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Grep characters before and after match?
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What's the significance of the first number in the curly-bracketed pairs? Like the 0s in "grep -E -o ".{0,5}test_pattern.{0,5}" test.txt "?
– Lew Rockwell Fan
Jun 23 '17 at 2:28
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String concatenation does not work in SQLite
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field1 || field2 returns null if one of the fields is null. One might want to do ifnull(field1,'')||ifnull(field2,''). That will give you a response if one or both fields are null. Then you get to figure out what you want to do if both were null.
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How to safely open/close files in python 2.4
...try:
# do stuff with f
finally:
f.close()
This ensures that even if # do stuff with f raises an exception, f will still be closed properly.
Note that open should appear outside of the try. If open itself raises an exception, the file wasn't opened and does not need to be closed. Also, if ...
Change SQLite default settings
...n
And .headers on , we can see the header of tables.
But I want to know if there is any way make the two default settings?
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How to generate service reference with only physical wsdl file
...s: box, enter the physical path (C:\test\project....) of the downloaded/Modified wsdl.
Hit Go
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Implicit type conversion rules in C++ operators
...C++ operators (for POD types) always act on objects of the same type.
Thus if they are not the same one will be promoted to match the other.
The type of the result of the operation is the same as operands (after conversion).
If either is long double the other is promoted to long...
How to access array elements in a Django template?
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Remember that the dot notation in a Django template is used for four different notations in Python. In a template, foo.bar can mean any of:
foo[bar] # dictionary lookup
foo.bar # attribute lookup
foo.bar() # method call
foo[bar] # list-index lookup
It tries them in t...
How to get the command line args passed to a running process on unix/linux systems?
.../<pid> on Linux, just have a look.
On other Unixes things might be different. The ps command will work everywhere, the /proc stuff is OS specific. For example on AIX there is no cmdline in /proc.
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Using a bitmask in C#
....None;
Logical bitwise combinations can be tough to remember, so I make life easier on myself with a FlagsHelper class*:
// The casts to object in the below code are an unfortunate necessity due to
// C#'s restriction against a where T : Enum constraint. (There are ways around
// this, but they'r...
How to input a regex in string.replace?
... to be escaped (i.e. with a backslash placed in front - and the rules are different inside and outside character classes.) There is an excellent online tutorial at: www.regular-expressions.info. The time you spend there will pay for itself many times over. Happy regexing!
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