printf.c,v

一个小型的操作系统,采用gcc进行开发,几千行的代码,方便初学者学习

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1.3
date	2004.06.01.02.59.13;	author root;	state Exp;
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date	2004.05.24.13.29.03;	author root;	state Exp;
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1.1
date	2004.05.24.12.34.29;	author root;	state Exp;
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1.3
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@add fprintf()
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@/*

  Snixos Project version 1.0, 2003.6
  (C) Copyright 2003-2004 Snallie Jockeyson <Snallie@@tom.com>
  All Rights Reserved.
  Distributed under the terms of the GNU General Public License.

  printf.c: implementation of c function printf() in SNIXOS project
  Author  : snallie@@tom.com
  Time    : 2003.6

  understood printf escape sequence:
  %c = char     %d = signed int    %x = unpaded hex
  %s = string   %0x = padded hex   %o = octal 
  %b = binary
*/

/* 	$Id: printf.c,v 1.2 2004/05/24 13:29:03 root Exp $	 */

#ifndef lint
static char vcid[] = "$Id: printf.c,v 1.2 2004/05/24 13:29:03 root Exp $";
#endif				/* lint */

#include "stdarg.h"
#include "stdio.h"
#include "ctype.h"
#include "io.h"
#include "mem.h"
#include "fatfs.h"

#define RESERVEDLINES 1		// head line reserved as status bar, 0 means the whole screen
				//  will be scrolled 
#define XUPPER 1
#define XLOWER 0
// Video Card I/O ports
#define TEXT_INDEX      0x03D4
#define TEXT_DATA       0x03D5
// Video Card Index Registers
#define TEXT_CURSOR_LO  0x0F
#define TEXT_CURSOR_HI  0x0E

static void printChar(char **str, int *len, char c);
static void printStr(char **str, int *len, char *pstr);
static void printInt(char **str, int *len, int num, int width);
static void printHex(char **str, int *len, unsigned int hex,
		     int padded, int style);
static void vaPrintf(char **str, int *len, char *fmt, va_list pvar);
static unsigned char getChar(int x, int y);
static unsigned char getAttrib(int x, int y);
static void scrollup(void);
static void writeChar(char c);
static void TXTWriteChar(char c);
static int intLen(int i, int radix);

static unsigned char *vidmem;	/* VGA video buffer for 80*25 color text mode */
static int vidx;		/* current cursor X position on screen */
static int vidy;		/* current cursor Y position on screen */
static unsigned char curAttrib;	/* current screent text attribute */
extern int videoMode;
/* 
 * console output functions
 */
void print_char(char c)
{
    int i = -1;
    printChar(NULL, &i, c);
}

void print_str(char *str)
{
    int i = -1;
    printStr(NULL, &i, str);
}

void print_int(int num)
{
    int i = -1;
    printInt(NULL, &i, num, 0);
}

void print_hex(unsigned int hex, int padded)
{
    int i = -1;
    printHex(NULL, &i, hex, padded, XLOWER);
}

void printf(char *fmt, ...)
{
    int i = -1;
    va_list pvar;
    va_start(pvar, fmt);
    vaPrintf(NULL, &i, fmt, pvar);
    va_end(pvar);
}

void sprintf(char *str, char *fmt, ...)
{
    int i = -1;

    va_list pvar;
    va_start(pvar, fmt);
    vaPrintf(&str, &i, fmt, pvar);
    va_end(pvar);
}

void snprintf(char *str, int len, char *fmt, ...)
{
    va_list pvar;
    va_start(pvar, fmt);
    vaPrintf(&str, &len, fmt, pvar);
    va_end(pvar);
}

int fprintf(FILE * fp, char *fmt, ...)
{

    char nstr[100];
    int i = -1;
    char *str = nstr;
    va_list pvar;
    va_start(pvar, fmt);
    vaPrintf(&str, &i, fmt, pvar);
    va_end(pvar);

    i = 0;
    while (*(str + i)) {
	Mfputc(*(str + i), fp);
	printf("%c", *(str + i));
	i++;
    }
    return i;
}


/* 
 * base functions for printf implementation
 */
static void printChar(char **str, int *len, char c)
{
    if (str) {
	if (*len != 0) {
	    *(*str)++ = c;
	    (*len)--;
	}
    } else {
	writeChar(c);
    }
}

static void printStr(char **str, int *len, char *pstr)
{
    while (*pstr) {
	printChar(str, len, *pstr);
	pstr++;
    }
}

