stdio

stdio.c

/*
 * Alexis Daboville - 2011
 */

#include <fcntl.h>
#include <stdarg.h>
#include <stdbool.h>
#include <stdlib.h>
#include <sys/stat.h>
#include <unistd.h>

#include <string.h>

#include "stdio.h"

#define MAX_FILE 1024

/*
 * Pas de gestion des erreurs
 * Alloué un buffer en écriture dans _flsbuf si nécessaire.
 */
struct _iobuf _IOB[MAX_FILE] = {
    { 0, NULL, NULL, 0, _IOREAD, 0 },
    { 0, NULL, NULL, 0, _IOWRT | _IOLBF, 1 },
    { 0, NULL, NULL, 0, _IOWRT | _IONBF, 2 }
};

/*
 * Remplit le buffer de p, et alloue le buffer si ça n'a pas été fait.
 */
int _filbuf(FILE *p) {
    //si on a pas de buffer, on en alloue un
    if(!p->_base) {
        if(!p->_bufsiz) {
            p->_bufsiz = BUFSIZ;
        }

        p->_base = malloc(p->_bufsiz);
    }

    //on lit les carctères, et on place _ptr au début du buffer
    p->_cnt = read(p->_file, p->_base, p->_bufsiz);
    p->_ptr = p->_base;

    if(p->_cnt) {
        --p->_cnt;
        return *p->_ptr++;
    }

    return EOF;
}

/*
 * Flush le buffer de p, et affiche c.
 */
int _flsbuf(int c, FILE *p) {
    //si on est pas bufferisé, on écrit le carctère (e.g. stderr)
    if(p->_flag & _IONBF) {
        write(p->_file, &c, 1);
        return c;
    }

    //si on a pas de buffer, on en alloue un
    if(!p->_base) {
        if(!p->_bufsiz) {
            p->_bufsiz = BUFSIZ;
        }

        p->_ptr = p->_base = malloc(p->_bufsiz);
        p->_cnt = 0;

        //on ajoute le caractère au buffer
        return putc(c, p);
    }

    //si on est line buffered et que le buffer n'est pas plein
    //on le vide
    if(p->_flag & _IOLBF && -p->_cnt < p->_bufsiz) {
        write(p->_file, p->_base, -p->_cnt);
        p->_ptr = p->_base;
        p->_cnt = 0;
    }

    else {
        //s'il reste de la place dans le buffer on le vide (+1 pour le denier char)
        if(p->_cnt >= 0) {
            write(p->_file, p->_base, p->_ptr - p->_base + 1);
            p->_ptr = p->_base;
            p->_cnt = p->_bufsiz;
        }

        //le buffer est plein : on le vide, et on mets c dedans
        else {
            write(p->_file, p->_base, p->_ptr - p->_base);
            p->_ptr = p->_base;
            p->_cnt = p->_flag & _IOLBF ? 0 : p->_bufsiz;
            putc(c, p);
        }
    }

    return c;
}

/*
 * Force le flush du buffer de stream.
 */
int fflush(FILE *stream) {
    return stream->_cnt == 0 ? 0 :_flsbuf((int) *--stream->_ptr, stream);
}

/*
 * Ouvre le fichier à l'adresse path selon le mode mode, man 3 fopen
 * pour voir les modes disponibles.
 */

/*
 * Comment gérer r+, w+, a. avec un seul buffer ?
 */
FILE *fopen(const char *path, const char *mode) {
    int fd;

    if(strcmp(mode, "r") == 0) {
        fd = open(path, O_RDONLY);
        _IOB[fd]._flag = _IOREAD;
        _IOB[fd]._cnt = 0;
    }

    else if(strcmp(mode, "w") == 0) {
        fd = open(path, O_WRONLY | O_CREAT | O_TRUNC,
                S_IRUSR | S_IWUSR | S_IRGRP | S_IROTH);
        _IOB[fd]._flag = _IOWRT | _IOFBF; 
    }

    else if(strcmp(mode, "a") == 0) {
        fd = open(path, O_WRONLY | O_CREAT | O_APPEND,
                S_IRUSR | S_IWUSR | S_IRGRP | S_IROTH);
        _IOB[fd]._flag = _IOWRT | _IOFBF;
    }

    _IOB[fd]._bufsiz = 0;
    _IOB[fd]._ptr = _IOB[fd]._base = NULL;
    _IOB[fd]._file = fd;

    return &_IOB[fd];
}

/*
 * Ferme le fichier stream, et désalloue le buffer s'il
 * y en a un.
 */
int fclose(FILE *stream) {
    fflush(stream);

    if(stream->_base) {
        free(stream->_base);
    }

    return close(stream->_file);
}

/*
 * man 3 setbuf
 */
void setbuf(FILE *stream, char *buf) {
    setvbuf(stream, buf, buf ? _IOFBF : _IONBF, BUFSIZ);
}

