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OS/pintos-env/pintos/lib/user/console.c

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#include <stdio.h>
#include <string.h>
#include <syscall.h>
#include <syscall-nr.h>
/* The standard vprintf() function,
which is like printf() but uses a va_list. */
int
vprintf (const char *format, va_list args)
{
return vhprintf (STDOUT_FILENO, format, args);
}
/* Like printf(), but writes output to the given HANDLE. */
int
hprintf (int handle, const char *format, ...)
{
va_list args;
int retval;
va_start (args, format);
retval = vhprintf (handle, format, args);
va_end (args);
return retval;
}
/* Writes string S to the console, followed by a new-line
character. */
int
puts (const char *s)
{
write (STDOUT_FILENO, s, strlen (s));
putchar ('\n');
return 0;
}
/* Writes C to the console. */
int
putchar (int c)
{
char c2 = c;
write (STDOUT_FILENO, &c2, 1);
return c;
}
/* Auxiliary data for vhprintf_helper(). */
struct vhprintf_aux
{
char buf[64]; /* Character buffer. */
char *p; /* Current position in buffer. */
int char_cnt; /* Total characters written so far. */
int handle; /* Output file handle. */
};
static void add_char (char, void *);
static void flush (struct vhprintf_aux *);
/* Formats the printf() format specification FORMAT with
arguments given in ARGS and writes the output to the given
HANDLE. */
int
vhprintf (int handle, const char *format, va_list args)
{
struct vhprintf_aux aux;
aux.p = aux.buf;
aux.char_cnt = 0;
aux.handle = handle;
__vprintf (format, args, add_char, &aux);
flush (&aux);
return aux.char_cnt;
}
/* Adds C to the buffer in AUX, flushing it if the buffer fills
up. */
static void
add_char (char c, void *aux_)
{
struct vhprintf_aux *aux = aux_;
*aux->p++ = c;
if (aux->p >= aux->buf + sizeof aux->buf)
flush (aux);
aux->char_cnt++;
}
/* Flushes the buffer in AUX. */
static void
flush (struct vhprintf_aux *aux)
{
if (aux->p > aux->buf)
write (aux->handle, aux->buf, aux->p - aux->buf);
aux->p = aux->buf;
}