Search Results

Search found 916 results on 37 pages for 'stdio'.

Page 10/37 | < Previous Page | 6 7 8 9 10 11 12 13 14 15 16 17  | Next Page >

  • long integer problem

    - by hopefulLLl
    hello friends,, m a beginner at c language.. m using turbo c ++ compiler 16 bit. nw the max answer obtained by me is aaround 32000.. nw if i want a number larger that that then i use long int.. if i execute the following programme.. #include <stdio.h> void main() { long int x; x=40000; printf("%d", x); } then i get error that constant value is long in function main().. kindly tell me how to get an answer more that 32000 by getting rid of this error! thnx..

    Read the article

  • Why am I not getting the expected results with fread() in C?

    - by mauvehead
    Here is my code: #include <stdio.h> int main(void) { FILE *fp; unsigned int i; char bytes[512]; fp = fopen("myFile","r"); for(i = 0;i <= 512;i++) { fread(&bytes, sizeof(bytes), 1, fp); printf("bytes[%d]: %x\n", i, bytes[i]); } } Here is the expected output $ hexdump myFile 0000000 aa55 aa55 0060 0000 0a17 0000 b1a5 a2ea 0000010 0000 0000 614c 7563 616e 0000 0000 0000 0000020 0000 0000 0a68 0000 1001 421e 0000 0000 0000030 f6a0 487d ffff ffff 0040 0000 002f 0000 But here is what I see from my program bytes[0]: 55 bytes[1]: 8 bytes[2]: ffffffc8 bytes[3]: ffffffdd bytes[4]: 22 bytes[5]: ffffffc8 bytes[6]: ffffff91 bytes[7]: 63 bytes[8]: ffffff82 My obvious guess is that I'm either addressing something incorrectly and receiving the wrong data back or I am printing it incorrectly and viewing it the wrong way.

    Read the article

  • Long Double in C

    - by reubensammut
    I've been reading the C Primer Plus book and got to this example #include <stdio.h> int main(void) { float aboat = 32000.0; double abet = 2.14e9; long double dip = 5.32e-5; printf("%f can be written %e\n", aboat, aboat); printf("%f can be written %e\n", abet, abet); printf("%f can be written %e\n", dip, dip); return 0; } After I ran this on my macbook I was quite shocked at the output: 32000.000000 can be written 3.200000e+04 2140000000.000000 can be written 2.140000e+09 2140000000.000000 can be written 2.140000e+09 So I looked round and found out that the correct format to display long double is to use %Lf. However I still can't understand why I got the double abet value instead of what I got when I ran it on Cygwin, Ubuntu and iDeneb which is roughly -1950228512509697486020297654959439872418023994430148306244153100897726713609 013030397828640261329800797420159101801613476402327600937901161313172717568.0 00000 can be written 2.725000e+02 Any ideas?

    Read the article

  • Why is .NET faster than C++ in this case?

    - by acidzombie24
    -edit- I LOVE SLaks comment. "The amount of misinformation in these answers is staggering." :D Calm down guys. Pretty much all of you were wrong. I DID make optimizations. It turns out whatever optimizations I made wasn't good enough. I ran the code in GCC using gettimeofday (I'll paste code below) and used g++ -O2 file.cpp and got slightly faster results then C#. Maybe MS didn't create the optimizations needed in this specific case but after downloading and installing mingw I was tested and found the speed to be near identical. Justicle Seems to be right. I could have sworn I use clock on my PC and used that to count and found it was slower but problem solved. C++ speed isn't almost twice as slower in the MS compiler. When my friend informed me of this I couldn't believe it. So I took his code and put some timers onto it. Instead of Boo I used C#. I constantly got faster results in C#. Why? The .NET version was nearly half the time no matter what number I used. C++ version: #include <iostream> #include <stdio.h> #include <intrin.h> #include <windows.h> using namespace std; int fib(int n) { if (n < 2) return n; return fib(n - 1) + fib(n - 2); } int main() { __int64 time = 0xFFFFFFFF; while (1) { int n; //cin >> n; n = 41; if (n < 0) break; __int64 start = __rdtsc(); int res = fib(n); __int64 end = __rdtsc(); cout << res << endl; cout << (float)(end-start)/1000000<<endl; break; } return 0; } C# version: using System; using System.Collections.Generic; using System.Linq; using System.Text; using System.Runtime.InteropServices; using System.ComponentModel; using System.Threading; using System.IO; using System.Diagnostics; namespace fibCSTest { class Program { static int fib(int n) { if (n < 2)return n; return fib(n - 1) + fib(n - 2); } static void Main(string[] args) { //var sw = new Stopwatch(); //var timer = new PAB.HiPerfTimer(); var timer = new Stopwatch(); while (true) { int n; //cin >> n; n = 41; if (n < 0) break; timer.Start(); int res = fib(n); timer.Stop(); Console.WriteLine(res); Console.WriteLine(timer.ElapsedMilliseconds); break; } } } } GCC version: #include <iostream> #include <stdio.h> #include <sys/time.h> using namespace std; int fib(int n) { if (n < 2) return n; return fib(n - 1) + fib(n - 2); } int main() { timeval start, end; while (1) { int n; //cin >> n; n = 41; if (n < 0) break; gettimeofday(&start, 0); int res = fib(n); gettimeofday(&end, 0); int sec = end.tv_sec - start.tv_sec; int usec = end.tv_usec - start.tv_usec; cout << res << endl; cout << sec << " " << usec <<endl; break; } return 0; }