/*
 * man 3 setvbuf
 */
int setvbuf(FILE *stream, char *buf, int mode, int size) {
    stream->_ptr = stream->_base = buf;
    stream->_bufsiz = size;

    stream->_flag &= (~_IOLBF | ~_IOFBF | ~_IONBF);
    stream->_flag |= mode;

    if(~stream->_flag & _IOLBF && stream->_flag & _IOWRT) {
        stream->_cnt = size;
    }

    else {
        stream->_cnt = 0;
    }

    return 0;
}

int _fprintf(FILE *stream, const char *format, va_list ap) {
    int a, i = 0, c, count = 0, base, j, mod;
    bool modifier = false, hexa = false;
    char *b, buff[8 * sizeof (int)];

    while(c = (int) format[i]) {
        if(modifier) {
            ++count;
            modifier = false;

            switch(c) {
                case '%':
                    putc(c, stream);
                    break;
                case 'c':
                    a = va_arg(ap, int);
                    putc(a, stream);
                    break;
                case 's':
                    b = va_arg(ap, char*);
                    --count;
                    while(*b) {
                        putc(*b, stream);
                        ++b;
                        ++count;
                    }
                    break;
                case 'x':
                    hexa = true;
                case 'd':
                    a = va_arg(ap, int);
                    base = hexa ? 16 : 10;
                    j = sizeof(buff);
                    b = buff;
                    b[--j] = 0;

                    if(a < 0) {
                        putc('-', stream);
                    }

                    do {
                        --j;
                        mod = a % base;
                        a /= base;
                        b[j] = mod + (mod < 10 ? '0' : 'a' - 10);
                    } while(a != 0);

                    b = buff + j;
                    while(*b) {
                        putc(*b, stream);
                        ++b;
                    }

                    hexa = false;
                    break;

                default:
                    return -1;
            }
        }

        else if(format[i] == '%') {
            modifier = true;    
        }

        else {
            ++count;
            putc(c, stream); 
        }

        ++i;
    }

    return count;
}

int fprintf(FILE *stream, const char *format, ...) {
    va_list ap;
    int c;

    va_start(ap, format);

    c = _fprintf(stream, format, ap);

    va_end(ap);
    return c;
}

int printf(const char *format, ...) {
    va_list ap;
    int c;

    va_start(ap, format);

    c = _fprintf(stdout, format, ap);

    va_end(ap);
    return c;
}

stdio.h

/***
 *
 * Re-ecriture des fonctions de base de stdio
 *
 *           Author: Erick Gallesio [eg@unice.fr]
 *    Creation date: 27-Oct-1992 09:28
 * Last file update:  6-Mar-2011 22:21 (eg)
 *
 */


/**** Ce qui suit est le fichier standard stdio.h de Sun OS 4.x
      (legerement modifie) ****/

# ifndef FILE
#define	BUFSIZ	1024
#define _SBFSIZ	8
extern	struct	_iobuf {
	int		_cnt;
	unsigned char*  _ptr;
	unsigned char*  _base;
	int		_bufsiz;
	short		_flag;
	char		_file;
} _IOB[];

#define _IOFBF	 0
#define	_IOREAD	 01
#define	_IOWRT	 02
#define	_IONBF	 04
#define	_IOMYBUF 010
#define	_IOEOF	 020
#define	_IOERR	 040
#define	_IOSTRG	 0100
#define	_IOLBF	 0200
#define	_IORW	 0400
#define	NULL	 ((void*) 0)
#define	FILE	 struct _iobuf
#define	EOF	 (-1)

#define	stdin	 (&_IOB[0])
#define	stdout	 (&_IOB[1])
#define	stderr	 (&_IOB[2])

#ifdef lint	/* so that lint likes (void)putc(a,b) */
extern int putc();
extern int getc();
#else
#define	getc(p)		(--(p)->_cnt>=0? ((int)*(p)->_ptr++):_filbuf(p))
#define putc(x, p)	(--(p)->_cnt >= 0 ?\
	(int)(*(p)->_ptr++ = (unsigned char)(x)) :\
	(((p)->_flag & _IOLBF) && -(p)->_cnt < (p)->_bufsiz ?\
		((*(p)->_ptr = (unsigned char)(x)) != '\n' ?\
			(int)(*(p)->_ptr++) :\
			_flsbuf(*(unsigned char *)(p)->_ptr, p)) :\
		_flsbuf((unsigned char)(x), p)))
#endif

#define	getchar()	getc(stdin)
#define	putchar(x)	putc((x),stdout)
#define	feof(p)		(((p)->_flag&_IOEOF)!=0)
#define	ferror(p)	(((p)->_flag&_IOERR)!=0)
#define	fileno(p)	((p)->_file)
#define	clearerr(p)	(void) ((p)->_flag &= ~(_IOERR|_IOEOF))


FILE *fopen(const char *path, const char *mode);
FILE *fdopen(int fd, const char *mode);
FILE *freopen(const char *path, const char *mode, FILE *stream);
int fclose(FILE *fp);

FILE *popen(const char *command, const char *type);
int pclose(FILE *stream);

FILE *tmpfile(void);

int fgetc(FILE *stream);
char *fgets(char *s, int size, FILE *stream);
char *gets(char *s);

int fputc(int c, FILE *stream);
int fputs(const char *s, FILE *stream);
int puts(const char *s);

int printf(const char *format, ...);
int fprintf(FILE *stream, const char *format, ...);
int sprintf(char *str, const char *format, ...);

void setbuf(FILE *stream, char *buf);
int setvbuf(FILE *stream, char *buf, int mode, int size);
# endif