/*
printInt()
print the num in decimal mode
*/
static void printInt(char **str, int *len, int num, int width)
{
    char nstr[12];
    int i = 10, j = 0;

    if (num < 0) {
	printChar(str, len, '-');
	printInt(str, len, -1 * num, width - 1);
	return;
    }
    nstr[11] = '\0';

    while (i > 0) {
	nstr[i % 11] = '0' + (num % 10);
	num /= 10;
	i--;
	if ((j >= width - 1) && (num <= 0))
	    break;
	else
	    j++;
    }
    printStr(str, len, nstr + i + 1);
}

/*
printHex()
printf the hex in hexadecimal mode
 */
static void printHex(char **str, int *len, unsigned int hex,
		     int pad, int style)
{
    char nstr[14];
    int i = 12, j;
    nstr[13] = '\0';

    pad--;
    for (j = 0; j < 8; j++) {
	if ((hex % 16) < 10)
	    nstr[i] = '0' + (hex % 16);
	else
	    nstr[i] = ((style == XLOWER) ? 'a' : 'A') + ((hex % 16) - 10);
	hex /= 16;
	i--;
	if ((j >= pad) && (hex <= 0))
	    break;
    }
    printStr(str, len, nstr + i + 1);
}

/*
void printOct(char **str, int *len, unsigned int num)
print the integer num in octal mode
 */
static void printOct(char **str, int *len, unsigned int num)
{
    int octLen = intLen(num, 8), i;

    char *octbuf = (char *) malloc((octLen + 1) * sizeof(char));
    if (octbuf == NULL) {
	printf("malloc failed in printOct\n");
	return;
    }
    i = octLen - 1;
    octbuf[octLen] = '\0';
    while (num) {
	octbuf[i % octLen] = num % 8 + '0';
	num /= 8;
	i--;
    }
    printStr(str, len, octbuf + i + 1);
    free(octbuf);
}

/*
void printBin(char **str, int *len, unsigned int num)
print the integer num in binary mode
 */
static void printBin(char **str, int *len, unsigned int num)
{
    int len2;
    int binLen = intLen(num, 2), i;

    char *binbuf =
	(char *) malloc(((binLen - 1) / 8 + 1) * 8 * sizeof(char) +
			sizeof(char));
    if (binbuf == NULL) {
	printf("malloc failed in printBin\n");
	return;
    }

    len2 = ((binLen - 1) / 8 + 1) * 8 * sizeof(char) + sizeof(char);
    i = ((binLen - 1) / 8 + 1) * 8 * sizeof(char) - 1;
    binbuf[((binLen - 1) / 8 + 1) * 8 * sizeof(char)] = '\0';
    while (i >= 0) {
	binbuf[i % len2] = num % 2 + '0';
	num /= 2;
	i--;
    }
    printStr(str, len, binbuf + i + 1);
    free(binbuf);
}


static void vaPrintf(char **str, int *len, char *fmt, va_list pvar)
{
    while (*fmt) {
	if (*fmt == '%') {
	    fmt++;
	    if (!*fmt) {
		if (str) {	/*  add end of line to array tp for sprintf(tp,char * ,...) */
		    printChar(str, len, '\0');
		}
		return;
	    }
	    switch (*fmt) {
	    case 's':		/* %s */
		printStr(str, len, va_arg(pvar, char *));
		break;

	    case 'c':		/* %c */
		printChar(str, len, va_arg(pvar, char));
		break;

	    case 'd':		/* %d */
		printInt(str, len, va_arg(pvar, int), 0);
		break;

	    case 'x':
	    case 'X':		/* %x or %X */
		printHex(str, len, va_arg(pvar, unsigned int), 0,
			 (*fmt == 'x') ? XLOWER : XUPPER);
		break;

	    case 'o':		/* %o */
		printOct(str, len, va_arg(pvar, unsigned int));
		break;

	    case 'b':		/* %b , binary output for number */
		printBin(str, len, va_arg(pvar, unsigned int));
		break;

	    case '0':		/* %0x %0X %0d */
		fmt++;
		switch (*fmt) {
		case 'x':
		case 'X':
		    printHex(str, len,
			     va_arg(pvar, unsigned int), 8,
			     (*fmt == 'x') ? XLOWER : XUPPER);
		    goto ret1;
		case 'd':
		    printInt(str, len, va_arg(pvar, int), 10);
		    goto ret1;
		}

		if (isdigit(*fmt)) {
		    int width = 0;
		    while (isdigit(*fmt)) {
			width = (width * 10 + (*fmt) - '0');
			fmt++;
		    }

		    if (*fmt == 'x' || *fmt == 'X') {
			printHex(str, len,
				 va_arg(pvar, unsigned int), width,
				 *fmt == 'x' ? XLOWER : XUPPER);
		    } else if (*fmt == 'd') {
			printInt(str, len, va_arg(pvar, int), width);
		    }
		}
	      ret1:
		break;

