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What is the use case of noop [:] in bash?
...o" != "1" ]
then
#echo Success
fi
Which causes bash to give a syntax error:
line 4: syntax error near unexpected token `fi'
line 4: `fi'
Bash can't have empty blocks (WTF). So you add a no-op:
if [ "$foo" != "1" ]
then
#echo Success
:
fi
or you can use the no-op to comment out...
What does “The APR based Apache Tomcat Native library was not found” mean?
...
+1 I was getting this error (posted by OP) only under Eclipse, eventhough it was fixed when i run it standalone (of course, after adding the native lib.) Thanks for the tip on setting the system property!
– asgs
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What does DIM stand for in Visual Basic and BASIC?
What does DIM stand for in Visual Basic?
10 Answers
10
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Git: Correct way to change Active Branch in a bare repository?
I have a bare repository that's used as the central store for my project. All the developers do git clone <repo> to share with it. When they do the clone, they get a checkout of the master branch (unless they do git clone -n ) because repo.git/HEAD contains ref: refs/heads/master , mak...
Entity framework code-first null foreign key
I have a User < Country model. A user belongs to a country, but may not belong to any (null foreign key).
4 Answers
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How to create an empty file at the command line in Windows?
...one I use is basically the one by Nomad:
.>out.txt
It does give an error:
'.' is not recognized as an internal or external command
But this error is on stderr. And > only redirects stdout, where nothing have been produced.
Hence the creation of an empty file. The error message can be ...
iPhone OS: How do I create an NSDate for a specific date?
...TimeZone setDateFormat:@"MMM dd, yyyy"];
NSDate *theDate = nil;
NSError *error = nil;
if (![rfc3339TimestampFormatterWithTimeZone getObjectValue:&theDate forString:dateString range:nil error:&error]) {
NSLog(@"Date '%@' could not be parsed: %@", dateString, error);
}...
Swift class introspection & generics
...ft class I tried...
class MyClass {
}
let MyClassRef = MyClass.self
// ERROR :(
let my_obj = MyClassRef()
Hmm… the error says:
Playground execution failed: error: :16:1: error: constructing an object of class type 'X' with a metatype value requires an '@required' initializer
Y().me()
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What are some better ways to avoid the do-while(0); hack in C++?
...es something that can be solved with RAII. Maybe I should have said "issue error" or some such instead.
– Mats Petersson
Aug 29 '13 at 10:15
25
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Whether a variable is undefined [duplicate]
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if(undefinedVar) will throw an error, but if(someObj.undefinedProperty) will not. In the latter case, you can also skip typeof and use === undefined (or !==), without quotes.
– eyelidlessness
Sep 28 '09 at 8:56
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