edward.p.rutherford79's articles:

Items(18) /2 Next >> Last >|

Pointer Arithmetic & UB 143 30 (12/10/2012 5:14:18 PM) comp.lang.c Hello Would the following code invoke an undefined behavior? char a[10]; size_t i=20,j=15; *(a+i-j)=42; It potentially constructs the invalid pointer a+i as an intermediate value. But overall the a... Edward

Function factories 42 36 (8/21/2012 8:36:31 PM) comp.lang.c Hello I want to make a factory that produces other functions according to a parameter. The following code does not compile: typedef int *(foo)(int); foo adder_factory(int x) { int f(int a) ... Edward

scanf() #2 33 38 (8/6/2012 8:58:11 PM) comp.lang.c Hello If scanf() fails for a matching error, what can we say about the location of the file pointer for subsequent reads from stdin? Could it have read on through an indeterminate amount of stdin, or wil... Edward

const vs typedef 8 21 (4/18/2012 8:26:58 PM) comp.lang.c I've got an opaque type encapsulated with a typedef, ie typedef struct my_obj *my_obj_handle; What I want is to define a function type that takes one of these handles in such a way that the function cant modi... Edward

varargs function, is this legal? #2 4 24 (4/12/2012 8:54:27 PM) comp.lang.c Hello: void myfunc(char * format, int param1, ...) { va_list argp; va_start(argp, format); #if CONDITION some code involving param1 #endif some code that uses format and argp va_end(argp);... Edward

Call Backs 10 20 (2/15/2012 7:33:39 PM) comp.lang.c I've read plenty of discussion about callback functions as used in C (ie in qsort). I'm comfortable with this: really it is a function pointer. What I'm not sure about is how (or if) a callback differs to ev... Edward

Function pointer vs conditional branch 37 43 (1/4/2012 10:20:18 PM) comp.lang.c Hello As a general rule-of-thumb: Are function pointers more efficient than if statements, if the same path will be taken throughout the course of the program? E.g. If I was going to repeatedly render an im... Edward

Comparing fp types for equality 14 27 (12/20/2011 9:09:14 AM) comp.lang.c This code for the comparison of fp types is taken from the C FAQ. Any problems using it in a macro? /* compare 2 doubles for equality */ #define DBL_ISEQUAL(a,b) (((fabs)(((a)-(b)))<=(DBL_EPSILON)*(fabs)((a)))... Edward

Repeated types in union 21 31 (12/10/2011 10:06:08 PM) comp.lang.c Hello : Is the following code an undefined behavior? union { int a; int b; } u; u.a = 3; printf("%d\n", u.b); Cheers Edward ... Edward

Struct casting 16 33 (12/5/2011 9:52:13 PM) comp.lang.c This was pulled up at a code review. Code was similar to this: struct foo { int bar; int baz; } f; int * i = (int *) f; The only way this could go wrong is if the struct contains padding before its firs... Edward

edward.p.rutherford79's replies:

Items(18) /2 Next >> Last >|

Segmentation Fault #31 30 29 (5/14/2012 4:45:17 PM) comp.lang.c I am sure that I am missing something but I cannot get the following code to work. It doesn't even make it to my test printf statement before I get a segmentation fault. Does anyone have any ideas why I can't... once1 (21)

Generic programming in C. 65 37 (5/18/2012 9:14:35 AM) comp.lang.c When I presented an example of the interface here (thread CCL vs STL, a comparison), many posters complained about the syntax: int main(void) { List *L; int data; L = iList.Create(sizeof(int))... jacob31 (874)

Signed mod unsigned 29 30 (6/6/2012 1:55:07 PM) comp.lang.c Hi group, today I ran into something I honestly did not expect. Consider this snippet: #include int main() { int i1, i2; unsigned int u2; i1 = -1; i2 = 30; u2 = 30; printf("%d\n", i1... dfnsonfsduifb (1169)

Learning C as an existing programmer 92 34 (6/24/2012 9:52:37 PM) comp.lang.c Hi I need to learn C for numerical analysis as part of my Masters research. I already have quite a lot of experience with BASIC (my progression was GW BASIC -> QBASIC -> Visual BASIC -> VB.net) so I wan... nospam21 (11323)

scanf() #2 33 38 (8/6/2012 8:58:11 PM) comp.lang.c Hello If scanf() fails for a matching error, what can we say about the location of the file pointer for subsequent reads from stdin? Could it have read on through an indeterminate amount of stdin, or wil... edward.p.rutherford79 (45)

Array passed as function parameters 24 33 (8/16/2012 1:25:57 PM) comp.lang.c Could anyone please explain the differences between the following array passing? Thanks! 1) int get_data(char d[100]) {...} 2) int get_data(char *d) {...} /WT ... ytlim1 (236)

Calloc arguments order 22 29 (8/19/2012 8:55:10 PM) comp.lang.c Hello I would like to understand something about the Calloc function. " void *calloc(size_t nmemb, size_t size); The calloc() function allocates memory for an array of nmemb elements of size byte... raj121190 (27)

Function factories 42 36 (8/21/2012 8:36:31 PM) comp.lang.c Hello I want to make a factory that produces other functions according to a parameter. The following code does not compile: typedef int *(foo)(int); foo adder_factory(int x) { int f(int a) ... edward.p.rutherford79 (45)

2D arrays, pointers, and pointer arithmetic: question 33 38 (8/24/2012 3:28:33 PM) comp.lang.c I'm reading "A Book on C", 4th edition. The author gives the following example when discussing two dimensional arrays: a[3][5], so let a[][] be of type int. col 1 col 2 col 3 ... gdotone (12)

typedef, 2D arrays, design: question 11 23 (9/1/2012 4:25:30 AM) comp.lang.c I am reading "A Book on C" forth edition. In chapter 6, the author discusses "The Use of typedef". The following is t= he examples given in the book: #define N 3 typedef double scalar; typedef scal... gdotone (12)