Recent questions tagged C

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c - I want to convert an image into pencil sketch in OpenCV

I am trying to convert an image (from my hard drive) to a pencil sketch in OpenCV. I am using Visual Studio ... "); cvDestroyWindow("Output"); } 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 - casting pointer to array into pointer

Consider the following C code: int arr[2] = {0, 0}; int *ptr = (int*)&arr; ptr[0] = 5; printf(" ... ...but this is clearly a distinct question. 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 store and then print a 2d character/string array?

Suppose I have the words: tiger, lion, giraffe. How can I store it in a two dimensional char array using ... find a suitable answer on Google. 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 - Redirection inside call to execvp() not working

I've been implementing a small program that executes a given command using execvp(). It works fine when not using ... to use execvp()? 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 - Segmentation fault around strcpy?

I know that you will rap me over the knuckles but. Why does it make Segmentation fault char* cmd; strcpy( ... this segmentation fault. 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 - Removing elements from dynamic arrays

So, I have this: #include <stdio.h> #include <stdlib.h> #include <string.h> void remove_element(int* array, int ... test[16]); 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 - Function to check if input string is an integer or floating point number?

Is there a function in C to check if the input is an int, long int, or float? I know C has an isdigit ... string) and output a TRUE/FALSE value. 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 - ISO C90 forbids variable length array

I'm dynamically calculating the size of an array. Something like: void foo(size_t limit) { char buffer[limit * 14 + ... me. Is this a GCC bug? 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 could I achieve gotoxy() in gcc

I am using gcc in ubuntu.so, I compile and execute in terminal. But In a online programming contest, they ... , How could I achieve this? 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 - slow sparse matrix vector product (CSR) using open mp

I am trying to speed up a sparse matrix-vector product using open mp, the code is as follows: void zAx(double * ... large size may be my issue. 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 pass parameters to Linux system call?

I'm a college student studying OS. I'm trying to add my own system call in Linux kernel, and something is ... system call? Thank you in advance. 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 and cache behaviour

I read post C volatile variables and Cache Memory But i am confused. Question: whether OS will take care ... as _Uncached. Regards Learner 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 gcc -O1 optimization without specifying -O1

I know that -O1 automatically turns on certain flags. These flags can be turned on manually though. If I don't ... on to get -O1 optimization? 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 - clock() precision in time.h

I am trying to calculate the number of ticks a function uses to run and to do so an using the clock() ... systems like Windows & Mac OS. 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 read input of unknown length using fgets

How am I supposed to read long input using fgets(), I don't quite get it. I wrote this #include <stdio.h> ... ); free(input); 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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348 views

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c - Receiving power notifications (especially shutdown) on Mac OSX

I'm writing an application in C for the Mac (Leopard) that needs to do some work on receipt of power ... in advance for any help/tips! 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 - Pipe implementation

I am trying to implement a linux shell that supports piping. I have already done simple commands, commands running in ... doesn't work. 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 - Hardware performance counter APIs for Windows

I'd like to use hardware performance counter, specifically x86 CPUs to obtain cache misses or branch mis- ... performance counters on Windows? 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 remove a symbol from a shared object?

Using GCC, how can I remove a symbol from a shared object after I've created the shared object? If I ... now it returns: 000000000000063c T foo 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 - Testing equality between two __m128i variables

If I want to do a bitwise equality test between two __m128i variables, am I required to use an SSE ... SSE instruction should I use? 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 - NCurses Refresh

I have a small ncurse program I'm running, but the output doesn't seem to show up unless I stick the wrefresh() ... ); delwin(win); endwin(); } See Question&Answers more detail:os...

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

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555 views

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c - How to insert synthetic mouse events into X11 input queue

I've got an embedded device running Linux/X11 that is connected to a device that provides touch events over a USB ... ); return( FALSE ); } 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 - Best way to compare two int arrays of the same length?

what is the best way to compare int arrays b and c with a: int a[] = {0,1,0,0,1}; int b[] ... question I realise, thank you for your patience. 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 - Reaching EOF with fgets

I'm writing a function that perform some authentications actions. I have a file with all the user_id:password:flag ... me some tips or suggests? 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 - Is it possible to unpage all memory in Windows?

I have plenty of RAM, however, after starting and finishing a large number of processes, it seems that most ... unpage each process's memory? See Question&Answers more detail:os...

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

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382 views

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c - How to cross-compile for MIPS?

I have a DVB receiver (set-top box) similar like Dreambox and it has MIPS cpu It has embedded Linux and I can ... ? Where to get toolchain, SDK? See Question&Answers more detail:os...

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

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483 views

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c - Which initializer is appropriate for an int64_t?

I like to initialize my variables to some "dummy" value and have started to use int64_t and uint64_t. So far, ... within its bounds, of course)? 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 - Is there a way to detect that TCP socket has been closed by the remote peer, without reading from it?

First, a little background to explain the motivation: I'm working on a very simple select()-based TCP "mirror ... if such a function existed). See Question&Answers more detail:os...

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

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