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Identify if a string is a number
... Function will return true if I pass string as "-123" or "+123". I Understand that integer has positive and negative values. But If this string is coming from user entered textbox then it should return false.
– user2323308
Aug 28 '13 at 13:58
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What is the best way to count “find” results?
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find <expr> -type f -printf '.' | wc -c
It will be more reliable and faster than counting the lines.
Note that I use the find's printf, not an external command.
Let's bench a bit :
$ ls -1
a
e
l
ll.sh
r
t
y
z
My snippet benchmark :
$ time find -type f -printf '.' | wc -c
8
real ...
Rails 3 - can't install pg gem
...g= 'PATH_TO_YOUR_PG_CONFIG'
If you are not sure where your pg_config is, and assuming you are on Linux or Mac, you can run the following command:
which pg_config
Your pg-config can be in different locations depending on how you installed postgres.
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In Bash, how to add “Are you sure [Y/n]” to any command or alias?
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These are more compact and versatile forms of Hamish's answer. They handle any mixture of upper and lower case letters:
read -r -p "Are you sure? [y/N] " response
case "$response" in
[yY][eE][sS]|[yY])
do_something
;;
*)
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Python glob multiple filetypes
....glob in python to get a list of multiple file types such as .txt, .mdown, and .markdown? Right now I have something like this:
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Python Dictionary Comprehension
...to add keys to an existing dictionary. Also, you have to specify the keys and values, although of course you can specify a dummy value if you like.
>>> d = {n: n**2 for n in range(5)}
>>> print d
{0: 0, 1: 1, 2: 4, 3: 9, 4: 16}
If you want to set them all to True:
>>>...
Programmatically find the number of cores on a machine
...;sysinfo);
int numCPU = sysinfo.dwNumberOfProcessors;
Linux, Solaris, AIX and Mac OS X >=10.4 (i.e. Tiger onwards)
int numCPU = sysconf(_SC_NPROCESSORS_ONLN);
FreeBSD, MacOS X, NetBSD, OpenBSD, etc.
int mib[4];
int numCPU;
std::size_t len = sizeof(numCPU);
/* set the mib for hw.ncpu */
mib[...
What does multicore assembly language look like?
...that's needed is software support for each thread to set up its own tables and messaging queues. The OS uses those to do the actual multi-threaded scheduling.
As far as the actual assembly is concerned, as Nicholas wrote, there's no difference between the assemblies for a single threaded or multi ...
How to create Drawable from resource
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As of API version 21 this method is deprecated and you should be replaced by: Drawable drawable = ResourcesCompat.getDrawable(getResources(), page.getImageId(), null);
– Boren
Apr 14 '15 at 23:07
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Where does the iPhone Simulator store its data?
I have a SQLite DB that I'm using to store app data, and I could do with taking a look inside it to debug a problem I'm having - but where does the iPhone Simulator store its data, typically?
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