    Read the article

  • Why doesn't GCC produce a warning when assigning a signed literal to an unsigned type?

    - by maerics
    Several questions on this website reveal pitfalls when mixing signed and unsigned types and most compilers seem to do a good job about generating warnings of this type. However, GCC doesn't seem to care when assigning a signed constant to an unsigned type! Consider the following program: /* foo.c */ #include <stdio.h> int main(void) { unsigned int x=20, y=-30; if (x > y) { printf("%d > %d\n", x, y); } else { printf("%d <= %d\n", x, y); } return 0; } Compilation with GCC 4.2.1 as below produces no output on the console: gcc -Werror -Wall -Wextra -pedantic foo.c -o foo The resulting executable generates the following output: $ ./foo 20 <= -30 Is there some reason that GCC doesn't generate any warning or error message when assigning the signed value -30 to the unsigned integer variable y?

    Read the article

  • how does fgets internally works?

    - by Registered User
    Well it is a basic question but I seem confused enough. #include<stdio.h> int main() { char a[100]; printf("Enter a string\n"); scanf("%s",a); } Basically the above is what I want to achieve. If I enter a string James Bond then I want that to be stored in array a. But the problem is because of presence of a blank space in between only James word is stored. So how can I solve this one. UPDATE After the replies given below I understand fgets() would be a better choice. I want to know internal working of fgets as why is it able to store the string with space where as scanf is not able to do the same.

    Read the article

  • Problem with the program!

    - by hopefulLLl
    Can you tell me what is the problem with this function. Can you help me to find the sum of digits of a number? #include<stdio.h> #include<math.h> void main() { int a,i=0,j=10,k,n=0,m; scanf("%d",&a); while((a%j!=0)&&i>=0) { m=pow(10,(i+1)); k=a%m; n=(a-(k*m)-n)/(m/10)+n; j=m*10; i++; } n=n+(n/(m/10)); printf("%d",n); } I need to use just the while loop... or the for loop! when i run it it shows"resumable processor fault"..help!

    Read the article

  • why does this code crash?

    - by ashish yadav
    why does this code crash? is using strcat illegal on character pointers? #include <stdio.h> #include <string.h> int main() { char *s1 = "Hello, "; char *s2 = "world!"; char *s3 = strcat(s1, s2); printf("%s",s3); return 0; } please give a proper way with referring to both array and pointers.

    Read the article

  • Why does it NOT give a segmentation violation?

    - by user198729
    The code below is said to give a segmentation violation: #include <stdio.h> #include <string.h> void function(char *str) { char buffer[16]; strcpy(buffer,str); } int main() { char large_string[256]; int i; for( i = 0; i < 255; i++) large_string[i] = 'A'; function(large_string); return 1; } It's compiled and run like this: gcc -Wall -Wextra hw.cpp && a.exe But there is nothing output. NOTE The above code indeed overwrites the ret address and so on if you really understand what's going underneath.

    Read the article

  • How does dereferencing of a function pointer happen?

