Recent questions tagged C

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c - clearing a small integer array: memset vs. for loop

There are two ways to zero out an integer/float array: memset(array, 0, sizeof(int)*arraysize); or: for (int i=0; i < ... [3] = 0; array[4] = 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 to get Selected Text from select2 when using <input>

I am using the select2 control, loading data via ajax. This requires the use of the <input type=hidden..> ... select2 controls on the page. 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 - error: Libtool library used but 'LIBTOOL' is undefined

I am trying to automake the OrientDb C++ library, but getting some errors. Makefile.am:10: error: Libtool ... /share/libtool aclocal -I . 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 - OpenSSL using EVP vs. algorithm API for symmetric crypto

Hi i have installed openssl on my linux machine and going through the header files and documentation (which is highly ... if i am being naive 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 cast sockaddr_storage and avoid breaking strict-aliasing rules

I'm using Beej's Guide to Networking and came across an aliasing issue. He proposes a function to return either ... , I'd much appreciate it. 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 - Can endianness refer to bits order in a byte?

I'm reading "Learning Core Audio: A Hands-On Guide to Audio Programming for Mac and iOS" by Chris Adamson ... Or did I misunderstood his point? 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 is writing to memory much slower than reading it?

Here's a simple memset bandwidth benchmark: #include <stdio.h> #include <stdlib.h> #include <string.h> #include <time.h ... (char)c; return s; } 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 the purpose of some assembly statements

I am trying to understand some assembly code and managed to finish most of it except a few lines. I am able to ... lea -0x4(%ecx),%esp ; ?? 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 do spell checkers work?

I need to implement a spell checker in C. Basically, I need all the standard operations... I need to be able ... don't know where to begin. 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 shared libraries use the same heap as the application?

Say I have an application in Linux that uses shared libraries (.so files). My question is whether the code ... for those shared object files. 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 - Excess elements of scalar initializer for pointer to array of ints

I'm working on an exercise in K&R (ex. 5-9) and I was trying to convert the original program's 2D array of static ... (int (*daytab)[13]) {...} 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's the purpose of this [1] at the end of struct declaration?

I was snooping through my MSP430 microcontroller's header files, and I ran into this in <setjmp.h>: /* r3 does ... it's used for. Any ideas? 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 - Record RTSP stream with FFmpeg libavformat

I'm trying to record RTSP stream from Axis camera with FFmpeg libavformat. I can grab video from files and ... test.avi Thanks for any advice 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 - Writing a Python extension in Go (Golang)

I currently use Cython to link C and Python, and get speedup in slow bits of python code. However, I' ... without having to reinvent any wheels? 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 - Mmh, who are you PRIu64?

I am new to C and I am confronted with: #include <stdio.h> #include <inttypes.h> int main(void) { uint64_t ... about this? Thanks a lot! torr 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 Struct Semantics

Is it sufficient to declare an instance of a structure-typed variable as volatile (if its fields are ... for structure-typed variables. 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 does %d stand for Integer?

I know this doesn't sound productive, but I'm looking for a way to remember all of the formatting codes ... %i already taken by something else? 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 - Conflict between a Stanford tutorial and GCC

According to this movie (around minute 38), if I have two functions with the same local vars, they will use the ... xchg ax,ax 804844f: 90 nop 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 - A Guide for Creating your own Library for Cocoa(touch) development

I'm currently using a lot of the same subclassed objects with custom methods. It would be more convenient to ... using my own static library? 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 - Scope of malloc used in a function

When a function returns, is the memory allocated via malloc freed? Or can it still be accessed in the main() ... be accessed by main() here? See Question&Answers more detail:os...

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

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356 views

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c - Is ((void*)0) a null pointer constant?

I'm reading this blog post and under the section Null pointer constants and parenthesized expressions the author ... a null pointer constant? 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 - error: unknown type name ‘bool’

I downloaded the source code and wanted to compile the file of scanner. It produces this error: [meepo@localhost cs143- ... do I fix the error? 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 - When to use const void*?

I have this very simple test function that I'm using to figure out what's going on with const qualifier. ... at which vpointer is pointing? 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 - One-way flight trip problem

You are going on a one-way indirect flight trip that includes billions an unknown very large number of ... another more effective method. 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 - Unix Domain Socket: Using datagram communication between one server process and several client processes

I would like to establish an IPC connection between several processes on Linux. I have never used UNIX sockets ... any comments / solutions! See Question&Answers more detail:os...

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

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584 views

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c - Using make with -j4 or -j8

I have 4 processors and am compiling a processor-hungry application. I read that using make with the -j4 ... of making for multiple processors? 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's the difference between GNU99 and C99 (Clang)?

I have saw the compiler option GNU99 and C99. What's the difference of them? Any detail documentation? (Clang, Xcode, Mac OS X) 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 trigger SIGUSR1 and SIGUSR2?

I'm getting acquainted with signals in C. I can't figure out what kind of signals SIGUSR1 and SIGUSR2 are ... anyone please explain it to 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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