olibc/src/stdio.c

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

int putchar(int c) {
  sys_write(stdout, &c, 1);
  return (unsigned char)c;
}

int puts(const char *s) {
  int i = 0;
  while(s[i] != '\0') {
    putchar(s[i]);
    i++;
  }
  putchar('\n');
  return 1; // FIXME
}

int vprintf(const char *restrict format, va_list ap) {
  char *s;
  int value;
  int size = 0;
  for (size_t i = 0; i < strlen(format); i++) {
    if (format[i] == '%') {
      i++;
      switch(format[i]) {
      case 'c':
	putchar((char) va_arg(ap, int));
	size++;
	break;
      case 's':
	s = va_arg(ap, char *);
	for (size_t j = 0; j < strlen(s); j++) {
	  putchar(s[j]);
	  size++;
	}
	break;
      case 'd':
	value = va_arg(ap, int);
	if (value == 0) {
	  putchar('0');
	  size++;
	} if (value < 0) {
	  putchar('-');
	  value *= (-1);
	  size++;
	}
	
	long long power = 1;
	
	while (value > power)
	  power *= 10;
	
	if (power >= 10)
	  power /= 10;
	
	while (value != 0) {
	  int digit = (int)(value / power);
	  putchar('0' + digit);
	  size++;
	  if (digit != 0)
	    value = value - digit * power;
	  if (power != 1)
	    power /= 10;
	}
	break;
      }
    } else {
      putchar(format[i]);
      size++;
    }
  }
  return size;
}

int printf(const char *restrict format, ...) {
  int size;
  va_list ap;
  va_start(ap, format);
  size = vprintf(format, ap);
  va_end(ap);
  return size;
}

#define O_RDWR 2 // FIXME
#define O_RDONLY 0
#define O_CREAT 64
#define O_TRUNC 512
#define O_WRONLY 1
#define O_APPEND 1024

#define EINVAL 22 // FIXME

FILE* fopen(const char *restrict pathname, const char *restrict mode) { // FIXME
  if (pathname == NULL)
    return (FILE*)NULL;
  int oflag;
  switch(mode[0]) { // TODO: add b and x mode (check C11 specifications)
  case 'r':
    if (strlen(mode) > 1 && mode[1] == '+')
      oflag = O_RDWR;
    else
      oflag = O_RDONLY;
    break;
  case 'w':
    if (strlen(mode) > 1 && mode[1] == '+')
      oflag = O_RDWR | O_CREAT | O_TRUNC;
    else
      oflag = O_WRONLY | O_CREAT | O_TRUNC;
    break;
  case 'a':
    if (strlen(mode) > 1 && mode[1] == '+')
      oflag = O_RDWR | O_CREAT | O_APPEND;
    else
      oflag = O_WRONLY | O_CREAT | O_APPEND;
    break;
  default:
    return (FILE*)EINVAL;
  }
  int fd = sys_open(pathname, oflag);
  if (fd == -1)
    return NULL;
  FILE *temp = malloc(sizeof(pathname) + sizeof(fd));
  temp->filename = (char*)pathname;
  temp->fd = fd;
  return temp;
}

int fclose(FILE *stream) {
  return sys_close(stream->fd);
}

int fgetc(FILE *stream) {
  char buf = '\0';
  sys_read(stream->fd, (void*)&buf, 1);
  return (buf == '\0') ? (unsigned int)-1 : (unsigned int)buf;
}

int getchar(void) {
  return fgetc(stdin);
}

char *fgets(char *restrict s, int n, FILE *restrict stream) {
  s = malloc(n);
  int i = 0;
  char c = '\0';
  while (i < n-1 && (c = fgetc(stream)) != -1 && (s[i++] = c) && c != '\n');
  return (strlen(s) == 0) ? NULL : s;
}