    - by eSKay
    Why and how does dereferencing a function pointer just "do nothing"? This is what I am talking about: #include<stdio.h> void hello() { printf("hello"); } int main(void) { (*****hello)(); } From a comment over here: function pointers dereference just fine, but the resulting function designator will be immediately converted back to a function pointer And from an answer here: Dereferencing (in way you think) a function's pointer means: accessing a CODE memory as it would be a DATA memory. Function pointer isn't suppose to be dereferenced in that way. Instead, it is called. I would use a name "dereference" side by side with "call". It's OK. Anyway: C is designed in such a way that both function name identifier as well as variable holding function's pointer mean the same: address to CODE memory. And it allows to jump to that memory by using call () syntax either on an identifier or variable. How exactly does dereferencing of a function pointer work?

    Read the article

  • [C] this code, its work fine and return what i want, but its hang before print it ??

    - by Rami Jarrar
    I make this program :: #include<stdio.h> char *raw_input(char *msg); main() { char *s; *s = *raw_input("Message Here Is: "); printf("Return Done.."); printf(s); } char *raw_input(char *msg){ char *d; printf("%s", msg); scanf("%s",&d); return d; } What this do is, it print my message and scan for input from the user, then print it,, but whats the problem in print the input from the user ???

    Read the article

  • function prototype declarations

    - by sandy101
    I am practice the function in c and come across to the program .... #include<stdio.h> int main() { float a=15.5; char ch ='C'; printit(a,ch); return 0; } printit(a,ch) { printf("%f\n%c",a,ch); } I want to know that why the above program compile and not give the error as i understood so for is ... The function in c must be declared with the specific prototype (but this program does not contain the prototype) why the program give the output 'x'for the char variable ? can the function in c are capable of accepting the value without being declared about type in parameters like what has done in the function declaration ?

    Read the article

  • dose not name a type error in c++

    - by user985316
    #include <math.h> #include <stdlib.h> #include <stdio.h> #include <vector> #define IE 40 #define JE 40 #define KE 40 #define ia 7 #define ja 7 #define ka 7 #define NFREQS 3 using namespace std; main() float l,m,n,i,j,k,ic,jc,kc,nsteps,n_pml; float ddx,dt,T,epsz,muz,pi,eaf,npml; int ib,jb,kb; . . . . ic=IE*0.5 ; jc=JE*0.5 ; ....'ic'dose not name a type. ....'jc'dose not name a type.

    Read the article

  • Printf is not printing anything to output? C++ SDL

    - by Qasim
    I am trying to use "printf" in my Visual C++ project however it is not working. Using Lazy Foo's tutorial, I set up SDL in my project, but when I play it, printf doesnt do anything. #include "SDL.h" #include <stdio.h> int main( int argc, char* args[] ) { printf("Testing"); return 0; } The output looks like this: The program '[4664] SDL Testing.exe: Native' has exited with code 0 (0x0). And that's about it. What could be wrong?

    Read the article

  • [C] this code, its work fine and return what i want, but its hangs before print it ??

    - by Rami Jarrar
    I make this program :: #include<stdio.h> char *raw_input(char *msg); main() { char *s; *s = *raw_input("Message Here Is: "); printf("Return Done.."); printf(s); } char *raw_input(char *msg){ char *d; printf("%s", msg); scanf("%s",&d); return d; } What this do is, it print my message and scan for input from the user, then print it,, but whats the problem in print the input from the user ??? Update:: I need the raw_input func. call be like this without any extra *s = *raw_input("Message Here"); I dont want to use this :: raw_input("Message Here Is: ", d); .... Just want to return the string that the user will enter .

