Eurecom Dictionnary (DRAFT)

General overview

The objective of this project is to complete the C code of a dictionary management system. This system is built upon two components:

A file, storing word (in alphabetical order, or not),

A C program, performing operations on the dictionary. This program reads arguments from the command line, including commands to be performed on the dictionary (e.g., looking for a word), and returns an answer in the terminal.

System specification

Overview

A dictionary is first stored on disk in a text file. Let's start with this reference file: words.txt. This text file contains a list of English words: one word per line. They are classified in alphabetical order. A program, called words, that you ought to write, takes as input two references:

A reference to a "command file" containing a list of commands, one command per line: these commands are to be executed by words. Valid commands are given later.

A reference to a dictionary file (e.g., to words.txt)

For instance, a typical use of words is:

$ ./words fileOfCommands words.txt

Actually, in the repository we provide, the dictionary file is given in the subdirectory data, words is in bin, and we provide examples of command files in examples, so a valid command should rather be: $ cd bin&&./words ../examples/commands1 ../data/words.txt

Commands

The commands to implement are given in the following table. We assume that a dictionary named D has been provided as the second argument to words. Outputs should not be different because we will check your outputs with our own tests. If you want to put extra information, do use a -debug options that activate extra outputs. A command must return either a number, ok, true, false, or error.

$ ./words -debug fileOfCommands words.txt

Command	Action on D	Output (if no error)
add word1 word2 word3 ...	adds words to D	ok
remove word1 word2 ...	removes words from D	ok
size		Total number of words in D (int)
advancedsize ab		Total number of words starting with "ab" in D (int)
save filename	saves D in "filename" in alphabetical order	ok
search word		prints true if the word was found, false otherwise
advancedsearch w?r?d		prints true is at least one word was found, false otherwise
help		help on commands

For each command that could not be executed because of an error, "error" is output to the terminal. It may be optionnaly followed by a message, e.g. "error: memory allocation problem". Any other error message you may decide to use must be sent to stderr.

Implementation

Valid characters

All valid characters are the ones present in words.txt. This includes:

Uppercase and lowercase letters
Numbers 0-9
& ! ' , -, . /
-

We assume that the alphabetical order is the one of the ascii table.

$ man ascii

You can easily find this valid list of characters by running this bash command on the words.txt file:

$ grep -o . data/words.txt | sort -u

compilation and execution

Your implementation must be compilable and runnable on the Linux PCs in the laboratory rooms. We will evaluate the compilation of your code, and then the execution of your program using the tests we provide with the project. The performance of your implementation is very important as well. Thus, for the provided examples, we will evaluate how much time the execution of your program takes. Using the following command, we can deduce how much time your program takes to execute "commands1"

$ cd bin&&time ./words ../examples/commands1 ../data/words.txt

We have prepared a C environment (Makefile, libraries, include) for the project in the following git: https://gitlab.eurecom.fr/ludovic.apvrille/basicos_project_fall2025_forstudents. Clone it as follows:

$ git clone git@gitlab.eurecom.fr:ludovic.apvrille/basicos_project_fall2025_forstudents.git

Once cloned, have a look at the .md file at the root of this git repository.

Bonus

Implementing a command to merge a referenced dictionary file with the opened dictionary.

Automatically compressing/uncompressing dictionary files

Supporting "*" in the advancedsearch command: "*" matches zero or more characters.

For both search command, the number of found words (int) must be followed by a space and then the list of found words (in laphabetical order), each word being separated from the previous one with a space.

Deadlines, deliverables and organization

Program the specified system, and provide the sources files in C, Makefile and one report in markdown format, by Dec. 11th, 2025, 18h00 CET. Advices on how to write a report are given here. Everything should be available in the gitlab of your project. No commit after this date will be considered. If your code does not compile, don't expect to have a grave over 5.

All members of the group must work on the general definition of the dictionary handling (loading in a data structure), and the implementation of the core functions (command analysis). Then, the implementation of commands must be split between the members of the group, as follows:

Members #1 (leader): data structure management and size

Members #2: remove and advancedsize

Members #3: add and save

Members #4: search and advancedsearch

Grading

10 points are given to the whole group, 10 points are given to each student.

5 points for the report. The report covers the work of the whole group, but must emphasize on the work done by each group member.

5 points for the global approach: global algorithm, common code, regular progression on the project.

10 individual points for personal implementation. This grade is individual. If your implementation in C is not ready by the deadline, provide the corresponding algorithm in pseudo code: you can get up five points with a pseudo-code.

How to proceed?

Making groups

Form 17 groups of 4 students and one group of 3 students. Once your group has been established, I would like the designated group leader to send me an email providing the full names and email addresses of all the group members. In the subject line of your email, please include the phrase "[BasicOS] New group". Upon receiving your email, I will confirm your group's formation, assign you a group number.

Setup a gitlab projet (use gitlab.eurecom.fr for this) called EXACTLY basicos2025-teamXX (With XX your group number, for group 1: basicos2025-team01) and send me the link to your gitlab: I will follow your progression that way. Do allow me to clone your gitlab project, as well as Sophie Coudert and Yahya Frioui.

How to work?

First sessions. Clearly define the general structure of your project. Two documents we have prepared should help you for this: the first one on how to structure a C program and the second one on complementary information on the project specification

First and second sessions: program together the main framework: handling of arguments, handling of main commands, handling of errors.

Third session: individually program the commands you are meant to implement. Make individual tests.

Fourth session: integrate together all commands, and check that all the tests you provide run: a part of your grade is based on this. Improve program performance. Provide at least 5 more tests with more that 10 commands each.

Your git must be ready (=STRICT DEADLINE) the 11th of December, 18h00, Paris time.

And do not forget to regularly commit&push on the git. Working in a regular way is part of the final grade.