Objective

Implement a function that copies at most n bytes from src into dst, padding the rest of dst with \0 when src is shorter than n, and writing no terminator at all when src is n bytes or longer.

Steps

• Copy bytes from src into dst until you have written n bytes or you hit the \0 in src, whichever comes first.
• If src was shorter than n, keep going: fill every remaining byte up to n with \0. The whole window of n bytes always gets written.
• Here is the famous footgun: if src is n bytes or longer, you copy exactly n bytes and stop. You do NOT add a terminating \0. The result is not a C string, so printing it with %s would run off the end.
• When n is 0, write nothing at all and leave dst untouched.
• Return dst (the original pointer you were given).
• In the examples below, each byte is printed as itself, every \0 is shown as ., and bytes the function never touched keep the sentinel # they were pre-filled with.

Objective

Implement a function that copies at most n bytes from src into dst, padding the rest of dst with \0 when src is shorter than n, and writing no terminator at all when src is n bytes or longer.

Steps

• Copy bytes from src into dst until you have written n bytes or you hit the \0 in src, whichever comes first.
• If src was shorter than n, keep going: fill every remaining byte up to n with \0. The whole window of n bytes always gets written.
• Here is the famous footgun: if src is n bytes or longer, you copy exactly n bytes and stop. You do NOT add a terminating \0. The result is not a C string, so printing it with %s would run off the end.
• When n is 0, write nothing at all and leave dst untouched.
• Return dst (the original pointer you were given).
• In the examples below, each byte is printed as itself, every \0 is shown as ., and bytes the function never touched keep the sentinel # they were pre-filled with.