    Read the article

  • Elapsed time of running a C program

    - by yCalleecharan
    Hi, I would like to know what lines of C code to add to a program so that it tells me the total time that the program takes to run. I guess there should be counter initialization near the beginning of main and one after the main function ends. Is the right header clock.h? Thanks a lot... Update I have a Win Xp machine. Is it just adding clock() at the beginning and another clock() at the end of the program? Then I can estimate the time difference. Yes, you're right it's time.h. Here's my code: #include <stdio.h> #include <stdlib.h> #include <math.h> #include <share.h> #include <time.h> void f(long double fb[], long double fA, long double fB); int main() { clock_t start, end; start = clock(); const int ARRAY_SIZE = 11; long double* z = (long double*) malloc(sizeof (long double) * ARRAY_SIZE); int i; long double A, B; if (z == NULL) { printf("Out of memory\n"); exit(-1); } A = 0.5; B = 2; for (i = 0; i < ARRAY_SIZE; i++) { z[i] = 0; } z[1] = 5; f(z, A, B); for (i = 0; i < ARRAY_SIZE; i++) printf("z is %.16Le\n", z[i]); free(z); z = NULL; end = clock(); printf("Took %ld ticks\n", end-start); printf("Took %f seconds\n", (double)(end-start)/CLOCKS_PER_SEC); return 0; } void f(long double fb[], long double fA, long double fB) { fb[0] = fb[1]* fA; fb[1] = fb[1] - 1; return; } Some errors with MVS2008: testim.c(16) : error C2143: syntax error : missing ';' before 'const' testim.c(18) :error C2143: syntax error : missing ';' before 'type' testim.c(20) :error C2143: syntax error : missing ';' before 'type' testim.c(21) :error C2143: syntax error : missing ';' before 'type' testim.c(23) :error C2065: 'z' : undeclared identifier testim.c(23) :warning C4047: '==' : 'int' differs in levels of indirection from 'void *' testim.c(28) : error C2065: 'A' : undeclared identifier testim.c(28) : warning C4244: '=' : conversion from 'double' to 'int', possible loss of data and it goes to 28 errors. Note that I don't have any errors/warnings without your clock codes. LATEST NEWS: I unfortunately didn't get a good reply here. But after a search on Google, the code is working. Here it is: #include <stdio.h> #include <stdlib.h> #include <math.h> #include <share.h> #include <time.h> void f(long double fb[], long double fA, long double fB); int main() { clock_t start = clock(); const int ARRAY_SIZE = 11; long double* z = (long double*) malloc(sizeof (long double) * ARRAY_SIZE); int i; long double A, B; if (z == NULL) { printf("Out of memory\n"); exit(-1); } A = 0.5; B = 2; for (i = 0; i < ARRAY_SIZE; i++) { z[i] = 0; } z[1] = 5; f(z, A, B); for (i = 0; i < ARRAY_SIZE; i++) printf("z is %.16Le\n", z[i]); free(z); z = NULL; printf("Took %f seconds\n", ((double)clock()-start)/CLOCKS_PER_SEC); return 0; } void f(long double fb[], long double fA, long double fB) { fb[0] = fb[1]* fA; fb[1] = fb[1] - 1; return; } Cheers

    Read the article

  • C Check Substring of a String C

    - by user69514
    I'm trying to check whether or not the second argument in my program is a substring of the first argument. The problem is that it only work if the substring starts with the same letter of the string. EDIT: It must be done in C, not C++. Sorry #include <stdio.h> #include <string.h> int my_strstr( char const *s, char const *sub ) { char const *ret = sub; while ( ret = strchr( ret, *sub ) ) { if ( strcmp( ++ret, sub+1 ) == 0 ) return 1; } return 0; } int main(int argc, char **argv){ if (argc != 3) { printf ("Usage: check <string one> <string two>\n"); } int result = my_strstr(argv[1], argv[2]); if(result == 1){ printf("%s is a substring of %s\n", argv[2], argv[1]); } else{ printf("%s is not a substring of %s\n", argv[2], argv[1]); } return 0; }

    Read the article

  • Implementing callback functions in C

    - by robertjohn123
    Hi, I am a newbie to C.I am trying to implement callback function using function pointers. I am getting an error :test_callback.c:10: error: expected identifier or ‘(’ before ‘void’ when I try to compile the following program: #include<stdio.h> void (*callback) (void); void callback_proc () { printf ("Inside callback funtion\n"); } void register ((void (*callback) (void))) { printf ("Inside registration \n"); callback (); /* Calling an initial callback with function pointer */ } int main () { callback = callback_proc;/* Assigning function to the function pointer */ register (callback);/* Passing the function pointer */ return 0; } What is this error?Can anyone help?

    Read the article

  • dangling pointer, reason for value change after free()?

