Your mission

Write copy_capped, which copies src into dst, a buffer of cap bytes, never writes past the end of that buffer, and returns the length of src.

See it in action

copy_capped(dst, "git", 16)

[git] ret=3 guard=intact

copy_capped(dst, "rebase", 4)

[reb] ret=6 guard=intact

copy_capped(dst, "zsh", 0)

ret=3 guard=intact

Your checklist

• cap is the total size of dst in bytes, terminator included. src is a NUL-terminated string that you only read.
• After the call, dst holds the first cap - 1 bytes of src (all of src when it is shorter) followed by '\0'. No byte at index cap or beyond is written.
• When cap is 0, write nothing at all, not even a terminator.
• Return the length of src, whatever cap is. A return value of cap or more tells the caller the copy was cut short.
• Tests print dst between brackets, the return value, and guard=intact when the bytes just past cap still hold what they held before the call. When cap is 0 there is no string to print.

Your mission

Write copy_capped, which copies src into dst, a buffer of cap bytes, never writes past the end of that buffer, and returns the length of src.

See it in action

copy_capped(dst, "git", 16)

[git] ret=3 guard=intact

copy_capped(dst, "rebase", 4)

[reb] ret=6 guard=intact

copy_capped(dst, "zsh", 0)

ret=3 guard=intact

Your checklist

• cap is the total size of dst in bytes, terminator included. src is a NUL-terminated string that you only read.
• After the call, dst holds the first cap - 1 bytes of src (all of src when it is shorter) followed by '\0'. No byte at index cap or beyond is written.
• When cap is 0, write nothing at all, not even a terminator.
• Return the length of src, whatever cap is. A return value of cap or more tells the caller the copy was cut short.
• Tests print dst between brackets, the return value, and guard=intact when the bytes just past cap still hold what they held before the call. When cap is 0 there is no string to print.