Login or Register to Ask a Question and Join Our Community

Sponsored Content
Full Discussion: Pointer to pointers
Top Forums Programming Pointer to pointers Post 302572419 by DreamWarrior on Thursday 10th of November 2011 02:00:55 AM
Old 11-10-2011
The real problem is that when you say "*str = "hello there"" what you're telling the compiler is to set the value of the memory location pointed to by str to the address of the string "hello there" which resides inside the program's data segment. Because "hello there" is a static string in the program, it must exist in the data segment. Since it's not a heap address, it can not be reallocated via realloc, so it fails when you call realloc.
 

10 More Discussions You Might Find Interesting

1. Programming

Regarding Function and Pointers.

HI, Here is some thing that is puzzling me from a long time. Can some body explain me this with example. The question is :- What is the difference between function pointer and pointer to a function. Where do we actually use the function pointers and pointer to functions. Thanks in... (0 Replies)
Discussion started by: S.Vishwanath
0 Replies

2. Shell Programming and Scripting

functiom pointers

Hi all i wonder about function pointers as i never used them in my C code . could any tell me why and where exactly function pointers come into picture . thanq (1 Reply)
Discussion started by: Raom
1 Replies

3. Programming

pointers

is this a valid c declaration int (*ptr(int *b)); plz explain... (4 Replies)
Discussion started by: areef4u
4 Replies

4. Programming

pointers

Hi I mash with pointers in C. I solve this problem about 5 hours and I don't know how I should continue. void InsertFirst (tList *L, int val) { tElemPtr new; if((new = malloc(sizeof(tElemPtr))) == NULL) Error(); new->data = val; new->ptr = L->frst; L->frst = new;... (2 Replies)
Discussion started by: Milla
2 Replies

5. 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

6. Programming

pass a pointer-to-pointer, or return a pointer?

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)
Discussion started by: aaronwong
11 Replies

7. UNIX for Advanced & Expert Users

shared pointers

I am new to shared pointer conceot in C++ and hence require some clarification: For example: class A { public: virtual ~A() { } int x; }; typedef boost::shared_ptr<A>... (1 Reply)
Discussion started by: uunniixx
1 Replies

8. Programming

Need help with the Pointers in C

I have a special character called ô. When it is declared as a character variable its showing it can be printed. But when it is declared as a character pointer variable its showing it cannot be printed. I am just wondering why its happening like this.. c1 = '@'; c2 = 'ô'; char *fp; fp="XXô"; if... (1 Reply)
Discussion started by: sivakumar.rj
1 Replies

9. Programming

Problem With Pointers

Hi guys. What is the difference between these: 1. int *a; 2. int (*a); (2 Replies)
Discussion started by: majid.merkava
2 Replies

10. Programming

Pointers and array

Hello, I read from a book exercise for a challenge. How to print out each letter of char array a by two different pointers pa and ppa in the example? I have tried my code for letter "r" by testing without full understanding as only the first one worked. #include<stdio.h> int main() { char... (17 Replies)
Discussion started by: yifangt
17 Replies

LEARN ABOUT REDHAT

xmscrollvisible

XmScrollVisible(library call)											     XmScrollVisible(library call)

NAME

       XmScrollVisible -- A ScrolledWindow function that makes an invisible
	descendant of a ScrolledWindow work area visible

SYNOPSIS

       #include <Xm/ScrolledW.h>
       void XmScrollVisible(
       Widget scrollw_widget,
       Widget widget,
       Dimension left_right_margin,
       Dimension top_bottom_margin);

DESCRIPTION

       XmScrollVisible makes an obscured or partially obscured widget or gadget descendant of a ScrolledWindow work area visible. The function re-
       positions the work area and sets the specified margins between the widget and the nearest viewport boundary. The widget's location relative
       to  the	viewport determines whether one or both of the margins must be adjusted. This function requires that the XmNscrollingPolicy of the
       ScrolledWindow widget be set to XmAUTOMATIC.

       scrollw_widget
		 Specifies the ID of the ScrolledWindow widget whose work area window contains an obscured descendant.

       widget	 Specifies the ID of the widget to be made visible.

       left_right_margin
		 Specifies the margin to establish between the left or right edge of the widget and the associated edge  of  the  viewport.   This
		 margin is established only if the widget must be moved horizontally to make it visible.

       top_bottom_margin
		 Specifies  the  margin  to  establish between the top or bottom edge of the widget and the associated edge of the viewport.  This
		 margin is established only if the widget must be moved vertically to make it visible.

       For a complete definition of ScrolledWindow and its associated resources, see XmScrolledWindow(3)

RELATED

       XmScrolledWindow(3).

														     XmScrollVisible(library call)
All times are GMT -4. The time now is 09:53 AM.
Unix & Linux Forums Content Copyright 1993-2022. All Rights Reserved.
Privacy Policy