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Difference between no-cache and must-revalidate
...ably preferred by the user (better to have something stale than nothing at all). This is why must-revalidate is intended for critical transactions only.
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do { … } while (0) — what is it good for? [duplicate]
...#define FOO(x) { foo(x); bar(x); }
Using this in an if statement would require that you omit the semicolon, which is counterintuitive:
if (condition)
FOO(x)
else
...
If you define FOO like this:
#define FOO(x) do { foo(x); bar(x); } while (0)
then the following is syntactically corre...
Hash and salt passwords in C#
...
Actually this is kind of strange, with the string conversions - which the membership provider does to put them into config files. Hashes and salts are binary blobs, you don't need to convert them to strings unless you want to put...
How to add an auto-incrementing primary key to an existing table, in PostgreSQL?
...of PostgreSQL
In old versions of PostgreSQL (prior to 8.x?) you had to do all the dirty work. The following sequence of commands should do the trick:
ALTER TABLE test1 ADD COLUMN id INTEGER;
CREATE SEQUENCE test_id_seq OWNED BY test1.id;
ALTER TABLE test ALTER COLUMN id SET DEFAULT nextval('...
How do I get a background location update every n minutes in my iOS application?
...d with UIApplication:beginBackgroundTaskWithExpirationHandler:
When n is smaller than UIApplication:backgroundTimeRemaining it will work just fine. When n is larger, the location manager should be enabled (and disabled) again before there is no time remaining to avoid the background task being kille...
How do I parse a string to a float or int?
...ently imperfect for representing decimals. For more, see stackoverflow.com/q/21895756/931277
– dokkaebi
Aug 18 '17 at 21:44
20
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Android phone orientation overview including compass
...
Roll is a function of gravity, a 90 degree roll puts all of gravity into the x register.
Pitch is the same, a 90 degree pitch up puts all of the component of gravity into the y register.
Yaw / Heading / azimuth has no effect on gravity, it is ALWAYS at right angles to gravity...
How to export all data from table to an insertable sql format?
I have a Table (call it A_table ) in a database (call it A_db ) in Microsoft SQL Server Management Studio, and there are 10 rows.
...
Android Spinner: Get the selected item change event
... answered Nov 11 '09 at 10:50
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Meaning of $? (dollar question mark) in shell scripts
...ure.
Hence when scripting; I tend to use the following syntax
if [ $? -eq 0 ]; then
# do something
else
# do something else
fi
The comparison is to be done on equals to 0 or not equals 0.
** Update Based on the comment: Ideally, you should not use the above code block for comparison, refer t...