What is diff b/w malloc,calloc,realloc

[Ramasubramanian XR (AS/EAB)]

What is diff b/w malloc,calloc,realloc
could any one explain

 

[Duck Dodgers]

malloc returns uninitialized memory, calloc initializes the memory to
all bits zero, and realloc is way more flexible than it should be.
realloc can act like malloc or free, or it can resize memory returned
by malloc, calloc, or a previous realloc call, possibly allocating a
new block and invalidating any pointers into the memory.

 

[not]

What is diff b/w malloc,calloc,realloc
could any one explain

Pointer = malloc(Size)
Allocates a new block of memory.

Pointer = realloc(OldPointer, Size)
Resizes an existing block of memory

Pointer = calloc(NumBlocks, BlockSize) ...
Clears and allocates the given number of blocks of a given size. (most
useful for arrays)

 

[Richard Bos]

Pointer = calloc(NumBlocks, BlockSize) ...
Clears and allocates the given number of blocks of a given size. (most
useful for arrays)

Be careful, though: "clears" means "fills with 0-valued bytes", not
necessarily "fills with zero values". In particular, 0x00000000 need not
be the representation of a zero-valued floating point number or of a
null pointer.

Richard

 

[Default User]

What is diff b/w malloc,calloc,realloc
could any one explain

What book are you using that doesn't cover such fundamental memory
management functions?




Brian

 

[Emmanuel Delahaye]

Ramasubramanian XR (AS/EAB) wrote on 23/03/05 :

What is diff b/w malloc,calloc,realloc
could any one explain

It's all explained in any decent C book or help file.

google : "man malloc" "man realloc" "man calloc"

--
Emmanuel
The C-FAQ: http://www.eskimo.com/~scs/C-faq/faq.html
The C-library: http://www.dinkumware.com/refxc.html

I once asked an expert COBOL programmer, how to
declare local variables in COBOL, the reply was:
"what is a local variable?"

 

[Stan Milam]

What is diff b/w malloc,calloc,realloc
could any one explain

Why don't you read the manual or man pages like the rest of us did?