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An example of how to use getopts in bash
...pecify strength, either 45 or 90.
h | *) # Display help.
$ ./foo.sh -s 123 -p any_string
Strength needs to be either 45 or 90, 123 found instead.
p is any_string
$ ./foo.sh -s 90 -p any_string
Strength is 90.
p is any_string
See: Small getopts tutorial at Bash Hackers Wiki
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Apply a function to every row of a matrix or a data frame
Suppose I have a n by 2 matrix and a function that takes a 2-vector as one of its arguments. I would like to apply the function to each row of the matrix and get a n-vector. How to do this in R?
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Ruby, remove last N characters from a string?
...diomatic (and I'd argue, even more readable than other answers here):
'abc123'.delete_suffix('123') # => "abc"
'abc123'.delete_suffix!('123') # => "abc"
It's even significantly faster (almost 40% with the bang method) than the top answer. Here's the result of the same benchmark:
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How can I convert a string to a number in Perl?
...
This is a simple solution:
Example 1
my $var1 = "123abc";
print $var1 + 0;
Result
123
Example 2
my $var2 = "abc123";
print $var2 + 0;
Result
0
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Removing all non-numeric characters from string in Python
... this is the most efficient way, but:
>>> ''.join(c for c in "abc123def456" if c.isdigit())
'123456'
The ''.join part means to combine all the resulting characters together without any characters in between. Then the rest of it is a list comprehension, where (as you can probably guess) ...
rsync error: failed to set times on “/foo/bar”: Operation not permitted
...X) system.
A solution to the issue is to set adequate owner on the remote site.
Since this answer has been voted, and therefore has been hopefully useful to someone, I'm extending it to make it clearer.
The reason why this happens is that rsync is probably trying to set an arbitrary modification ...
Test whether string is a valid integer
...of "+" (e.g. +30) which obviously is an integer.
Results:
$ int_check.sh 123
123 is an integer !!
$ int_check.sh 123+
ERROR: first parameter must be an integer.
$ int_check.sh -123
-123 is an integer !!
$ int_check.sh +30
+30 is an integer !!
$ int_check.sh -123c
ERROR: first parameter must be...
How can I pad a String in Java?
...*chars
Display '*' for characters of password:
String password = "secret123";
String padded = String.format("%"+password.length()+"s", "").replace(' ', '*');
output has the same length as the password string:
secret123
*********
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Natural Sort Order in C#
...swer. In any case, you're free to provide a better answer; that's how this site works.
– Greg Beech
Jul 30 '12 at 7:45
6
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Android - implementing startForeground for a service?
...recent versions of Android. This is how i solved it:
Activity:
override fun onCreate(savedInstanceState: Bundle?) {
val intent = Intent(this, BackgroundService::class.java)
if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.O) {
startForegroundService(intent)
} else {
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