SC5 - TD6 - Exo4 - Q7

copy.c

#include "copy.h"

static int count_lines(FILE *in) {
    int cur = -1, prev, lines = 0;
    do {
        prev = cur;
        cur = fgetc(in);
        if (cur == '\n')
            ++lines;
    } while (cur != EOF);
    if (prev != '\n' && lines)
        ++lines;
    return lines;
}

static int digits(int i) {
    int d = 0;
    do {
        i /= 10;
        ++d;
    } while (i != 0);
    return d;
}

void copy(FILE *in, FILE *out) {
    int lines = count_lines(in);
    rewind(in);

    char *line = NULL;
    size_t len = 0;
    ssize_t read;
    int space_len = digits(lines);

    int i = 0;
    long open = -1, close = -1;

    while ((read = getline(&line, &len, in)) != -1) {
        if (strstr(line, "||:") == line) {
            open = ftell(in) - read;
        } else if (strstr(line, ":||") == line + read - 4 && close != ftell(in)) {
            close = ftell(in);
            fseek(in, open, SEEK_SET);
        }
        fprintf(out, "%*d %s", space_len, ++i, line);
    }

    free(line);
}

copy.h

#ifndef COPY_H
#define COPY_H

#include <stdlib.h>
#include <stdio.h>
#include <string.h>

void copy(FILE *in, FILE *out);

#endif

exo3.c

#include <stdlib.h>
#include <stdio.h>
#include "copy.h"

int main(int argc, char **argv) {
    if (argc <=1) {
        fputs("Not enough arguments.\nUsage: copy <source> <dest>\n", stderr);
        exit(EXIT_FAILURE);
    }

    FILE *in = fopen(argv[1], "r");
    if (!in) {
        perror("Error opening input file");
        exit(EXIT_FAILURE);
    }
    FILE *out;
    if (argc == 2) {
        out = stdout;
    } else {
        out = fopen(argv[2], "w");
        if (!out) {
            perror("Error opening output file");
            exit(EXIT_FAILURE);
        }
    }

    copy(in, out);
    fclose(in);
    fclose(out);
}

Makefile

# $@	Le nom de la cible
# $<	Le nom de la première dépendance
# $^	La liste des dépendances
# $?	La liste des dépendances plus récentes que la cible
# $*	Le nom du fichier sans suffixe

CC=gcc
CFLAGS=-Wall
LDFLAGS=
EXEC=copy

all: $(EXEC)

copy: copy.o exo3.o
	$(CC) $(CFLAGS) -o $@ $^ $(LDFLAGS)

%.o: %.c
	$(CC) $(CFLAGS) -o $@ -c $< $(LDFLAGS)

clean:
	rm -rf *.o *.ghc

mrproper: clean
	rm -rf $(EXEC)