Questions tagged [c]
C is a general-purpose programming language used for system programming (OS and embedded), libraries, games, and cross-platform. This tag should be used with general questions concerning the C language, as defined in the ISO 9899 standard (the latest version, 9899:2018, unless otherwise specified — also tag version-specific requests with c89, c99, c11, etc.). C is distinct from C++, and it should not be combined with the C++ tag without a specific reason.
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What is the '-->' operator in C/C++?
After reading Hidden Features and Dark Corners of C++/STL on comp.lang.c++.moderated, I was completely surprised that the following snippet compiled and worked in both Visual Studio 2008 and G++ 4.4. ...
3383
votes
12
answers
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Improve INSERT-per-second performance of SQLite
Optimizing SQLite is tricky. Bulk-insert performance of a C application can vary from 85 inserts per second to over 96,000 inserts per second!
Background: We are using SQLite as part of a desktop ...
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What is the difference between #include <filename> and #include "filename"?
What is the difference between using angle brackets and quotes in an include directive?
#include <filename>
#include "filename"
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Should I cast the result of malloc (in C)?
In this question, someone suggested in a comment that I should not cast the result of malloc. i.e., I should do this:
int *sieve = malloc(sizeof(*sieve) * length);
rather than:
int *sieve = (int *) ...
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What does the ??!??! operator do in C?
I saw a line of C that looked like this:
!ErrorHasOccured() ??!??! HandleError();
It compiled correctly and seems to run ok. It seems like it's checking if an error has occurred, and if it has, it ...
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What is the effect of extern "C" in C++?
What exactly does putting extern "C" into C++ code do?
For example:
extern "C" {
void foo();
}
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What is the difference between const int*, const int * const, and int * const?
I always mess up how to use const int *, const int * const, and int * const correctly. Is there a set of rules defining what you can and cannot do?
I want to know all the do's and all don'ts in terms ...
ultraman
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With arrays, why is it the case that a[5] == 5[a]?
As Joel points out in Stack Overflow podcast #34, in C Programming Language (aka: K & R), there is mention of this property of arrays in C: a[5] == 5[a]
Joel says that it's because of pointer ...
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What is ':-!!' in C?
I bumped into this strange macro code in /usr/include/linux/kernel.h:
/* Force a compilation error if condition is true, but also produce a
result (of value 0 and type size_t), so the expression ...
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Is < faster than <=?
Is if (a < 901) faster than if (a <= 900)?
Not exactly as in this simple example, but there are slight performance changes on loop complex code. I suppose this has to do something with generated ...
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Compiling an application for use in highly radioactive environments
We are compiling an embedded C++ application that is deployed in a shielded device in an environment bombarded with ionizing radiation. We are using GCC and cross-compiling for ARM. When deployed, our ...
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How do function pointers in C work?
I had some experience lately with function pointers in C.
So going on with the tradition of answering your own questions, I decided to make a small summary of the very basics, for those who need a ...
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22
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What does "static" mean in C?
I've seen the word static used in different places in C code; is this like a static function/class in C# (where the implementation is shared across objects)?
David
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How do I determine the size of my array in C?
How do I determine the size of my array in C?
That is, the number of elements the array can hold?
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