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Practical usage of setjmp and longjmp in C
Can anyone explain me where exactly setjmp() and longjmp() functions can be used practically in embedded programming? I know that these are for error handling. But I'd like to know some use cases.
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Different bash prompt for different vi editing mode?
...have a prompt that depends on the mode you are currently in (insert or command). How does one find out this editing mode?
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Can I assume (bool)true == (int)1 for any C++ compiler?
...are redundant. In your expression:
true == 1
Integral promotion applies and the bool value will be promoted to an int and this promotion must yield 1.
Reference: 4.7 [conv.integral] / 4: If the source type is bool... true is converted to one.
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Python executable not finding libpython shared library
I am installing Python 2.7 on CentOS 5. I built and installed Python as follows
9 Answers
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Force R not to use exponential notation (e.g. e+10)?
...a grey area. You need to recall that R will always invoke a print method, and these print methods listen to some options. Including 'scipen' -- a penalty for scientific display. From help(options):
‘scipen’: integer. A penalty to be applied when deciding to print
numeric value...
Extract month and year from a zoo::yearmon object
... "%m"))
[1] 3
> as.numeric(format(date1, "%Y"))
[1] 2012
See ?yearmon and ?strftime for details - the latter explains the placeholder characters you can use.
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What does %~dp0 mean, and how does it work?
I find %~dp0 very useful, and I use it a lot to make my batch files more portable.
7 Answers
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How to install latest version of git on CentOS 7.x/6.x
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You can use WANDisco's CentOS repository to install Git 2.x: for CentOS 6, for CentOS 7
Install WANDisco repo package:
yum install http://opensource.wandisco.com/centos/6/git/x86_64/wandisco-git-release-6-1.noarch.rpm
- or -
yum instal...
How do you change the size of figures drawn with matplotlib?
...figsize=(8, 6), ...) to change it's size etc. If you're using pyplot/pylab and show() to create a popup window, you need to call figure(num=1,...) before you plot anything - pyplot/pylab creates a figure as soon as you draw something, and the size of the popup appears to be fixed at this point.
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How do you round a floating point number in Perl?
...f perldoc -q round
Does Perl have a round() function? What about ceil() and floor()?
Trig functions?
Remember that int() merely truncates toward 0. For rounding to a certain number of digits, sprintf() or printf() is usually the easiest
route.
printf("%.3f", 3.1415926535); # prints 3...