C++ Etymology

string.h

strcpy, strdup, strncpy

char * strcpy ( char * Destination, const char * Source );

char * strdup ( const char * Source );

char * strncpy ( char * Destination, const char * Source, size_t count );

Count

The maximum number of characters to be copied. 

Destination

A pointer to the receiving field. 

Source

A pointer to the string to be copied. 

strcpy

A pointer to the receiving field. 

strdup

A pointer to the receiving field. 

strncpy

A pointer to the receiving field. 

• strcpy does not verify the size of the receiving field.  If the receiving field is shorter than the source string, the copy will overrun the receiving field, possibly causing errors. 
• strdup allocates new memory for the receiving field. 
• strncpy copies Count characters.  If the length of the Source string is greater than Count, no NULL ('\n') character is appended to the receiving field.  If the length of the Source string is less than Count, the rest of the receiving field is filled with NULL ('\n') characters.