This code was written in response to a weekly code challenge for my local Linux Users Group. It is meant to be an example of coding techniques for people who are not professional programmers. I hoped to demonstrate that a coding assignment is often far more than just writing code; a testing framework to demonstrate correctness and testing use cases, as well as detailed documentation for the end user as well as any future maintainers are critical and integral components of the expected deliverables.
For the most part, these string functions are familiar to even new practitioners of the C language, and are easy to implement. Since there are reference implementations of all these functions readily available on most platforms, writing the test harness is also trivial, so this material should not be intimidating to most students.
The following subset of string functions were implemented. Please see html/index.html for details.
size_t strlen(const char *s);char *strdup(const char *s);char *strtok(char *s, const char *delim);char *strtok_r(char *s, const char *delim, char **ptrptr);char *strchr(const char *s, int c);char *strstr(const char *haystack, const char *needle);int strcmp(const char *s1, const char *s2);int strncmp(const char *s1, const char *s2, size_t n);int strcasecmp(const char *s1, const char *s2);int strncasecmp(const char *s1, const char *s2, size_t n);char *strcat(char *dest, const char *src);char *strncat(char *dest, const char *src, size_t n);char *strcpy(char *dest, const char *src);char *strncpy(char *dest, const char *src, size_t n);
Rules:
- no looking at source to libc, X, kernel, or any other reimplimented these functions
- You may use other headers as needed as long as they themselves don't circularly depend on <string.h>
- Entries must be portable.
This sample implementation of string functions is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; either version 2, or (at your option) any later version.
This sample implementation of string functions is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details.
You should have received a copy of the GNU General Public License along with This sample implementation of string functions; see the file COPYING. If not, write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.