1   Instructions

You must implement the following functions, whose behavior must match the documentation for the standard function of the same name (without my_):

const char *my_strchr(const char *s, int c);
unsigned my_strlcpy(char *dst, const char *src, unsigned n);
unsigned my_strlcat(char *dst, const char *src, unsigned n);
int my_strncmp(const char *s1, const char *s2, unsigned n);
void *my_memcpy(void *dst, const void *src, unsigned n);
void *my_memset(void *dst, int c, unsigned n);

You can optionally also implement the following for a higher grade (see Grading below):

const char *my_strrchr(const char *s, int c);
const char *my_strpbrk(const char *s1, const char *s2);
const char *my_strstr(const char *s1, const char *s2);
void *my_memmove(void *dst, const void *src, unsigned n);

Constraints:

• each function must be implemented in a .c file of its own, named after the function it contains. The function prototypes must be declared in a .h file, in accordance with the C coding standard. The submitted archive may (but needs not) include a test program.
• you must not include any standard/system header in your code; nor use any function from the standard C library.

2   Grading

• 1 point per function correctly implemented in the mandatory list.
• +0.5 if all of the above, and a Makefile places the functions in libminic.a.
• +0.5 per optional function correctly implemented after all of the above.
• +0.5 if the submitted archive includes a README file alongside the source files, containing a valid explanation of why this assignment uses “const char *” for my_strchr/my_strrchr whereas the C library uses “char *” for strchr/strrchr.
• +1 point for “cleverness” in either my_strstr, my_memcpy or my_memmove, provided with an explanation and empirical proof of the improvement compared to a naive implementation.

3   Copyright and licensing

Copyright © 2014, Raphael ‘kena’ Poss. Permission is granted to distribute, reuse and modify this document and other documents for the Systems Programming course by the same author according to the terms of the Creative Commons Attribution-ShareAlike 4.0 International License. To view a copy of this license, visit http://creativecommons.org/licenses/by-sa/4.0/.