Sponsored Content
Full Discussion: Passing pointers to struct
Homework and Emergencies Homework & Coursework Questions Passing pointers to struct Post 302486469 by m.d.ludwig on Saturday 8th of January 2011 07:59:14 PM
Old 01-08-2011
The size of a void is 1, so only 1 byte is getting written. You need to provide the size of the structure, either:
Code:
int bwrite(unsigned int bloque, void *buf, size_t siz){
    lseek(mifd, bloque*tbloque, SEEK_SET);
    return write(mifd, buf, siz);
}

or
Code:
 int bwrite(unsigned int bloque, struct superbloque  *buf){
     lseek(mifd, bloque*tbloque, SEEK_SET);
     return write(mifd, buf, sizeof(*buf));
 }


Last edited by m.d.ludwig; 01-08-2011 at 08:59 PM.. Reason: superfluous word
 

10 More Discussions You Might Find Interesting

1. Programming

Need a simple example of passing FILE pointers

Dear friends, can anybody pls tell me how to pass FILE pointer in c. I am so confused .. :confused: suppose I ve two function 1. file_open() 2. read_line() I want to call these function from main() function and in file_open() function it will open that file and in read_line()... (5 Replies)
Discussion started by: user_prady
5 Replies

2. Programming

Pointer to a struct (with pointers) *** glibc detected *** double free

I am using a structure defined as follows struct gene_square { double *x; double *y; };I have class, with a member function which is a pointer of this type: gene_square* m_Genes;I am allocating memory in the constructors like this: m_Genes = new gene_square; for (ii=0;... (1 Reply)
Discussion started by: jatoo
1 Replies

3. UNIX for Advanced & Expert Users

Passing socket struct between kernel threads - module programming

I write kernel module with kernel threads using linux/kthread.h on 2.6.* kernel I tried to passing data between two kernel threads with data argument of kthread_run( fun, data , NAME ); but this is not work I dont know why. I tried many possibility and nothing works. So I thought that... (0 Replies)
Discussion started by: marcintom
0 Replies

4. Homework & Coursework Questions

C++ struct pointers & functions

Hi All, My latest assignment (practice not coursework!) is to write prototype interactive exam/test console application. I've used structs to store the question information (not sure if this was the best way to do it?) and I have the following code that outputs each question and it's possible... (0 Replies)
Discussion started by: pondlife
0 Replies

5. UNIX for Dummies Questions & Answers

Passing struct through unix pipe -solved

EDIT: Nevermind, called a friend who is good at this stuff and he figured it out :D Hi all, So I'm trying to teach myself to write programs for unix in c. I am currently creating a program, and I need to pass a struct through a pipe, but I can't figure out how. The struct I want to pass... (0 Replies)
Discussion started by: twnsfn34
0 Replies

6. UNIX for Dummies Questions & Answers

How to access a struct within a struct?

Can someone tell me how to do this? Just a thought that entered my mind when learning about structs. First thought was: struct one { struct two; } struct two { three; } one->two->three would this be how you would access "three"? (1 Reply)
Discussion started by: unbelievable21
1 Replies

7. Programming

Passing an instance of struct to functions in other src files

I am trying to work out the best syntax for a relatively simple operation. The goal is to declare an instance of a struct and pass it around to be populated and have the data manipulated. There is an extra wrinkle in that the functions are in different src files. The main is simple, #include... (5 Replies)
Discussion started by: LMHmedchem
5 Replies

8. Programming

Using pointers to struct members as args to functions

In a well-known book on the C language, there is an example of an efficient method for using a struct member as an argument to a function. (I'm a C noob, but I believe the correct terminology might be: use call-by-reference instead of call-by-value.) The function is printf. Anyway, here's a... (5 Replies)
Discussion started by: uiop44
5 Replies

9. Programming

Passing Pointers by reference in C++ Problem

Hello All, I am having this issue...where I am actually having hard time understanding the problem: The code is as follows: #include<iostream.h> void fxn(char*** var) { int i =4; *var = (char**)malloc(i*sizeof(char*)); for(int j =0; j<4; j++) { *var = "name"; cout<<*var;... (6 Replies)
Discussion started by: mind@work
6 Replies

10. Programming

Storing C++-struct in file - problem when adding new item in struct

Hi, I have received an application that stores some properties in a file. The existing struct looks like this: struct TData { UINT uSizeIncludingStrings; // copy of Telnet data struct UINT uSize; // basic properties: TCHAR szHost; //defined in Sshconfig UINT iPortNr; TCHAR... (2 Replies)
Discussion started by: Powerponken
2 Replies
list(3) 						    InterNetNews Documentation							   list(3)

NAME
list - list routines SYNOPSIS
#include <inn/list.h> struct node { struct node *succ; struct node *pred; }; struct list { struct node *head; struct node *tail; struct node *tailpred; }; void list_new(struct list *list); struct node *list_addhead(struct list *list, struct node *node); struct node *list_addtail(struct list *list, struct node *node); struct node *list_head(struct list *list); struct node *list_tail(struct list *list); struct node *list_succ(struct node *node); struct node *list_pred(struct node *node); struct node *list_remhead(struct list *list); struct node *list_remtail(struct list *list); struct node *list_remove(struct node *node); struct node *list_insert(struct list *list, struct node *node, struct node *pred); bool list_isempty(struct list *list); DESCRIPTION
list_new initialises the list header list so as to create an empty list. list_addhead adds node to the head of list, returning the node just added. list_addtail adds node to the tail of list, returning the node just added. list_head returns a pointer to the the node at the head of list or NULL if the list is empty. list_tail returns a pointer to the the node at the tail of list or NULL if the list is empty. list_succ returns the next (successor) node on the list after node or NULL if node was the final node. list_pred returns the previous (predecessor) node on the list before node or NULL if node was the first node. list_remhead removes the first node from list and returns it to the caller. If the list is empty NULL is returned. list_remtail removes the last node from list and returns it to the caller. If the list is empty NULL is returned. list_remove removes node from the list it is on and returns it to the caller. list_insert inserts node onto list after the node pred. If pred is NULL then node is added to the head of list. HISTORY
Written by Alex Kiernan <alex.kiernan@thus.net> for InterNetNews 2.4.0. $Id: list.pod 9074 2010-05-31 19:01:32Z iulius $ INN 2.5.3 2011-06-10 list(3)
All times are GMT -4. The time now is 09:30 AM.
Unix & Linux Forums Content Copyright 1993-2022. All Rights Reserved.
Privacy Policy