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/* ########################################################### */
/* This Software is licensed under the GPL licensed Version 2, */
/* please read http://www.gnu.org/copyleft/gpl.html. */
/* ########################################################### */
/* ************************************************************************* */
/* Custom fgetc/ungetc implementation able to unget more than one character. */
/* ************************************************************************* */
#include <stdio.h>
#include "fgetc.h"
enum
{
GETC_BUFF_SIZE = 16
};
static char getc_buffer[GETC_BUFF_SIZE] = { '\0' };
static long next_buffer_pos = 0; /* Next free position in the getc buffer. */
/* ======================================== */
/* Gets a (possibly pushed-back) character. */
/* ======================================== */
int
my_fgetc(FILE * input)
{
return (next_buffer_pos > 0) ? getc_buffer[--next_buffer_pos] : fgetc(input);
}
/* =============================== */
/* Pushes character back on input. */
/* =============================== */
void
my_ungetc(int c, FILE * input)
{
if (next_buffer_pos >= GETC_BUFF_SIZE)
fprintf(stderr, "Error: cannot push back more than %d characters\n",
GETC_BUFF_SIZE);
else
{
getc_buffer[next_buffer_pos++] = c;
if (feof(input))
clearerr(input); /* No more EOF. */
}
}
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