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How do I delete an exported environment variable?
... @RodrigoGurgel using echo won't show existing variable set to empty string or nul. to your point, though, a proper way to test for variable would be env | grep -e '^VARNAME='.
– Thomas
Feb 1 '19 at 14:22
...
How do I restrict a float value to only two places after the decimal point in C?
... just want to round the number for output purposes, then the "%.2f" format string is indeed the correct answer. However, if you actually want to round the floating point value for further computation, something like the following works:
#include <math.h>
float val = 37.777779;
float rounde...
How can I negate the return-value of a process?
...ns:
!(p4 labels | grep GIT_TAG_ON_A_BRANCH)
to check that the given string is not printed by 'p4 labels'.
This is problematic, because according to POSIX:
"If the pipeline begins with the reserved word ! and command1 is a subshell command, the application shall ensure that the ( o...
How to Set Variables in a Laravel Blade Template
... (for instance) an operator such as ==.
@if ($variable = 'any data, be it string, variable or OOP') @endif
Then you can use it anywhere you can use any other variable
{{ $variable }}
The only downside is your assignment will look like a mistake to someone not aware that you're doing this as a ...
How to delete last character from a string using jQuery?
How to delete last character from a string for instance in 123-4- when I delete 4 it should display 123- using jQuery .
...
INSERT with SELECT
...
22 and '22' should not matter to sql, but I put a string in case that the field is similar to an unique identifier.
– Dumitrescu Bogdan
Mar 22 '11 at 12:54
...
Many-to-many relationship with the same model in rails?
...schema for your posts:
create_table "posts", :force => true do |t|
t.string "name", :null => false
end
For any many-to-many relationship, you need a join table. Here's the schema for that:
create_table "post_connections", :force => true, :id => false do |t|
t.integer "post_a_id"...
Finding quaternion representing the rotation from one vector to another
...r you can still freely spin the result around it's axis? Do you know what extra information can typically be used to constrain this choice and make the problem well defined?
– Doug McClean
Oct 26 '13 at 2:07
...
Download a file with Android, and showing the progress in a ProgressDialog
...fy the UI thread from here
private class DownloadTask extends AsyncTask<String, Integer, String> {
private Context context;
private PowerManager.WakeLock mWakeLock;
public DownloadTask(Context context) {
this.context = context;
}
@Override
protected String do...
How did I get a value larger than 8 bits in size from an 8-bit integer?
...s extended to bit-width sizeof(int) . As I understand it, incrementing a char shouldn't ever be undefined behavior as long as sizeof(char) < sizeof(int) . But that doesn't explain how c is getting an impossible value. As an 8-bit integer, how can c hold values greater than its bit-width...