Programming

The risk of strcpy is this:

Code:

char buf[8]; // Only room for 8 characters
char very_important_variable_touch_and_the_world_explodes=42;

// More than 8 characters, where does the rest go?
strcpy(buf, "HEY GUYS ALJ AF MY FACE IS A ROTTORN BANANA");

So instead, you can do this:

Code:

char buf[8]; 
char very_important_variable_touch_and_the_world_explodes=42;

strncpy(buf, "HEY GUYS ALJ AF MY FACE IS A ROTTORN BANANA", 8);

Which sets the contents of buf to { 'H','E','Y',' ','G','U','Y','S' } and doesn't destroy the world. But because it ran out of room, it couldn't store the null terminator. Meaning buf[] is not guaranteed to contain a proper string after you do strncpy, so trying to use it as a string could cause undefined results and possibly blow up the world. So to be really safe, you do:

Code:

char buf[8]; 
char very_important_variable_touch_and_the_world_explodes=42;

strncpy(buf, "HEY GUYS ALJ AF MY FACE IS A ROTTORN BANANA", 8);

buf[8-1]='\0';

Which sets buf to { 'H','E','Y',' ','G','U','Y','\0' }, which guarantees the buffer is null-terminated whether strncpy ran out of room or not, and does it all without destroying the world.