so it's essentially only if you want to reserve a segment of memory(to assure that it's always there)
Um, no. Statically allocated memory is always there, guaranteed (otherwise the program won't even start). Via malloc you ask the OS for some memory. If you get it, it's yours until you return it. If you don't your program has to cope with that (either complain to the user and/or try again later). It's the same in C#, if the VM doesn't have any memory left for objects you can't create them.
Quote:
Originally Posted by james2432
and to access via pointer later(not that I like using pointers)?
Good luck then, because in C/C++ there are very, very few things you can do without pointers. Arrays, for example:
For some reason, I'm having a bit of a brain fart here and cannot think of a simple solution to this problem...
We have a samba server installed on one of our Darwin boxes. Someone is doing massive amounts of work through a samba share, and in turn in pegging samba and the box. I can see how... (1 Reply)
I currently access a remote Unix server which has an external modem connected to one of it's serial ports (/dev/cua/b). At times, this server undergoes a hard reset and for some reason this disallows us from making use of the modem any longer. A hard reset of the modem always seems to fix the... (0 Replies)
Hi,
I got a solarsi 10 box with 9 zones and the cpu shares as following
ID NAME SHARES
0 global 1
1 FMW1 100
2 FMW2 100
3 OID1 100
4 OID2 100
5 OVD1 100
6 OID0 100
7 FMW5 100
8... (2 Replies)
Hello,
I am trying to free memory allocation after EOF from keyboard is detected (ctrl+D) in a C program. I've written a small program to replicate my problem:
int main(int argc, char *argv) {
char *line;
line = (char*)malloc(sizeof(char)*(512));
line = fgets(line, 512,... (1 Reply)
Hello,
I am trying to free memory allocation after EOF from keyboard is detected (ctrl+D) in a C program. I've written a small program to replicate my problem:
int main(int argc, char *argv) {
char *line;
line = (char*)malloc(sizeof(char)*(512));
line = fgets(line, 512,... (10 Replies)
Here is a list of resources for Unix and GNU/Linux bootloaders:
GRUB Legacy: The original GRand Unified Bootloader. Now known as GRUB Legacy.
GRUB: The latest and greatest. More commonly known as GRUB2.
BRUG: Brand-new Universal loadeR from GRUB. Based on GRUB. Adds features like new object... (0 Replies)
Hi guys,
I wrote a basic inotifywait shell script on my CentOS 5.6 x86_64 test server that syncs any deleted files in a directory.
/usr/bin/script
#!/bin/sh
inotifywait -m -e delete /home/user/test | while read file; do
# log event here
done
The script alone works fine. However, the... (4 Replies)
:)Hi all,
Please advice me is it safer to use the following command to free up (truncate) space in HDD.
1) > /usr/adm/messages
2) > /usr/adm/sulog
3) > /usr/adm/ctlog
4) > /tmp
5) > /usr/adm/sa
6) > /var/spool
Thanks in advance
Rukshan (1 Reply)
Discussion started by: rukshan4u2c
1 Replies
LEARN ABOUT HPUX
xtrealloc
XtRealloc() XtRealloc()
Name
XtRealloc - change the size of an allocated block of storage.
Synopsis
char *XtRealloc(ptr, num);
char *ptr;
Cardinal num;
Inputs
ptr Specifies a pointer to memory allocated with XtMalloc(), XtCalloc(), or XtRealloc(), or NULL.
num Specifies the new number of bytes of memory desired in the block.
Returns
A pointer to allocated memory.
Description
XtRealloc() changes the size of the block of allocated memory pointed to by ptr to be at least num bytes large. In order to make this size
change, it may have to allocate a new block of memory and copy the contents of the old block (or as much as will fit) into the new block.
If it allocates a new block of memory, it frees the old block. In either case, it returns a pointer to a block of memory which is of the
requested size. If there is insufficient memory to allocate the new block, XtRealloc() terminates by calling XtErrorMsg().
If ptr is NULL, XtRealloc() simply calls XtMalloc() to allocate a block of memory of the requested size.
Usage
Note that XtRealloc() may move the contents of your allocated memory to a new location; the return value may or may not be the same as ptr.
Not all memory can be safely reallocated. If there are multiple pointers to a block of memory scattered through out an application (such
as pointers to a widget record), then reallocating that memory is not safe, because all pointers to it cannot be updated. Other memory
(such as the array of children maintained privately by the Composite widget class) can be safely updated because there should be only one
pointer to it in the application (in this case the pointer is the composite.children field of the widget). These cautions are no different
than those required with the standard realloc() function.
In most cases, you will have to cast the return value of XtRealloc() to an appropriate pointer type.
Note that because XtRealloc() behaves like XtMalloc() when passed a NULL pointer, (something that realloc() does not do), you don't have to
write special case code to allocate the first chunk of memory with XtMalloc() and subsequent chunks with XtRealloc(); you can simply use
XtRealloc() everywhere.
Memory allocated with XtRealloc() must be deallocated with XtFree(). The function XtRealloc() is implemented by the Toolkit independently
of the particular environment, so programs ported to a system not supporting malloc will still work.
See AlsoXtCalloc(1), XtFree(1), XtMalloc(1), XtNew(1), XtNewString(1).
Xt - Memory Allocation XtRealloc()