"you're trying to initialize a struct, from a pointer."
I thought with the typedef...
This would mean that the following statement would be assigning a ptr to a ptr...
Because a region_t is a ptr type...or in other words, an array of section_t* ptrs. Hence my confusion, I thought in C an array and a ptr were essentially the same things, so this would work.
Anyway I got it to work by changing the assignment to the following...
I realised that "ctn.regions[nth]" is basically an array without the subscript, which means it's a ptr. And what it points to is a ptr to a "section_t"... voila a ptr to a ptr.
And I can access the section_t* by using the subscript, i.e...
Hi everybody,
i am newbie to unix and confused with file pointers and file descripters.
could anyone help me to clear my doubts ..
when we call unix system calls to create a file then we are dealing wih file descripters
i think file descripters are also normals file as stored inhard disks... (1 Reply)
All ..
I am having a pointer array . And trying to store the addess into that pointer array . please see below the problem i faced
code:
int cnt1;
char *t_array;
char *f_array;
for(cnt1=0; cnt1<1000; cnt1++)
{
t_array =... (1 Reply)
If one wants to get a start address of a array or a string or a block of memory via a function, there are at least two methods to achieve it:
(1) one is to pass a pointer-to-pointer parameter, like:
int my_malloc(int size, char **pmem)
{
*pmem=(char *)malloc(size);
if(*pmem==NULL)... (11 Replies)
if i create an array of pointers to a structure "struct node" as:
struct node *r;
and create "n" number of "linked lists" and assign it to the various struct pointers r using some function with a return type as structure pointer as:
r=multiplty(.......) /*some parameters*/
is... (2 Replies)
Hello,
The purpose of the program is to print a sub string from the prompt inputs. I do not understand why char pointer does not work but char array will for line 40 and Line 41.
./a.out thisisatest 0 8
substring = "thisisat"And my code is:
#include <stdio.h>
#include <stdlib.h>
#include... (29 Replies)
Here are two programs that pass a pointer to a variable but behave differently. Shouldnt the i in second program be 0 after the function call?
#include<stdio.h>
void changeI(int *i)
{
*i = 10;
}
int main(void)
{
int i=5;
printf("%d before\n", i);
changeI(&i);
printf("%d... (1 Reply)
Hi Friends,
I have a host(Suse Linux 10.4) which has 2 luns presented from 2 different arrays HP eva and xp. we are planning to migrate hp eva to 3par. When i look for physical volume i see /dev/dm-4, /dev/dm-5, /dev/dm-7and when i look for multipath -ll i see dm-8,dm-9,dm-7. So i can't confirm... (6 Replies)
I am struggling with the pointer to 2D-array (cf: 2D array of pointers). Can anybody help me elaborate how the pointer x moves in the memory to access the individual of y, especially the high lighted lines?
I have talked to one of the curators of the forum, but I am still not quite clear.
Here... (1 Reply)
Discussion started by: yifangt
1 Replies
LEARN ABOUT BSD
fread
FREAD(3S)FREAD(3S)NAME
fread, fwrite - buffered binary input/output
SYNOPSIS
#include <stdio.h>
fread(ptr, sizeof(*ptr), nitems, stream)
FILE *stream;
fwrite(ptr, sizeof(*ptr), nitems, stream)
FILE *stream;
DESCRIPTION
Fread reads, into a block beginning at ptr, nitems of data of the type of *ptr from the named input stream. It returns the number of items
actually read.
If stream is stdin and the standard output is line buffered, then any partial output line will be flushed before any call to read(2) to
satisfy the fread.
Fwrite appends at most nitems of data of the type of *ptr beginning at ptr to the named output stream. It returns the number of items
actually written.
SEE ALSO read(2), write(2), fopen(3S), getc(3S), putc(3S), gets(3S), puts(3S), printf(3S), scanf(3S)DIAGNOSTICS
Fread and fwrite return 0 upon end of file or error.
4th Berkeley Distribution May 15, 1985 FREAD(3S)