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mongodb: insert if not exists
...-find-else-update block entirely. It will insert if the key doesn't exist and will update if it does.
Before:
{"key":"value", "key2":"Ohai."}
After:
{"key":"value", "key2":"value2", "key3":"value3"}
You can also specify what data you want to write:
data = {"$set":{"key2":"value2"}}
Now yo...
Quickly create a large file on a Linux system
...her answers is a good solution, but it is slow for this purpose. In Linux (and other POSIX systems), we have fallocate, which uses the desired space without having to actually writing to it, works with most modern disk based file systems, very fast:
For example:
fallocate -l 10G gentoo_root.img
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How do I convert a String object into a Hash object?
...en its string representation is "{:a=>#<Object:0x7f66b65cf4d0>}", and I can't use eval to turn it back into a hash because #<Object:0x7f66b65cf4d0> isn't valid Ruby syntax.
However, if all that's in the hash is strings, symbols, numbers, and arrays, it should work, because those have...
Big O of JavaScript arrays
Arrays in JavaScript are very easy to modify by adding and removing items. It somewhat masks the fact that most languages arrays are fixed-size, and require complex operations to resize. It seems that JavaScript makes it easy to write poorly performing array code. This leads to the question:
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I want to get Year, Month, Day, etc from Java Date to compare with Gregorian Calendar date in Java.
....add(Calendar.DAY_OF_MONTH, -48) to do day arithmetic on Calendar objects. And you can compare two Calendar objects using cal.compareTo(anotherCal).
– Florent Guillaume
Feb 27 '12 at 23:55
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Use find command but exclude files in two directories
...t to find files that end with _peaks.bed , but exclude files in the tmp and scripts folders.
6 Answers
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Read input from console in Ruby?
...ing like that?
Update
Kernel.gets tries to read the params found in ARGV and only asks to console if not ARGV found. To force to read from console even if ARGV is not empty use STDIN.gets
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Wget output document and headers to STDOUT
I'm trying to output document body and its headers to stdout with wget by wget -S -O - http://google.com
5 Answers
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SQL to determine minimum sequential days of access?
...n user has accessed a website (in a 24 hour UTC period). It has many thousands of records, but only one record per day per user. If the user has not accessed the website for that day, no record will be generated.
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Is there a way of setting culture for a whole application? All current threads and new threads?
...here a way of setting culture for a whole application? All current threads and new threads?
10 Answers
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