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What is the difference between ${var}, “$var”, and “${var}” in the Bash shell?
...bar', so loop runs once and
done # prints nothing (actually "")
var="foo bar"
for i in "${var}bar"; do # Expands to 'for i in "foo barbar"; do...'
echo $i # so runs the loop once
done
# foo barbar
Note that "${var}bar" in the second example above could also ...
Where is Python's sys.path initialized from?
...
"Initialized from the environment variable PYTHONPATH, plus an installation-dependent default"
-- http://docs.python.org/library/sys.html#sys.path
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GSON - Date format
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This won't really work at all. There is no date type in JSON. I would recommend to serialize to ISO8601 back and forth (for format agnostics and JS compat). Consider that you have to know which fields contain dates.
...
Mac OSX Lion DNS lookup order [closed]
... that file very light.
One advantage of running something like dnsmasq locally (besides the significant performance boost) is that you can redirect whole top-level domains back to your local machine. This allows you to have the whole *.dev namespace for development (for instance), without having to...
Include headers when using SELECT INTO OUTFILE?
...yourself. Something like:
SELECT 'ColName1', 'ColName2', 'ColName3'
UNION ALL
SELECT ColName1, ColName2, ColName3
FROM YourTable
INTO OUTFILE '/path/outfile'
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How to show line number when executing bash script
...ly executing.
If you need to know the line number where the function was called, try $BASH_LINENO. Note that this variable is an array.
For example:
#!/bin/bash
function log() {
echo "LINENO: ${LINENO}"
echo "BASH_LINENO: ${BASH_LINENO[*]}"
}
function foo() {
log "$@"
}
foo ...
How do you run a single query through mysql from the command line?
...ybyte Assuming Linux: Insinde doublequotes the asterisk * gets expanded to all files in the current directory, while this expansion does not happen in singlequotes, thats the reason why. Doublequotes will work for quesries without the *.
– NobbZ
Apr 3 '18 at 7:...
Animate the transition between fragments
...urse animate the translationX, translationY, x, and y properties, but generally slides involve animating content to and from off-screen. As far as I know there aren't any transition properties that use relative values. However, this doesn't prevent you from writing them yourself. Remember that prope...
Passing multiple error classes to ruby's rescue clause in a DRY fashion
...ne it in some other class, you have to refer to it with its namespace. Actually, it does not have to be a constant.
Splat Operator
The splat operator * "unpacks" an array in its position so that
rescue *EXCEPTIONS
means the same as
rescue FooException, BarException
You can also use it withi...
Test if something is not undefined in JavaScript
...eryone seems to think it is). If you want to, you could create a variable called undefined and then this check will be incorrect. The only correct way is to check (typeof myVar !== 'undefined').
– BadHorsie
Jun 20 '16 at 14:12
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