the query with \G in place of ;. For example:
SELECT * FROM sometable\G
This query displays the rows vertically, like this:
*************************** 1. row ***************************
Host: localhost
Db: mydatabase1
User: myuser1
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How to convert a string to lower case in Bash?
Is there a way in bash to convert a string into a lower case string?
20 Answers
20
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Regular expression to match URLs in Java
I use RegexBuddy while working with regular expressions. From its library I copied the regular expression to match URLs. I tested successfully within RegexBuddy. However, when I copied it as Java String flavor and pasted it into Java code, it does not work. The following class prints false :
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Accessing nested JavaScript objects and arays by string path
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I just made this based on some similar code I already had, it appears to work:
Object.byString = function(o, s) {
s = s.replace(/\[(\w+)\]/g, '.$1'); // convert indexes to properties
s = s.replace(/^\./, ''); // strip a lea...
How to replace a string in multiple files in linux command line
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cd /path/to/your/folder
sed -i 's/foo/bar/g' *
Occurrences of "foo" will be replaced with "bar".
On BSD systems like macOS, you need to provide a backup extension like -i '.bak' or else "risk corruption or partial content" per the manpage.
cd /path/to/your/fo...
Are 2^n and n*2^n in the same time complexity?
Resources I've found on time complexity are unclear about when it is okay to ignore terms in a time complexity equation, specifically with non-polynomial examples.
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How to remove all line breaks from a string
I have a text in a textarea and I read it out using the .value attribute.
16 Answers
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How to grep (search) committed code in the Git history
..."Argument list too long" error.
If you want to limit the search to some subtree (for instance, "lib/util"), you will need to pass that to the rev-list subcommand and grep as well:
git grep <regexp> $(git rev-list --all -- lib/util) -- lib/util
This will grep through all your commit text fo...
Context switches much slower in new linux kernels
We are looking to upgrade the OS on our servers from Ubuntu 10.04 LTS to Ubuntu 12.04 LTS. Unfortunately, it seems that the latency to run a thread that has become runnable has significantly increased from the 2.6 kernel to the 3.2 kernel. In fact the latency numbers we are getting are hard to belie...