difference between strncat and memcpy

Question

Please find below code snippet. Is there any chance wherein strncat and memcpy will have different values in pDBVal. If so, Please explain.

memcpy(pDBVal, pHash, 20); 

strncat(pDBVal, cBinSalt, 16);

memcpy(pDBVal+20,cBinSalt,16);

Ideally output in pDBVal will be same. Also please explain the difference in execution of both the functions

They are completely different. It looks like you are using trial and error to solve your problem. What are you trying to achieve? — David Heffernan, Jul 07 '14 at 08:16
Do not use `strXX` functions for binary data. Do not use `memXX` functions for strings. That is the difference. For "explaining the difference in execution", read any [reference](http://en.cppreference.com/w/c/string/byte) [guide](http://en.cppreference.com/w/c/string/byte/memcpy). — Jongware, Jul 07 '14 at 08:26

score 3 · Accepted Answer · answered Jul 07 '14 at 08:15

3

strncat is supposed to be used for string concatenation, so in

strncat(pDBVal, cBinSalt, 16);

If the length of cBinSalt is less than 16, only the content up to '\0' is copied.

answered Jul 07 '14 at 08:15

Yu Hao

1 Answers1