	    case '1':
	    case '2':
	    case '3':
	    case '4':
	    case '5':
	    case '6':
	    case '7':
	    case '8':
	    case '9':		/* %12x %12X %12d %12s %12c */
		if (isdigit(*fmt)) {
		    int width;
		    for (width = 0; isdigit(*fmt); fmt++) {
			width = (width * 10 + (*fmt) - '0');
		    }

		    if (*fmt == 'x' || *fmt == 'X') {
			printHex(str, len,
				 va_arg(pvar, unsigned int), width,
				 *fmt == 'x' ? XLOWER : XUPPER);
		    } else if (*fmt == 'd') {
			int num = va_arg(pvar, int);
			int length = intLen(num, 10);
			while (width > length) {
			    printChar(str, len, ' ');
			    width--;
			}
			printInt(str, len, num, length);

		    } else if (*fmt == 's') {
			char *strs = va_arg(pvar, char *);
			int strSize = strlen(strs);
			while (width - strSize > 0) {
			    printChar(str, len, ' ');
			    strSize++;
			}
			printStr(str, len, strs);
		    } else if (*fmt == 'c') {
			width -= 1;
			while (width > 0) {
			    printChar(str, len, ' ');
			    width--;
			}
			printChar(str, len, va_arg(pvar, char));
		    }
		}
		break;

	    case '-':		/* %-12s  %-12d  %-12c , left aligned */
		fmt++;
		if (isdigit(*fmt)) {
		    int width = 0;
		    while (isdigit(*fmt)) {
			width = (width * 10 + (*fmt) - '0');
			fmt++;
		    }

		    if (*fmt == 's') {
			char *strs = va_arg(pvar, char *);
			int strSize = strlen(strs);
			printStr(str, len, strs);
			while (width - strSize > 0) {
			    printChar(str, len, ' ');
			    strSize++;
			}
		    } else if (*fmt == 'd') {
			int num = va_arg(pvar, int);
			int length = intLen(num, 10);
			printInt(str, len, num, length);
			while (width - length > 0) {
			    printChar(str, len, ' ');
			    length++;
			}
		    } else if (*fmt == 'c') {
			printChar(str, len, va_arg(pvar, char));
			width -= 1;
			while (width > 0) {
			    printChar(str, len, ' ');
			    width--;
			}
		    }
		}
		break;

	    case '%':		/* %% */
		printChar(str, len, '%');
		fmt++;
		break;

	    default:
		break;

	    }
	} else {
	    printChar(str, len, *fmt);
	}
	fmt++;
    }				/* while(*fmt) */

    if (str) {			/* add end of line to array tp for sprintf(tp,char *fmt, ...) */
	printChar(str, len, '\0');
    }
}

/*
int intLen(int i, int radix) 
    return the count of i's digit which is beneath 
    the most significant digit in the desired radix.
 */
static int intLen(int i, int radix)
{
    int len = 0;
    if (i < 0) {
	return intLen(-i, radix);
    }
    do {
	i /= radix;
	len++;
    } while (i);
    return len;
}

/* VGA screen manipulation */
void screen_init(void)
{
    int i, j;
    vidmem = (unsigned char *) 0xb8000;
    set_attrib(ATTRIB_WHITE | ATTRIB_BLACK_BG);

    for (i = 0; i < 80; i++) {
	for (j = 0; j < 25; j++) {
	    screen_putchar(i, j, ' ', curAttrib);
	}
    }
    //line 1 reserved as status bar
    screen_gotoxy(0, 0 + RESERVEDLINES);
}

void screen_gotoxy(int x, int y)
{
    short pos = y * 80 + x;
    vidx = x;
    vidy = y;

    outb(TEXT_CURSOR_LO, TEXT_INDEX);	// access lo cursor data reg
    outb((char) pos, TEXT_DATA);
    outb(TEXT_CURSOR_HI, TEXT_INDEX);	// access hi cursor data reg
    outb((unsigned char) (pos >> 8), TEXT_DATA);
}

void screen_putchar(int x, int y, unsigned char c, unsigned char attrib)
{
    vidmem[((x) + (y) * 80) * 2] = c;
    vidmem[(((x) + (y) * 80) * 2) + 1] = attrib;
}

static unsigned char getChar(int x, int y)
{
    return vidmem[((x) + (y) * 80) * 2];
}

static unsigned char getAttrib(int x, int y)
{
    return vidmem[(((x) + (y) * 80) * 2) + 1];
}

