On 31 August 2011 13:42, Avinash Sonawane wrote: > Respected Sir, > I am using gcc version 4.5.2 (Ubuntu/Linaro 4.5.2-8ubuntu4) > > I have one doubt regarding malloc () in gcc. That's not a doubt, it's a question, and it's not a question about gcc so is not really appropriate on this mailing list. > When I tried to execute the program given below, it got executed. > > But since 256 = 1 0000 0000 (9 bits) , How malloc can store it at 'p' > since I have allocate only 1 byte of memory (8 bits of memory) ? The program is invalid, it is your responsibility to use malloc correctly to avoid errors like this. When you call malloc(1) it doesn't create a new piece of memory of 1 byte, isolated from the rest of your computer's memory. It simply returns you a memory address, which points to a block of at least 1 byte. When you write 4 bytes to that address you are overwriting 3 by7tes which you did not get from malloc. That could corrupt your heap memory, or have other nasty effects, possibly eventually causing your program to crash, or worse.
