10 More Discussions You Might Find Interesting
1. Programming
Hi everyone,
i made this program. is a simple one for practising malloc, realloc and structs.
I have a struct named shop as global variable in which i take the size of the matrix from the keyboard and after i malloc it.
I insert the values with the fullarray() and after i print the matrix with... (7 Replies)
Discussion started by: giampoul
7 Replies
2. UNIX for Dummies Questions & Answers
#include <malloc.h>
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
int*
allocat_array(void)
{
int *array;
int tmp;
int n_values = 0 ;
array = malloc(sizeof(int));
if(array == NULL)
return NULL;
while(scanf("%d",&tmp) != EOF)
{
... (1 Reply)
Discussion started by: vincent__tse
1 Replies
3. Programming
Not sure in which forum to post this. I'm trying here, in Programming.
I'm working on a PC with Intel Duo processor & 2GB of ram. OS is Ubuntu 10.04.
I'm having problems with a C++ program that makes extensive use of realloc(). It happens that as soon as the overall memory allocated(OS +... (14 Replies)
Discussion started by: mamboknave
14 Replies
4. Programming
b = realloc(a, 1000);
if realloc succeeds and b!=a (not in-place replacement), does realloc automatically free a or I should free both a and b afterwards?
thank you! (5 Replies)
Discussion started by: bashuser2
5 Replies
5. Programming
Hi all
I'm trying to use someone else's software, which has a realloc that fails in it. This is probably due to memory limitations, as it only happens when I use this software on huge datasets.
First question : how to diagnose if it's a soft or hard limitation? I mean, if it's due to my... (10 Replies)
Discussion started by: jossojjos
10 Replies
6. Programming
Hi,
I am seeing varying results about, when realloc() fails in reallocation.
Which one is correct out of the below?
a) realloc() maintains the original pointer (i.e) the original pointer is left unaltered/untouched but relloc() returns the NULL value.
b) original buffer pointer is lost... (3 Replies)
Discussion started by: royalibrahim
3 Replies
7. Programming
Why when using realloc, john is reversed 3 times but not the other 2 names ? But if I use malloc, then the 3 names are reversed correctly ? (but then there is a memory leak)
How can I reverse all 3 names without a memory leak ?
char *BUFFER = NULL;
char *STRREVERSE(const char *STRING)
{... (5 Replies)
Discussion started by: cyler
5 Replies
8. Programming
N00B here. This function would be easier using a char pointer along with free. But I wish to learn how to use char static pointers (they do not require free, right ?).
How do I erase the content of a static pointer ? Terminating the string works but the static pointer's content is not being... (4 Replies)
Discussion started by: limmer
4 Replies
9. Programming
hi,
I'm using gcc version 3.4.6 on a Red Hat system... (not sure how to determine version of glibc)
when i run the following, i get:
glibc detected *** realloc(): invalid next size: 0x0804a170
I'm not sure what is wrong. The error happens on the second iteration of
the while loop.... (3 Replies)
Discussion started by: Andrewkl
3 Replies
10. Programming
Hello,
my program works properly but valgrind tells me I am not freeing allocated memory. I think the problem is in realloc.
I am pretty sure I do something wrong with realloc, because I changed it a bit and valgrind noticed less errors (that the program wasn't working properly with less errors... (3 Replies)
Discussion started by: samciz
3 Replies
MALLOC(2) System Calls Manual MALLOC(2)
NAME
malloc, free, realloc, calloc - memory allocator
SYNOPSIS
#include <u.h>
#include <libc.h>
void* malloc(long size)
void free(void *ptr)
void* realloc(void *ptr, long size)
void* calloc(long nelem, long elsize)
DESCRIPTION
Malloc and free provide a simple memory allocation package. Malloc returns a pointer to a new block of at least size bytes. The block is
suitably aligned for storage of any type of object. No two active pointers from malloc will have the same value.
The argument to free is a pointer to a block previously allocated by malloc; this space is made available for further allocation. It is
legal to free a null pointer; the effect is a no-op.
Realloc changes the size of the block pointed to by ptr to size bytes and returns a pointer to the (possibly moved) block. The contents
will be unchanged up to the lesser of the new and old sizes. The call realloc(0, size) means the same as
Calloc allocates space for an array of nelem elements of size elsize. The space is initialized to zeros. Free frees such a block.
Alef
Except for calloc, these routines are available from Alef; they use the same arena as alloc. Malloc and realloc execute a check when they
fail, rather than return nil. Memory returned by malloc is cleared. Realloc does not guarantee new memory is cleared unless ptr is nil.
SOURCE
/sys/src/libc/port/malloc.c
SEE ALSO
brk(2)
DIAGNOSTICS
Malloc, realloc and calloc return 0 if there is no available memory. Errstr is likely to be set.
BUGS
The different specification of calloc is bizarre.
User errors can corrupt the storage arena. The most common gaffes are (1) freeing an already freed block, (2) storing beyond the bounds of
an allocated block, and (3) freeing data that was not obtained from the allocator. When malloc and free detect such corruption, they
abort.
MALLOC(2)