Voir la source de INTERNATIONAL:Eval:C

[[category:EPITA:TP:20142015]]
== Introduction ==

The purpose of this micro-project is to evaluate basic knowledge in C. You
must respect the presentation and organization rules (directory and file
names, format of the output … )

=== Requirements ===

All the required files must be in the a single directory named after your
login of the form: <tt>login-eval20150127</tt>. The content of the directory
must follow this layout:

* login-eval20150127
** Makefile
** main.c
** readfile.c
** readfile.h
** sort.c
** sort.h

'''The directory must contains theses files and only these files.'''

All the code must compile correctly (see next section) without warnings and
must obey to the C99 standard.

In order to provided your files, you'll build a compressed archive using
<tt>tar</tt> and the bzip2 compression algorithm (option <tt>j</tt> in
<tt>tar</tt>.) The archive name must have the form:
<tt>login-eval20150127.tar.bz2</tt>.

=== Evaluation ===

The main evaluation will be automatic, your archive and your code must
strictly obey to the form described in this document, otherwise it won't be
evaluated.

In order to evaluated, your program must successfully compile and run without failure.

== Building your Code: <tt>Makefile</tt> ==

Your code will be build using the command <tt>make</tt> that take its form
from the file <tt>Makefile</tt>. This file must provide the following rules:

* <tt>all</tt>: build the main program called <tt>main</tt>
* <tt>main</tt>: same as <tt>all</tt>
* <tt>clean</tt>: remove all files produced by the compilation process (including <tt>main</tt>)

You must use the compiler named <tt>gcc</tt> with the following options (for C
files) : <tt>-Wall -Wextra -std=c99 -O2</tt>.

Here is a template <tt>Makefile</tt> to help you start:

<source lang="make">
# Makefile

CC=gcc
CFLAGS= -Wall -Wextra -std=c99 -O2
LDFLAGS=
LDLIBS=

all: main

# FIX The following rules

main:

clean:

# END
</source>

== The main goal ==

This program is pretty simple, it reads a file containing integer (in ASCII)
stores them in an array, sorts them and print them on the standard output.

The following sections describe each sub-parts, files by files.

=== Reading the files ===

* '''file: ''' <tt>readfile.c</tt>

You must provide a function that take a file name and a pointer to an array (thus
a pointer on a pointer), reads the file, allocates correctly an array to store
the integers from the file and returns the number of integers stored in the
array.

The file has the simplest possible format: one integer (in ASCII) per line.

<tt>readfile.c</tt> must provide at least the following function:

<source lang="C">
size_t read_file(char *name, int **tab);
</source>

Your code should follow this schema:

* open the file <tt>name</tt>, quit the program with an error message if opening fails
* allocate an array
* read the file line by line, and for each line:
** get the integer
** store the integer in the array, extending it if needed
* store the array address in <tt>*tab</tt>
* returns the number of integers stored in the array

Of course, the file <tt>readfile.h</tt> will exposed <tt>read_file</tt>.

=== Sorting the array ===

* '''file: ''' <tt>sort.c</tt>

This file must provide a sort function for an array of integers. The function
has the following prototype:

<source lang="C">
void sort_int(int tab[], size_t len);
</source>

* <tt>tab</tt> is the array
* <tt>len</tt> is the len of the array (number of elements)

The array must be sorted in increasing order ''w.r.t.'' the natural integer
order.

'''This part must not use any library functions, including the function
<tt>qsort</tt>.''' A validation procedure will be run on the code to detect
any usage of these functions.

You can implement any sorting algorithm, '''but''' your code will be test
against big set of data (100MB or more) and must run in reasonable time.

Of course, the file <tt>sort.h</tt> will exposed <tt>sort_int</tt>.

=== Main program ===

* '''file: ''' <tt>main.c</tt>

This the main program, it will:

* Check that at least one argument has been provided
** if no arguments are provided, the program quit with an error message
* Call <tt>read_file</tt> with the first argument
* Call <tt>sort_int</tt> with the array built with <tt>read_file</tt>
* Display the sorted array on standard output, one integer per line
* Free the memory allocated to the array
* Exit

Some general remarks about the program:

* When leaving with an error, the status of the program must be greater than 0 and less than 127.
* All error messages must be printed on the standard error output stream (<tt>stderr</tt>)
* The only permitted output is the final result (content of the sorted array.)
* Any memory allocation must be freed before leaving