Correction du laboratoire Gallimard

gallimard.c

/**
 * Gallimard text analyser.
 *
 * See the help below to get information about how this proogram works.
 */
#include <ctype.h>
#include <stdbool.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>

#define BUFFER_SIZE 4096

typedef struct stats {
    // Number of...
    unsigned int words;
    unsigned int chars;
    unsigned int lines;
    unsigned int punctuations;

    char longest_word[64];
} Stats;

void process_string(const char *str, Stats *stats)
{
    struct {
        const char *start;
        size_t length;
    } word = {0};
    bool in_word = false;
    const char *c;
    while (*(c = str++) != '\0') {
        stats->chars++;

        if (isalpha(*c) || *c == '-') {
            if (!in_word) word.start = c;
            word.length++;
            in_word = true;
        } else if (in_word) {
            stats->words++;
            if (word.length > strlen(stats->longest_word)) {
                // One doesn't write trailling `\0` as longest_word
                // was primarly initialized.
                memcpy(stats->longest_word, word.start, word.length);
            }
            word.length = 0;
            in_word = false;
        }

        if (*c == '\n') {
            stats->lines++;
        } else if (ispunct(*c)) {
            stats->punctuations++;
        }
    }
}

void write_stats(Stats stats, FILE *fp)
{
    fprintf(fp, "{\n");
    fprintf(fp, "  \"words\": %d,\n", stats.words);
    fprintf(fp, "  \"lines\": %d,\n", stats.lines);
    fprintf(fp, "  \"chars\": %d,\n", stats.chars);
    fprintf(fp, "  \"ponctuations\": %d,\n", stats.punctuations);
    fprintf(fp, "  \"longest-word\": \"%s\"\n", stats.longest_word);
    fprintf(fp, "}\n");
}

void version(FILE *fp)
{
    fprintf(fp,
            "Version 0.0.1 "
            "Copyright(c) HEIG-VD\n"
            "Yves.Chevallier <yves.chevallier@heig-vd.ch>\n");
}

void help(FILE *fp)
{
    fprintf(fp,
            "usage: ./gallimard [options] [filename]\n\n"
            "This program is similar to wc and displays some statistics \n"
            "about an ASCII file. It reads from [filename] or if missing, \n"
            "directly from STDIN.\n\n"
            "The output format is JSON compliant.\n\n"
            "Options:\n\n"
            "    --version      Displays the program's version\n"
            "    --help         Shows this help dialog\n"
            "    -o<filename>   Write output on <filename>\n\n"
            "Output:\n\n"
            "    - Number of words\n"
            "    - Number of lines\n"
            "    - Number of characters (bytes)\n"
            "    - Longest word in the text file\n");
}

int main(int argc, char *argv[])
{
    char *in_filename = NULL;
    char *out_filename = NULL;

    // Process arguments
    for (int i = 1; i < argc; i++) {
        char *arg = argv[i];

        if (strcmp(arg, "--version") == 0) {
            version(stdout);
            exit(EXIT_SUCCESS);
        } else if (strcmp(arg, "--help") == 0) {
            help(stdout);
            exit(EXIT_SUCCESS);
        } else if (arg[0] == '-' && arg[1] == 'o') {
            arg += 2;
            if (arg[2] == '\0') {
                // Attempt to read filename from the next argument
                if (i++ >= argc) {
                    fprintf(stderr, "Error: cannot read output filename!");
                    return 3;
                }
                out_filename = &argv[i][0];
            } else {
                out_filename = arg;
            }
        } else {
            in_filename = arg;
        }
    }

    // Open input file (from STDIN or from filename)
    FILE *fp = stdin;
    if (in_filename != NULL) {
        if ((fp = fopen(in_filename, "r")) == NULL) {
            fprintf(stderr, "Error: cannot open '%s'!", in_filename);
            return 2;
        }
    }

    // Compute statistics
    Stats stats = {0};
    char buffer[BUFFER_SIZE];
    while (fgets(buffer, BUFFER_SIZE, fp) != NULL) {
        process_string(buffer, &stats);
    }

    // Display results on STDOUT or write to filename
    write_stats(stats, out_filename != NULL ? fopen(out_filename, "w") : stdout);

    return 0;
}