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How do I test if a variable is a number in Bash?
... the regex appropriately; for instance:
^[0-9]+([.][0-9]+)?$
...or, to handle numbers with a sign:
^[+-]?[0-9]+([.][0-9]+)?$
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Which is more correct: … OR …
Are both <h1><a ...> ... </a></h1> and <a ...><h1> ... </h1></a> valid HTML, or is only one correct? If they are both correct, do they differ in meaning?
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How to convert R Markdown to PDF?
I've previously asked about the commands for converting R Markdown to HTML .
8 Answers
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Indenting #defines
...re-ANSI C preprocessor did not allow for space between the start of a line and the "#" character; the leading "#" had to always be placed in the first column.
Pre-ANSI C compilers are non-existent these days. Use which ever style (space before "#" or space between "#" and the identifier) you prefer...
Return a `struct` from a function in C
...ame as any built-in type for purposes of parameter passing, return values, and assignment.
Here's a simple demonstration program that does all three - passes a structure as a parameter, returns a structure from a function, and uses structures in assignment statements:
#include <stdio.h>
str...
How was the first compiler written?
I heard about the chicken and the egg and bootstrapping. I have a few questions.
6 Answers
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Custom Compiler Warnings
... compiler warnings telling you that the object/method/property is obsolete and somthing else should be used. I'm currently working on a project that requires a lot of refactoring an ex-employees code. I want to write a custom attribute that I can use to mark methods or properties that will generate ...
How do I turn a String into a InputStreamReader in java?
.... That wrong version number is especially weird as Java 1.4 introduced NIO and it makes little sense to introduce an API and its conceptional successor within the same version.
– Holger
Mar 31 '15 at 11:00
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Can I use jQuery with Node.js?
...his returns require("...").env is not a function.
– Banderi
May 28 '17 at 2:41
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@Banderi same wi...
How to change the order of DataFrame columns?
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incase you get "cannot concatenate 'str' and 'list' objects" make sure you [] the str value in cols: cols = [cols[7]] + cols[:7] + cols[8:]
– moeabdol
Jan 9 '15 at 16:59
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