    - by Aman Jain
    In the following code segment, after free(x), why does y becomes 0? As per my understanding, the memory in the heap that was being pointed to by x, and is still being pointed by y, hasn't been allocated to someone else, so how can it change to 0? And moreover, I don't think it is free(x) that changed it to 0. Any comments? #include <stdio.h> int main ( int argc, char *argv[] ) { int *y = NULL; int *x = NULL; x = malloc(4); *x = 5; y = x; printf("[%d]\n", *y); //prints 5 free(x); printf("[%d]\n", *y); //why doesn't print 5?, prints 0 instead return 0; }

    Read the article

  • Why does this give a segmentation fault?

    - by nightcracker
    I'm stunned, why does this code give me a segmentation fault? #include <stdio.h> #define LIMIT 1500000 typedef struct { int p; int a; int b; } triplet; int main(int argc, char **argv) { int i; triplet triplets[LIMIT]; for (i = 0; i < 5; i++) { triplets[i].p = 9; // remove this line and everything works fine } printf("%d\n", triplets[15].p); return 0; } EDIT: After changing LIMIT to 150 I no longer get a segmentation fault, it prints random numbers instead.

    Read the article

  • Data loss between conversion

    - by Alex Brooks
    Why is it that I loose data between the conversions below even though both types take up the same amount of space? If the conversion was done bitwise, it should be true that x = z unless data is being stripped during the conversion, right? Is there a way to do the two conversions without losing data (i.e. so that x = z)? main.cpp: #include <stdio.h> #include <stdint.h> int main() { double x = 5.5; uint64_t y = static_cast<uint64_t>(x); double z = static_cast<double>(y) // Desire : z = 5.5; printf("Size of double: %lu\nSize of uint64_t: %lu\n", sizeof(double), sizeof(uint64_t)); printf("%f\n%lu\n%f\n", x, y, z); } Results: Size of double: 8 Size of uint64_t: 8 5.500000 5 5.000000

    Read the article

  • C: Incompatible types?

    - by Airjoe
    #include <stdlib.h> #include <stdio.h> struct foo{ int id; char *bar; char *baz[6]; }; int main(int argc, char **argv){ struct foo f; f.id=1; char *qux[6]; f.bar=argv[0]; f.baz=qux; // Marked line return 1; } This is just some test code so ignore that qux doesn't actually have anything useful in it. I'm getting an error on the marked line, incompatible types when assigning to type ‘char *[6]’ from type ‘char **’ but both of the variables are defined as char *[6] in the code. Any insight?

    Read the article

  • Setting the Cursor Position in a Win32 Console Application

    - by Jim Fell
    How can I set the cursor position in a Win32 Console application? Preferably, I would like to avoid making a handle and using the Windows Console Functions. (I spent all morning running down that dark alley; it creates more problems than it solves.) I seem to recall doing this relatively simply when I was in college using stdio, but I can't find any examples of how to do it now. Any thoughts or suggestions would be greatly appreciated. Thanks.

