Implementation of 452 strcpy, strcat, StrCmp, strstr, strchr

1、strcpy function

char* strcpy(char* des, const char* src);

effect ：

• It's from src Address start , String containing string terminator Copied to the With dest In the starting address space ;
• src and dest The memory area cannot be overlapped . This requires that dest There must be enough room for src String .

Ideas ：

• Yes src Copy strings one by one , When you meet NULL when ,dest Stop copying .

char* my_strcpy（