memset

Bytes and raw memory16

Objective

Implement a function that fills the first n bytes of a memory area with a single byte value, then returns the area's address.

Steps

Walk the memory area s byte by byte and write the same byte into each of the first n positions.
The byte to write comes from c: convert it to unsigned char before storing, so only the low 8 bits are used.
Write exactly n bytes, no more, no less. When n is 0, touch nothing at all.
Return the original pointer s (the address you were given), not a cursor that walked to the end.

examples

$ memset(buf, 'A', 5) // then buf[5]='\0'; print buf

AAAAA

$ memset("commit", '0', 3) // first 3 bytes only

000mit

Constraints

Expected files

memset.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

01Fill 5 bytes, print as string

02Fill only the first 3 bytes

03Zero length leaves the buffer untouched

04c is truncated to one byte (0x141 -> 'A')

05Fill with NUL bytes

06Returns the original pointer

memset

Objective

Implement a function that fills the first n bytes of a memory area with a single byte value, then returns the area's address.

Steps

Walk the memory area s byte by byte and write the same byte into each of the first n positions.
The byte to write comes from c: convert it to unsigned char before storing, so only the low 8 bits are used.
Write exactly n bytes, no more, no less. When n is 0, touch nothing at all.
Return the original pointer s (the address you were given), not a cursor that walked to the end.

examples

$ memset(buf, 'A', 5) // then buf[5]='\0'; print buf

AAAAA

$ memset("commit", '0', 3) // first 3 bytes only

000mit

Constraints

Expected files

memset.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.

memset

Bytes and raw memory16

Objective

Implement a function that fills the first n bytes of a memory area with a single byte value, then returns the area's address.

Steps

Walk the memory area s byte by byte and write the same byte into each of the first n positions.
The byte to write comes from c: convert it to unsigned char before storing, so only the low 8 bits are used.
Write exactly n bytes, no more, no less. When n is 0, touch nothing at all.
Return the original pointer s (the address you were given), not a cursor that walked to the end.

examples

$ memset(buf, 'A', 5) // then buf[5]='\0'; print buf

AAAAA

$ memset("commit", '0', 3) // first 3 bytes only

000mit

Constraints

Expected files

memset.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

01Fill 5 bytes, print as string

02Fill only the first 3 bytes

03Zero length leaves the buffer untouched

04c is truncated to one byte (0x141 -> 'A')

05Fill with NUL bytes

06Returns the original pointer