Recent questions tagged c

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Consider the following line of code: while((n = read(STDIN_FILENO, buff, BUFSIZ)) > 0) As per my ... times the while loop will iterate? See Question&Answers more detail:os...

asked Oct 24, 2021 in Technique[技术] by 深蓝 (71.8m points)

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c - Performance of array of functions over if and switch statements

I am writing a very performance critical part of the code and I had this crazy idea about substituting case ... already, I wont bother. See Question&Answers more detail:os...

asked Oct 24, 2021 in Technique[技术] by 深蓝 (71.8m points)

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c - How can I get the nth character of a string?

I have a string, char* str = "HELLO" If I wanted to get just the E from that how would I do that? See Question&Answers more detail:os...

asked Oct 24, 2021 in Technique[技术] by 深蓝 (71.8m points)

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c - Setting an array to one value

Is there an easier way in C to set an array to one value than using a for loop and going setting each value one by one? See Question&Answers more detail:os...

asked Oct 24, 2021 in Technique[技术] by 深蓝 (71.8m points)

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c - Understanding htonl() and ntohl()

I am trying to use unix sockets to test sending some udp packets to localhost. It is my understanding that when ... free(file_buf); return 0; } See Question&Answers more detail:os...

asked Oct 24, 2021 in Technique[技术] by 深蓝 (71.8m points)

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c - How does printf handle its arguments?

How does printf handle its arguments? I know that in C# I can use params keyword to do something similar but I can't get it done in C ? See Question&Answers more detail:os...

asked Oct 24, 2021 in Technique[技术] by 深蓝 (71.8m points)

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c - storage size of ‘names’ isn’t known

I get this error while compiling this .c source file /INIT_SOURCE_BUILD/src/names_list.c:7: error: storage size ... ListElmt *element); #endif See Question&Answers more detail:os...

asked Oct 24, 2021 in Technique[技术] by 深蓝 (71.8m points)

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c - What is the default generator for CMake in Windows?

When running CMake on one PC, CMake generates NMake files by default. On another, it generates a Visual Studio ... and NMake files on another. See Question&Answers more detail:os...

asked Oct 24, 2021 in Technique[技术] by 深蓝 (71.8m points)

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c - Call to malloc failing in gdb session

I am trying to debug a C program and gdb is telling me there is a segfault on line 329 of a ... basic_block *)malloc(sizeof(basic_block)); See Question&Answers more detail:os...

asked Oct 24, 2021 in Technique[技术] by 深蓝 (71.8m points)

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c - Finding center of 2D triangle?

I've been given a struct for a 2D triangle with x and y coordinates, a rotation variable, and so on. From ... I am looking for is the centroid. See Question&Answers more detail:os...

asked Oct 24, 2021 in Technique[技术] by 深蓝 (71.8m points)

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c - Cannot find libcrypto library error

When i am trying to compile a C code which uses openssl 'crypto' library functions with comand line -lcrypto ... 1 exit status Many thanks See Question&Answers more detail:os...

asked Oct 24, 2021 in Technique[技术] by 深蓝 (71.8m points)

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c - Do parentheses make a difference when determining the size of an array?

The following program prints the same number twice on gcc 4.8.2: #include <stdio.h> int main() { ... operator, string literal as initializer). See Question&Answers more detail:os...

asked Oct 24, 2021 in Technique[技术] by 深蓝 (71.8m points)

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c - Why no switch on pointers?

For instance: #include <stdio.h> void why_cant_we_switch_him(void *ptr) { switch (ptr) { case NULL: printf("NULL! ... is probably too late now.) See Question&Answers more detail:os...

asked Oct 24, 2021 in Technique[技术] by 深蓝 (71.8m points)

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c - Whatever happened to the 'entry' keyword?