static void scrollup(void)
{
    unsigned int org = (unsigned int) vidmem + (RESERVEDLINES + 1) * 160;
    unsigned int dst = (unsigned int) vidmem + RESERVEDLINES * 160;
    unsigned int cnt = 2000 - 80 * (RESERVEDLINES + 1);
    unsigned int cnt2 = 80;	/* characters to be displaed at the bottom line on screen */
    unsigned int dst2 = (unsigned int) vidmem + 24 * 80 * 2;	/* bottom line address in vidram */
    asm("cld\n\t" "rep\n\t" "movsl\n\t"::"c"(cnt), "D"(dst), "S"(org));
    asm("cld\n\t"
	"rep\n\t" "stosw\n\t"::"a"(0x0720), "c"(cnt2), "D"(dst2),
	"S"(org));
}

static void writeChar(char c)
{
    switch (videoMode) {
    case VIDTEXT_80X25:
	TXTWriteChar(c);
	break;

    case VIDGRAPH_640X480:

	VGAWriteChar(c);
	break;
    }
}


static void TXTWriteChar(char c)
{
    if (c == '\n') {		// CR LF
	screen_gotoxy(0, ++vidy);	// screen_gotoxy(ycord,xcord)
    } else if (c == '\t') {	// horizontal Tab
	screen_gotoxy(vidx += 4, vidy);
    } else if (c == '\b') {	// backspace
	screen_gotoxy(vidx -= 1, vidy);
	writeChar(' ');
	screen_gotoxy(vidx -= 1, vidy);
	return;
    } else {
	screen_putchar(vidx, vidy, (unsigned char) c, curAttrib);
	screen_gotoxy(++vidx, vidy);
    }

    // off right edge
    if (vidx > 79) {
	screen_gotoxy(0, ++vidy);
    }
    // off bottom
    if (vidy > 24) {
	scrollup();
	screen_gotoxy(vidx, 24);
    }

}

void set_attrib(unsigned char attrib)
{
    curAttrib = attrib;
}
@


1.2
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@add comments to some auxilary function
@
text
@d18 1
a18 1
/* 	$Id$	 */
d21 2
a22 2
static char vcid[] = "$Id$";
#endif /* lint */
d29 1
d46 1
a46 1
			   int padded, int style);
d52 1
d59 1
a59 1

d114 21
d191 1
a191 1
			   int pad, int style)
d271 1
a271 1
		if (str){	/*  add end of line to array tp for sprintf(tp,char * ,...)*/
d292 1
a292 1
			       (*fmt == 'x') ? XLOWER : XUPPER);
d309 2
a310 2
				   va_arg(pvar, unsigned int), 8,
				   (*fmt == 'x') ? XLOWER : XUPPER);
d326 2
a327 2
				       va_arg(pvar, unsigned int), width,
				       *fmt == 'x' ? XLOWER : XUPPER);
d352 2
a353 2
				       va_arg(pvar, unsigned int), width,
				       *fmt == 'x' ? XLOWER : XUPPER);
d431 1
a431 1
    } /* while(*fmt) */
d433 1
a433 1
    if (str){			/* add end of line to array tp for sprintf(tp,char *fmt, ...) */
d446 1
a446 1
    if (i < 0){
d515 15
d553 1
a559 7







@


1.1
log
@Initial revision
@
text
@d12 1
a12 1
  understood printf escape chars:
d18 6
d34 6
a52 8
// Video Card I/O ports
#define TEXT_INDEX      0x03D4
#define TEXT_DATA       0x03D5

// Video Card Index Registers
#define TEXT_CURSOR_LO  0x0F
#define TEXT_CURSOR_HI  0x0E

d113 1
a113 1
 * core functions
d135 4
a159 1

d163 4
a174 1

a184 1

a185 1

d188 4
d212 4
a217 1

a241 1

a306 1

a307 2


a325 46
		    /*
		       switch (*fmt) {
		       case 'x':
		       case 'X':
		       printHex(str, len,
		       va_arg(pvar, unsigned int), width,
		       *fmt == 'x' ? XLOWER : XUPPER);
		       break;

		       case 'd':
		       {
		       int num = va_arg(pvar, int);
		       int length = intLen(num, 10);
		       while (width > length) {
		       printf("%c", ' ');
		       width--;
		       }
		       printf("%d", num);
		       }
		       break;

		       case 's':
		       {
		       char *strs = va_arg(pvar, char *);
		       int strSize = strlen(strs);
		       while (width > strSize) {
		       printf("%c", ' ');
		       strSize++;
		       }
		       printf("%s", strs);
		       }
		       break;

		       case 'c':
		       {
		       width -= 1;
		       while (width > 0) {
		       printf("%c", ' ');
		       width--;
		       }
		       printf("%c", va_arg(pvar, char));
		       }
		       break;

		       }
		     */
a355 2


a356 1

a383 1

d409 1
d415 5
d423 1
a423 1
    if (i < 0)
d425 1
a432 1

a484 1

@