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leading zeros in rails
...using a given padding character.
str.rjust(integer, padstr=' ') → new_str
If integer is greater than the length of str, returns a new String of length integer with str right justified and padded with padstr; otherwise, returns str.
some_int = 5
some_int.to_s.rjust(2, '0') # => '05'
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Get the IP address of the machine
...hould be the same below.
I've done a quick example below which will print all of the machine's IPv4 address, (you should also check the getifaddrs was successful ie returns 0).
I've updated it show IPv6 addresses too.
#include <stdio.h>
#include <sys/types.h>
#include <ifaddr...
Check for internet connection availability in Swift
...unc isConnectedToNetwork() -> Bool {
var zeroAddress = sockaddr_in(sin_len: 0, sin_family: 0, sin_port: 0, sin_addr: in_addr(s_addr: 0), sin_zero: (0, 0, 0, 0, 0, 0, 0, 0))
zeroAddress.sin_len = UInt8(sizeofValue(zeroAddress))
zeroAddress.sin_family = sa_family_t(AF_INET)...
How to check if there exists a process with a given pid in Python?
... if the pid is not running, and do nothing otherwise.
import os
def check_pid(pid):
""" Check For the existence of a unix pid. """
try:
os.kill(pid, 0)
except OSError:
return False
else:
return True
...
Pure virtual function with implementation
...e type can still define an implementation. A derived class can explicitly call the base class implementation (if access permissions allow it) by using a fully-scoped name (by calling A::f() in your example - if A::f() were public or protected). Something like:
class B : public A {
virtual voi...
Can table columns with a Foreign Key be NULL?
...d Mar 2 '10 at 21:37
Daniel VassalloDaniel Vassallo
301k6666 gold badges475475 silver badges424424 bronze badges
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How to get device make and model on iOS?
... if I have an iPhone 3GS vs. and iPhone 4 vs. an iPhone 4S (in actuality, all I really want to do is determine if I have a 3G or not, because I'm doing fairly graphics intensive stuff) .
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How do I remove/delete a folder that is not empty?
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This doesn't work for me: Traceback (most recent call last): File "foo.py", line 31, in <module> shutil.rmtree(thistestdir) File "/usr/lib/python2.6/shutil.py", line 225, in rmtree onerror(os.rmdir, path, sys.exc_info()) File "/usr/lib/python2.6/shutil.py...
How to get scrollbar position with Javascript?
...roll position isn't set on document.body in most modern browsers - it's usually set on document.documentElement now. See bugs.chromium.org/p/chromium/issues/detail?id=157855 for Chrome's transition.
– fzzfzzfzz
May 3 '18 at 15:51
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More elegant “ps aux | grep -v grep”
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brilliant hack (I think I should call it that, since the aux / grep authors probably did not think of this scenario.)
– Michael Trouw
Apr 12 '16 at 14:12
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