While cruising through my white book the other day, I noticed in the list of C keywords. entry is one of the ... the story on the entry keyword? See Question&Answers more detail:os...

asked Oct 24, 2021 in Technique[技术] by 深蓝 (71.8m points)

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c - freeing a null pointer

What happens inside memory if we try to free a pointer which is pointing to NULL? Is that ever valid? Why ... show any warning/error messages? See Question&Answers more detail:os...

asked Oct 24, 2021 in Technique[技术] by 深蓝 (71.8m points)

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c - Initialization discards qualifiers from pointer target type

I'm trying to print the list of a singly linked list that I referred to in link text. It works, but I do ... } I am using XCode. Any thoughts? See Question&Answers more detail:os...

asked Oct 24, 2021 in Technique[技术] by 深蓝 (71.8m points)

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c - What is the difference between ssize_t and ptrdiff_t?

The C standard (ISO/IEC 9899:2011 or 9899:1999) defines a type ptrdiff_t in <stddef.h>. The POSIX standard ( ... not the same as for ptrdiff_t? See Question&Answers more detail:os...

asked Oct 24, 2021 in Technique[技术] by 深蓝 (71.8m points)

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c - Are members of a structure allowed to be static ?

#include<stdio.h> struct str { static int a ; int b ; } s ; int main() { static int p , k ; ... in the structure and what is its significance ? See Question&Answers more detail:os...

asked Oct 24, 2021 in Technique[技术] by 深蓝 (71.8m points)

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c - How to use Shared Memory (IPC) in Android

I've already written a simple Shared Memory C program in Linux. How can I use Shared Memory (or should I call it ... me a step-by-step guide. See Question&Answers more detail:os...

asked Oct 24, 2021 in Technique[技术] by 深蓝 (71.8m points)

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c - Sockets - Using INADDR_ANY on client side

I recently ran into this blog post which describes a TCP server client using libev. The sever uses INADDR_ANY to ... ? Thanks for your answers! See Question&Answers more detail:os...

asked Oct 24, 2021 in Technique[技术] by 深蓝 (71.8m points)

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c - Benefits of declaring a function as "inline"?

Every time I read about the "inline" declaration in C it is mentioned that it is only a hint to the ... the compiler knowing better than me? See Question&Answers more detail:os...

asked Oct 24, 2021 in Technique[技术] by 深蓝 (71.8m points)

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c - Undefined symbols error when using a header file

I'm getting the following error and can't for the life of me figure out what I'm doing wrong. $ gcc ... Or am I missing something? Regards. See Question&Answers more detail:os...

asked Oct 24, 2021 in Technique[技术] by 深蓝 (71.8m points)

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c - enable/disable cache on intel 64bit machine: CD bit always set?

I'm trying to disable all level of cache for my machine Intel(R) Xeon(R) CPU E5-1650 v2 @ 3.50GHz in Xen. I ... that the CR0's CD bit is 0. See Question&Answers more detail:os...

asked Oct 24, 2021 in Technique[技术] by 深蓝 (71.8m points)

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c - Why doesn't free() zero out the memory prior to releasing it?

When we free() memory in C, why is that memory not filled with zero? Is there a good way to ensure this ... back to the operating system... See Question&Answers more detail:os...

asked Oct 24, 2021 in Technique[技术] by 深蓝 (71.8m points)

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c - volatile variables as argument to function

Having this code: typedef volatile int COUNT; COUNT functionOne( COUNT *number ); int functionTwo( int *number ); I ... (&count); return 0; } See Question&Answers more detail:os...

asked Oct 24, 2021 in Technique[技术] by 深蓝 (71.8m points)

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c - What version of Visual Studio and/or MinGW do I need to build extension modules for a given version of Python?

To put this question a different way, what version of Visual C++ was each official build of Python from python. ... available on some web site? See Question&Answers more detail:os...

asked Oct 24, 2021 in Technique[技术] by 深蓝 (71.8m points)

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c - Why use different a different tag and typedef for a struct?

In C code, I've seen the following: typedef struct SomeStructTag { // struct members } SomeStruct; I'm not ... it to a different type name? See Question&Answers more detail:os...

asked Oct 24, 2021 in Technique[技术] by 深蓝 (71.8m points)

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c - Bitwise operations and shifts

Im having some trouble understanding how and why this code works the way it does. My partner in this assignment finished ... )^x); return r; } See Question&Answers more detail:os...

asked Oct 24, 2021 in Technique[技术] by 深蓝 (71.8m points)

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