    Read the article

  • SWIG & C/C++ Python API connected - SEGFAULT

    - by user289637
    Hello, my task is to create dual program. At the beginning I start C program that calls throught C/C++ API of Python some Python method. The called method after that call a function that is created with SWIG. I show you my sample also with backtrace from gdb after I am given Segmentation fault. main.c: #include <Python.h> #include <stdio.h> #include "utils.h" int main(int argc, char** argv) { printf("Calling from C !\n"); increment(); int i; for(i = 0; i < 11; ++i) { Py_Initialize(); PyObject *pname = PyString_FromString("py_function"); PyObject *module = PyImport_Import(pname); PyObject *dict = PyModule_GetDict(module); PyObject *func = PyDict_GetItemString(dict, "ink"); PyObject_CallObject(func, NULL); Py_DECREF(module); Py_DECREF(pname); printf("\tbefore finalize\n"); Py_Finalize(); printf("\tafter finalize\n"); } return 0; } utils.c #include <stdio.h> #include "utils.h" void increment(void) { printf("Incremention counter to: %u\n", ++counter); } py_function.py #!/usr/bin/python2.6 '''py_function.py - Python source designed to demonstrate the use of python embedding''' import utils def ink(): print 'I am gonna increment !' utils.increment() and last think is my Makefile & SWIG configure file Makefile: CC=gcc CFLAGS=-c -g -Wall -std=c99 all: main main: main.o utils.o utils_wrap.o $(CC) main.o utils.o -lpython2.6 -o sample swig -Wall -python -o utils_wrap.c utils.i $(CC) utils.o utils_wrap.o -shared -o _utils.so main.o: main.c $(CC) $(CFLAGS) main.c -I/usr/include/python2.6 -o main.o utils.o: utils.c utils.h $(CC) $(CFLAGS) -fPIC utils.c -o $@ utils_wrap.o: utils_wrap.c $(CC) -c -fPIC utils_wrap.c -I/usr/include/python2.6 -o $@ clean: rm -rf *.o The program is called by ./main and there is output: (gdb) run Starting program: /home/marxin/Programming/python2/sample [Thread debugging using libthread_db enabled] Calling from C ! Incremention counter to: 1 I am gonna increment ! Incremention counter to: 2 before finalize after finalize I am gonna increment ! Incremention counter to: 3 before finalize after finalize I am gonna increment ! Incremention counter to: 4 before finalize after finalize Program received signal SIGSEGV, Segmentation fault. 0xb7ed3e4e in PyObject_Malloc () from /usr/lib/libpython2.6.so.1.0 Backtrace: (gdb) backtrace #0 0xb7ed3e4e in PyObject_Malloc () from /usr/lib/libpython2.6.so.1.0 #1 0xb7ca2b2c in ?? () #2 0xb7f8dd40 in ?? () from /usr/lib/libpython2.6.so.1.0 #3 0xb7eb014c in ?? () from /usr/lib/libpython2.6.so.1.0 #4 0xb7f86ff4 in ?? () from /usr/lib/libpython2.6.so.1.0 #5 0xb7f99820 in ?? () from /usr/lib/libpython2.6.so.1.0 #6 0x00000001 in ?? () #7 0xb7f8dd40 in ?? () from /usr/lib/libpython2.6.so.1.0 #8 0xb7f4f014 in _PyObject_GC_Malloc () from /usr/lib/libpython2.6.so.1.0 #9 0xb7f99820 in ?? () from /usr/lib/libpython2.6.so.1.0 #10 0xb7f4f104 in _PyObject_GC_NewVar () from /usr/lib/libpython2.6.so.1.0 #11 0xb7ee8760 in _PyType_Lookup () from /usr/lib/libpython2.6.so.1.0 #12 0xb7f99820 in ?? () from /usr/lib/libpython2.6.so.1.0 #13 0x00000001 in ?? () #14 0xb7f8dd40 in ?? () from /usr/lib/libpython2.6.so.1.0 #15 0xb7ef13ed in ?? () from /usr/lib/libpython2.6.so.1.0 #16 0xb7f86ff4 in ?? () from /usr/lib/libpython2.6.so.1.0 #17 0x00000001 in ?? () #18 0xbfff0c34 in ?? () #19 0xb7e993c3 in ?? () from /usr/lib/libpython2.6.so.1.0 #20 0x00000001 in ?? () #21 0xbfff0c70 in ?? () #22 0xb7f99da0 in ?? () from /usr/lib/libpython2.6.so.1.0 #23 0xb7f86ff4 in ?? () from /usr/lib/libpython2.6.so.1.0 #24 0xb7f86ff4 in ?? () from /usr/lib/libpython2.6.so.1.0 #25 0x080a6b0c in ?? () #26 0x080a6b0c in ?? () #27 0xb7e99420 in PyObject_CallFunctionObjArgs () from /usr/lib/libpython2.6.so.1.0 #28 0xb7f86ff4 in ?? () from /usr/lib/libpython2.6.so.1.0 #29 0xb7f86ff4 in ?? () from /usr/lib/libpython2.6.so.1.0 #30 0x800e55eb in ?? () #31 0x080a6b0c in ?? () #32 0xb7e9958c in PyObject_IsSubclass () from /usr/lib/libpython2.6.so.1.0 #33 0xb7f8dd40 in ?? () from /usr/lib/libpython2.6.so.1.0 #34 0x080a9020 in ?? () #35 0xb7fb78f0 in PyFPE_counter () from /usr/lib/libpython2.6.so.1.0 #36 0xb7f86ff4 in ?? () from /usr/lib/libpython2.6.so.1.0 #37 0x00000000 in ?? () Thanks for your help and advices, marxin

    Read the article

< Previous Page | 6 7 8 9 10 11 12 13 14 15 16 17  | Next Page >