TechPitcher » C++ http://www.techpitcher.com Mon, 20 Dec 2010 10:28:24 +0000 http://wordpress.org/?v=2.9.1 en hourly 1 Implement strtok() function. (It tokenizes the string ) http://www.techpitcher.com/implement-strtok-function-it-tokenizes-the-string.html http://www.techpitcher.com/implement-strtok-function-it-tokenizes-the-string.html#comments Sun, 04 May 2008 18:28:35 +0000 Abhishek http://techpitcher.com/?p=23 Implementation of strtok

char* strtok(char *s, const char *delim) {
static char *old = NULL;
char *token;
if(! s) {
s = old;
if(! s) {
return NULL;
}
}
if(s) {
s += strspn(s, delim);
if(*s == 0) {
old = NULL;
return NULL;
}
}

token = s;
s = strpbrk(s, delim);
if(s == NULL) {
old = NULL;
} else {
*s = 0;
old = s + 1;
}
return token;
}

]]> http://www.techpitcher.com/implement-strtok-function-it-tokenizes-the-string.html/feed 0 Write implementation of memcpy and memmove functions? What is the difference between the two? http://www.techpitcher.com/write-implementation-of-memcpy-and-memmove-functions-what-is-the-difference-between-the-two.html http://www.techpitcher.com/write-implementation-of-memcpy-and-memmove-functions-what-is-the-difference-between-the-two.html#comments Fri, 04 Apr 2008 18:23:47 +0000 Abhishek http://techpitcher.com/?p=22 0) { *d++ = *s++; } } Implementation of memmove void memmove(void* dest, void* src, int n_size) { char* d = (char*) dest; char* s = (char*) src; if(d > s) { while(n_size– > 0) { *d– = *s–; } } else { while(n_size– > 0) { *d++ = [...]]]> Implementation of memcpy

void memcpy(void* dest, void* src, int n_size) {
char* d = (char*) dest;
char* s = (char*) src;
while(n_size– > 0) {
*d++ = *s++;
}
}

Implementation of memmove

void memmove(void* dest, void* src, int n_size) {
char* d = (char*) dest;
char* s = (char*) src;
if(d > s) {
while(n_size– > 0) {
*d– = *s–;
}
} else {
while(n_size– > 0) {
*d++ = *s++;
}
}
}

memmove ensure correct copying when the two buffers overlap.

]]> http://www.techpitcher.com/write-implementation-of-memcpy-and-memmove-functions-what-is-the-difference-between-the-two.html/feed 0 What is a dangling pointer? http://www.techpitcher.com/what-is-a-dangling-pointer.html http://www.techpitcher.com/what-is-a-dangling-pointer.html#comments Tue, 04 Mar 2008 18:21:56 +0000 Amit http://techpitcher.com/?p=21 A dangling pointer is a pointer to memory that is no longer allocated. The pointer still points to the memory which earlier was allocated for the data. The data is deleted and the memory may now be used with some other purpose.

{
char *danglingPointer = NULL;
/* … */
{
char localChar;
danglingPointer = &localChar;
}
/* Memory was allocated to danglingPointer in the block. */
/* As soon as program is out of block dandlingPointer points to Memory, */
/* which is free for other use.*/
}

]]> http://www.techpitcher.com/what-is-a-dangling-pointer.html/feed 0 What is a double pointer? Why is it required? Is it necessary in C++? http://www.techpitcher.com/what-is-a-double-pointer-why-is-it-required-is-it-necessary-in-c.html http://www.techpitcher.com/what-is-a-double-pointer-why-is-it-required-is-it-necessary-in-c.html#comments Mon, 04 Feb 2008 18:20:40 +0000 Abhishek http://techpitcher.com/?p=20 Pointer to a pointer is called double pointer. It is needed when one wants to manipulate the pointer itself like in linked list manipulation etc. In C++ same thing can be accomplished using reference which also avoids the overhead of copying.

]]> http://www.techpitcher.com/what-is-a-double-pointer-why-is-it-required-is-it-necessary-in-c.html/feed 0