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How can I match a string with a regex in Bash?
...ching in the second example. Inside [[ ]], the * is not expanded as it usually is, to match filenames in the current directory that match a pattern.Your example works, but it's really easy to over-generalize and mistakenly believe that * means to match anything in any context. It only works like t...
What's an easy way to read random line from a file in Unix command line?
...
You can use shuf:
shuf -n 1 $FILE
There is also a utility called rl. In Debian it's in the randomize-lines package that does exactly what you want, though not available in all distros. On its home page it actually recommends the use of shuf instead (which didn't exist when it was cr...
What is a regular expression which will match a valid domain name without a subdomain?
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This should match all cases I think: ^([a-z0-9])(([a-z0-9-]{1,61})?[a-z0-9]{1})?(\.[a-z0-9](([a-z0-9-]{1,61})?[a-z0-9]{1})?)?(\.[a-zA-Z]{2,4})+$
– transilvlad
May 16 '13 at 16:38
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Create space at the beginning of a UITextField
...but this is not the way. The reason you've to do it with a subclass is for all the edge cases. This code will probably crash before the subclass solution. But you are right that you shouldn't write code that is not strictly needed and can be provide by using the given libraries, but you shouldn't ab...
How can I perform a str_replace in JavaScript, replacing text in JavaScript?
...erf, you can have different levels of efficiency for creating a regex, but all of them are significantly slower than a simple string replace. The regex is slower because:
Fixed-string matches don't have backtracking, compilation steps, ranges, character classes, or a host of other features that ...
What is the difference between user and kernel modes in operating systems?
... CPU instruction and
reference any memory address. Kernel
mode is generally reserved for the
lowest-level, most trusted functions
of the operating system. Crashes in
kernel mode are catastrophic; they
will halt the entire PC.
User Mode
In User mode, the executing code has no abili...
Unmangling the result of std::type_info::name
... calling function. This should be relatively easy, standard C++ has a type_info class. This contains the name of the typeid'd class/function/etc. but it's mangled. It's not very useful. I.e. typeid(std::vector<int>).name() returns St6vectorIiSaIiEE .
...
Why is printing to stdout so slow? Can it be sped up?
...ing I decided to look into it and was quite surprised to find that almost all the time spent is waiting for the terminal to process the results.
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How can I pad an int with leading zeros when using cout
...ormatted output to a string (char* or char[]) not to console directly. Actually I am writing a function that returns formatted string
– shashwat
Dec 23 '12 at 9:32
14
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What exactly does an #if 0 … #endif block do?
...entire thing. And the #if 0s will nest with each other, like so:
#if 0
pre_foo();
#if 0
foo();
bar(x, y); /* x must not be NULL */
baz();
#endif
quux();
#endif
Although of course this can get a bit confusing and become a maintenance headache if not commented properly.
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