Recent questions tagged C

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c - Why does #define INVALID_VALUE -999; give a syntax error when used?

I am trying to compare to a defined constants in C, and I have simplified my program to the following: #include ... that this cannot be done? 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 - fgets() not waiting for input

I wrote the following code: int N; scanf("%d", &N); int i; for (i = 0; i < N; i++) { char line[ ... time? I feel like it is a threading 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 get terminal window width?

I am working on embedded system using C and linux. User can connect to the device via SSH or a console ... always returns 0 on the device 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 preprocessor - Can CPP preprocessing statement in Fortran be indented?

I am fairly new to use Fortran preprocessing statement and have a question which is probably pretty native. Can ... and thanks 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 - non blocking socket select returns 1 after connect

First of all I would like to say that this is another problem than this one: Similar but not the same My code ... select() is we are connected? 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 global variables in a header file cause link error?

I always get the following error, even if I have put include guard in header file. duplicate symbol _Bittorrent in ... ? 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 - Valgrind Errors on Mac OS X for printf a double

At the moment I am learning C with the awesome learncodethehardway series. I encountered the following: I compile the ... it? THX a lot. 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 convert a K&R function declaration to an ANSI function declaration automatically?

// K&R syntax int foo(a, p) int a; char *p; { return 0; } // ANSI syntax int foo(int a, char *p) ... know such an easy-to-use tool in Linux? 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 - Should I use bit-fields for mapping incoming serial data?

We have data coming in over serial (Bluetooth), which maps to a particular structure. Some parts of the ... the post-processing is simpler. 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 semicolon gives errors but too many of them don't?

Consider this C code: #include <stdio.h>; int main(void) { puts("Hello, world!");; ; ; return 0; ; ... they should be treated as syntax errors. 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 - Confusion with floating point numbers

int main() { float x=3.4e2; printf("%f",x); return 0; } Output: 340.000000 // It's ok. But ... actual output is 312.339996 using GCC compiler. 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 - Confusion about how a getchar() loop works internally

I've included an example program using getchar() below, for reference (not that anyone probably needs it), and feel ... 1; else 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 - printf/fprintf maximum size according to c99

The C99 standard says: The number of characters that can be produced by any single conversion shall be at least 4095 ... its says "at least"? See Question&Answers more detail:os...

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

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433 views

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c - How to calculate the number of days between two given dates? (Leap year obstacle)

Any year evenly divisible by 400 is a leap year (e.g., 2000 was a leap year). Any other year evenly ... that would produce the right answer... 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 - Variadic arguments and x64

How do the va_arg va_start va_list va_end macros work under the hood in x64? The calling convention in i386 passes ... it doesn't clobber them? See Question&Answers more detail:os...

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

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401 views

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c - Behaviour of sizeof with string

?#?include? <stdio.h> #include <string.h> int main() { printf("%d ",sizeof("S65AB")); printf("%d ", ... strings? Using GCC on Debian 7.4 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 the preprocessor directive in one function affect the compilation of another?

Following program compiles successfully and print 1000 without even calling a foo() function from our main() function. How ... ans); 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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417 views

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c - Type of character constant

I am studying physics and in the lecture notes of our programming course it is written that a character constant, in ... a lot for the 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 - How to use a Windows DLL with Java in Mac OS X?

I have seen some Java projects using taucs.dll, TAUCS-a C library of sparse linear solvers, through JNI in ... if anyone has an experience? 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 - Keep only the 10 useful bits in 16-bit words

I have _m256i vectors that contain 10-bit words inside 16-bit integers (so 16*16-bit containing only 16*10 ... bitstream of 10-bit values? See Question&Answers more detail:os...

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

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471 views

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c - implicit int and implicit declaration of functions with gcc compiler

I read in the c99 Standard: -remove implicit function declaration, -remove implicit int. But when I try to compile ... s written "done". 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 - passing pointers to a function

I'm trying to change where the pointers min and max are pointer to, but it seems that the "change" is not sticking ... *min, *max); 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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391 views

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c - Why does 2 dimension array passing to function requires its size?

Inspired this quiestion . Why does - void display(int p[][SIZE]) // allowed and void display(int p[][]) // not allowed ? 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 the ASCII value of a digit character is equal to the value plus '0'?

Why when we want to convert an ASCII value of a digit into an integer, we need to do: value - '0' ? And the ... do: value + '0' Why is 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 - Retrieving total line numbers in a file

can someone show me how to get the total number of lines in a text file in programming language 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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430 views

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c - Write simultaneousely to two streams

Is there a way to to couple two streams (or file descriptors) together so that writing to one stream will also write ... one? (C, Linux) 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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644 views

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c - How does an array of structures with flexible array members behave?

As the title states I was wondering how arrays of C-structs with a flexible array member behaves. Here is an ... /sc22/wg14/www/docs/n1570.pdf See Question&Answers more detail:os...

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

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591 views

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c - Statically linking against LAPACK

I'm attempting to do a release of some software and am currently working through a script for the build process. ... -llapack -o eigen eigen.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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