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How can I convert a DateTime to the number of seconds since 1970?
...t a C# DateTime variable to Unix time, ie, the number of seconds since Jan 1st, 1970. It looks like a DateTime is actually implemented as the number of 'ticks' since Jan 1st, 0001.
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How to validate an email address in PHP
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How to get the primary IP address of the local machine on Linux and OS X? [closed]
...ould return me the primary (first) IP address of the localhost, other than 127.0.0.1
31 Answers
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Elastic Search: how to see the indexed data
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171
Probably the easiest way to explore your ElasticSearch cluster is to use elasticsearch-head.
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How to check if a string is a valid hex color representation?
...d support for 3-character HEX codes, use the following:
/^#([0-9A-F]{3}){1,2}$/i.test('#ABC')
The only difference here is that
[0-9A-F]{6}
is replaced with
([0-9A-F]{3}){1,2}
This means that instead of matching exactly 6 characters, it will match exactly 3 characters, but 1 or 2 times. Al...
Email Address Validation in Android on EditText [duplicate]
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edited Feb 21 at 13:14
milosmns
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an...
How to output only captured groups with sed?
...e output as well as specifying what you do want.
string='This is a sample 123 text and some 987 numbers'
echo "$string" | sed -rn 's/[^[:digit:]]*([[:digit:]]+)[^[:digit:]]+([[:digit:]]+)[^[:digit:]]*/\1 \2/p'
This says:
don't default to printing each line (-n)
exclude zero or more non-digits
i...
How to run crontab job every week on Sunday
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Convert column classes in data.table
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105
For a single column:
dtnew <- dt[, Quarter:=as.character(Quarter)]
str(dtnew)
Classes ‘...