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Why do you need to put #!/bin/bash at the beginning of a script file?
I have made Bash scripts before and they all ran fine without #!/bin/bash at the beginning.
9 Answers
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Singletons vs. Application Context in Android?
Recalling this post enumerating several problems of using singletons
and having seen several examples of Android applications using singleton pattern, I wonder if it's a good idea to use Singletons instead of single instances shared through global application state (subclassing android.os.Applicat...
How to free memory in Java?
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Java uses managed memory, so the only way you can allocate memory is by using the new operator, and the only way you can deallocate memory is by relying on the garbage collector.
This memory management whitepaper (PDF) may help explain what's going on.
You can also call Sy...
Views vs Components in Ember.js
... and then implement their behavior using JavaScript? You can't do this actually with a Ember.View.
Ember.Component
That's exactly what components let you do. In fact, it's such a good idea that the W3C is currently working on the Custom Elements spec.
Ember's implementation of components tries to be...
MongoDB数据导出导入工具：mongoexport,mongoimport - 大数据 & AI - 清泛...
...个students集合，集合中数据如下：
> db.students.find()
{ "_id" : ObjectId("5031143350f2481577ea81e5"), "classid" : 1, "age" : 20, "name" : "kobe" }
{ "_id" : ObjectId("5031144a50f2481577ea81e6"), "classid" : 1, "age" : 23, "name" : "nash" }
{ "_id" : ObjectId("5031145a50f2481577ea81...
Knight's Shortest Path on Chessboard
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You have a graph here, where all available moves are connected (value=1), and unavailable moves are disconnected (value=0), the sparse matrix would be like:
(a1,b3)=1,
(a1,c2)=1,
.....
And the shortest path of two points in a graph can be found usin...
gdb fails with “Unable to find Mach task port for process-id” error
...h here: stackoverflow.com/a/10441587/305149
– Aneil Mallavarapu
Feb 10 '14 at 3:51
14
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How can I remove non-ASCII characters but leave periods and spaces using Python?
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You can filter all characters from the string that are not printable using string.printable, like this:
>>> s = "some\x00string. with\x15 funny characters"
>>> import string
>>> printable = set(string.printable)
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How to print without newline or space?
...to the end of the string:
print('.', end='')
To not add a space between all the function arguments you want to print:
print('a', 'b', 'c', sep='')
You can pass any string to either parameter, and you can use both parameters at the same time.
If you are having trouble with buffering, you can f...
How can I replace a newline (\n) using sed?
...ns not to do it on the last line as there should be one final newline).
Finally the substitution replaces every newline with a space on the pattern space (which is the whole file).
Here is cross-platform compatible syntax which works with BSD and OS X's sed (as per @Benjie comment):
sed -e ':a' -...