08-05-2002
1 .I found the answer .
2 .First , I write another programe .
#include <stdio.h>
#include <string.h>
int main(void)
{
char *p;
p = (char *) malloc(100);
strcpy(p, "asdfasdf");
return 0;
}
It works correctly .
3 . Why ? The point is that :
p is a local varible , when we call do_it(p) , the OS pass a copy of p to child function .Though we malloc memory to p in child function ,the p variable in main function is not changed .
10 More Discussions You Might Find Interesting
1. Programming
hello sir
since by mentioning a integer pointer and storing the integers
by incrementing the pointer value
then what is the purpose of malloc?
u can decalre it as
in t *p;
several integers can be stored by incrementing the value of p,
hence what is the diffrence between this... (2 Replies)
Discussion started by: rajashekaran
2 Replies
2. Programming
Hello
This is a simple program i carried out in my machine
i dont know how it is working
#include<alloc.h>
#include<stdio.h>
mian()
{
int *p,j;
p= (int*)malloc(1);
for(j=1;j<=580;j++)
{
*p=j;
++p;
}
p=p-580;
for(j=1;j<=580;j++)
{
printf("%d",*p);
} (7 Replies)
Discussion started by: rajashekaran
7 Replies
3. Programming
Hi All!
Does some one know I am under UNIX system can not allocate more then 1 Mb memory? It broke program down.
Any information would be greatly appreciated.
Thanks. (2 Replies)
Discussion started by: prodigal
2 Replies
4. Programming
Hi!
I hope this is the correct forum to post the question even if I'm a newbie...
I am a C-newbie (and really on the edge to be a C-addict ;) ) and have a question.
When should I use malloc?
To state it differently, when should I NOT use malloc?
For instance, if I have an array of... (5 Replies)
Discussion started by: Tonje
5 Replies
5. Programming
Some one please explain me what is Dynamic memory allocation and the use of malloc() function.How do we allocate memory dynamically and also the other way? (3 Replies)
Discussion started by: rash123
3 Replies
6. Programming
Hey Guys
I am trying to implement the malloc function for my OS class and I am having a little trouble with it. I would be really grateful if I could get some hints on this problem.
So I am using a doubly-linked list as my data structure and I have to allocate memory for it (duh...). The... (1 Reply)
Discussion started by: Gambit_b
1 Replies
7. UNIX for Dummies Questions & Answers
Do kmalloc and malloc allocate from same heap ? (3 Replies)
Discussion started by: dragonpoint
3 Replies
8. Programming
Which one is faster among malloc and new?
My understanding is that since new also has to call constructors after allocating memory it must be slower than malloc.
Am I correct? (1 Reply)
Discussion started by: rupeshkp728
1 Replies
9. UNIX for Dummies Questions & Answers
Good day! I'm a newbie in C. I'm trying to get an unlimited input from the user using malloc then printing the inputs after the user presses enter. My code works, but there's a warning that I don't know how to fix. Please help me. Thank you.
Here's my code:
#include <stdio.h>
#include... (6 Replies)
Discussion started by: eracav
6 Replies
10. Programming
Hello,
I am trying to read a text file into linked list, but always got the first and last records wrong.
1) The problem looks related to the initialization of the node temp with malloc(), but could not figure it out. No error/warning at compiling, though.
2) The output file is empty,... (10 Replies)
Discussion started by: yifangt
10 Replies
LEARN ABOUT DEBIAN
explain_malloc_or_die
explain_malloc_or_die(3) Library Functions Manual explain_malloc_or_die(3)
NAME
explain_malloc_or_die - Allocate and free dynamic memory and report errors
SYNOPSIS
#include <libexplain/malloc.h>
void *explain_malloc_or_die(size_t size);
DESCRIPTION
The explain_malloc_or_die function is used to call the malloc(3) system call. On failure an explanation will be printed to stderr,
obtained from explain_malloc(3), and then the process terminates by calling exit(EXIT_FAILURE).
This function is intended to be used in a fashion similar to the following example:
void *result = explain_malloc_or_die(size);
size The size, exactly as to be passed to the malloc(3) system call.
Returns:
This function only returns on success. On failure, prints an explanation and exits.
SEE ALSO
malloc(3)
Allocate and free dynamic memory
explain_malloc(3)
explain malloc(3) errors
exit(2) terminate the calling process
COPYRIGHT
libexplain version 0.52
Copyright (C) 2009 Peter Miller
explain_malloc_or_die(3)