memcpy

Your mission

Implement gm_memcpy, your own memcpy, which copies exactly n bytes from a source buffer to a destination buffer and returns the destination pointer.

See it in action

gm_memcpy(dst, "git push", 9)

Expected result

git push

Your checklist

For your own tracking. Tests grade your code.

Copy n raw bytes from src to dst, one byte at a time, then return dst.
This is a byte copy, not a string copy: keep going for the full count even after a \0 appears. A NUL is just another byte here, never a stopping point.
When n is 0, copy nothing and leave dst untouched.
Read src and write dst through 'unsigned char *' so every byte is copied verbatim, whatever its value. The two regions are assumed not to overlap.

More examples

gm_memcpy(dst, "rebase --hard", 4); dst[4] = '\0';

Expected result

reba

Constraints

Expected files

memcpy.c

Allowed functions

None. Write every helper yourself.

Allowed headers

<stddef.h>defines size_t

libc

Standard C library

Implements the contract of a function from the standard C library.

memcpy

Bytes and raw memory

Your mission

Implement gm_memcpy, your own memcpy, which copies exactly n bytes from a source buffer to a destination buffer and returns the destination pointer.

See it in action

gm_memcpy(dst, "git push", 9)

Expected result

git push

Your checklist

For your own tracking. Tests grade your code.

Copy n raw bytes from src to dst, one byte at a time, then return dst.
This is a byte copy, not a string copy: keep going for the full count even after a \0 appears. A NUL is just another byte here, never a stopping point.
When n is 0, copy nothing and leave dst untouched.
Read src and write dst through 'unsigned char *' so every byte is copied verbatim, whatever its value. The two regions are assumed not to overlap.

More examples

gm_memcpy(dst, "rebase --hard", 4); dst[4] = '\0';

Expected result

reba

Constraints

Expected files

memcpy.c

Allowed functions

None. Write every helper yourself.

Allowed headers

<stddef.h>defines size_t

libc

Standard C library

Implements the contract of a function from the standard C library.

Tests

Run the tests to grade your code

Build your code, then check each test here. Open a result to inspect its output.

Build

01Copy a full string including its NULWaiting

02Copy only the first 4 bytesWaiting

03Copy 0 bytes leaves dst untouchedWaiting

04Byte copy does not stop at an embedded NULWaiting

05Copies content past the first NULWaiting

06Copy a single byteWaiting

07Returns the destination pointerWaiting

memcpy

Your mission

Implement gm_memcpy, your own memcpy, which copies exactly n bytes from a source buffer to a destination buffer and returns the destination pointer.

See it in action

gm_memcpy(dst, "git push", 9)

Expected result

git push

Your checklist

For your own tracking. Tests grade your code.

Copy n raw bytes from src to dst, one byte at a time, then return dst.
This is a byte copy, not a string copy: keep going for the full count even after a \0 appears. A NUL is just another byte here, never a stopping point.
When n is 0, copy nothing and leave dst untouched.
Read src and write dst through 'unsigned char *' so every byte is copied verbatim, whatever its value. The two regions are assumed not to overlap.

More examples

gm_memcpy(dst, "rebase --hard", 4); dst[4] = '\0';

Expected result

reba

Constraints

Expected files

memcpy.c

Allowed functions

None. Write every helper yourself.

Allowed headers

<stddef.h>defines size_t

libc

Standard C library

Implements the contract of a function from the standard C library.

memcpy

Bytes and raw memory

Your mission

Implement gm_memcpy, your own memcpy, which copies exactly n bytes from a source buffer to a destination buffer and returns the destination pointer.

See it in action

gm_memcpy(dst, "git push", 9)

Expected result

git push

Your checklist

For your own tracking. Tests grade your code.

Copy n raw bytes from src to dst, one byte at a time, then return dst.
This is a byte copy, not a string copy: keep going for the full count even after a \0 appears. A NUL is just another byte here, never a stopping point.
When n is 0, copy nothing and leave dst untouched.
Read src and write dst through 'unsigned char *' so every byte is copied verbatim, whatever its value. The two regions are assumed not to overlap.

More examples

gm_memcpy(dst, "rebase --hard", 4); dst[4] = '\0';

Expected result

reba

Constraints

Expected files

memcpy.c

Allowed functions

None. Write every helper yourself.

Allowed headers

<stddef.h>defines size_t

libc

Standard C library

Implements the contract of a function from the standard C library.

Tests

Run the tests to grade your code

Build your code, then check each test here. Open a result to inspect its output.

Build

01Copy a full string including its NULWaiting

02Copy only the first 4 bytesWaiting

03Copy 0 bytes leaves dst untouchedWaiting

04Byte copy does not stop at an embedded NULWaiting

05Copies content past the first NULWaiting

06Copy a single byteWaiting

07Returns the destination pointerWaiting