please reply for this queries

prem_may10's Avatar, Join Date: Sep 2006
Go4Expert Member
hi
1. what is the difference between strcpy and memcpy
2. what is memory leak?
3. what is the difference between general operating system and real time operating system.


Thanks
yasodhar premchand
shabbir's Avatar, Join Date: Jul 2004
Go4Expert Founder
Quote:
Originally Posted by prem_may10
1. what is the difference between strcpy and memcpy
strcpy

strcpy allows null-terminated memory blocks to be copied to different locations. Since, in C, strings are not first-class datatypes, and are implemented as blocks of ASCII bytes in memory, strcpy will effectively copy strings given two pointers to blocks of allocated memory.

memcpy

memcpy() works on arbitrary data of a given fixed length

use memcpy() when you want to copy an exact amount of data (possibly containing embedded null chars) from one location to another, and strcpy() when you want to copy a variable-length null-terminated C string from one location to another...

Quote:
Originally Posted by prem_may10
2. what is memory leak?
Memory leaks are often thought of as failures to release unused memory by a computer program. Strictly speaking, it is just unneccesary memory consumption. As an example Making malloc calls without the corresponding calls to free.

Quote:
Originally Posted by prem_may10
3. what is the difference between general operating system and real time operating system.
OS which performs the task in the real time environment. As an example say you need to embedded applications (programmable thermostats, household appliance controllers, mobile telephones), which cannot take more than a specified time to complete an operation but your normal OS can.
prem_may10's Avatar, Join Date: Sep 2006
Go4Expert Member
hi
still i am not getting the diffrence between strcpy and memcpy. can u explain with examples.


Thanks
yasodhar premchand
shabbir's Avatar, Join Date: Jul 2004
Go4Expert Founder
strcpy is used for copying strings (terminated by a null '\0') but memcpy can be used to copy some data of finite length to the desired memory location.

memcpy(bufDest,bufSrc,100); // Will copy 100 bytes whatever be the content be

strcpy(bufDest,bufSrc); // Will copy all the bytes till it finds the first null terminating character
gunshot08's Avatar, Join Date: Jun 2008
Light Poster
[QUOTE=prem_may10][COLOR=Blue][B]hi
1. what is the difference between strcpy and memcpy

strcpy is a function to copy a charactor array in given memory into another location and leaving the original string in its adress whilst memcopy copies copies all the contents of a given memory