kolibrios-fun/programs/develop/ktcc/trunk/libctest/ungetc.c

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
//#include <errno.h>
//#include <limits.h>
//#include <unistd.h>
#include "test.h"

#define TEST(r, f, x, m) ( \
	errno = 0, ((r) = (f)) == (x) || \
	(t_error("%s failed (" m ")\n", #f, r, x, strerror(errno)), 0) )

#define TEST_S(s, x, m) ( \
	!strcmp((s),(x)) || \
	(t_error("[%s] != [%s] (%s)\n", s, x, m), 0) )

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

#define fgetc fgetc_dbg  
#define ungetc ungetc_dbg  

	
int fgetc_dbg(FILE* file)
{
	int c = 0, rc;
	
	rc = fread(&c, 1, 1, file);

	if (rc < 1) return EOF;

	return c;
}

int ungetc_dbg(int c,FILE* file)
{
	dword res;

    if(!file)
    {
        errno = E_INVALIDPTR;
        return EOF;
    }

	if ((file->mode & 3!=FILE_OPEN_READ) && (file->mode & FILE_OPEN_PLUS==0))
    {
        errno = E_ACCESS;
        return EOF;
    }

	if (file->filepos>file->filesize || file->filepos==0 || c == EOF || file->ungetc_buf != EOF)
	{
	    errno = E_EOF;
		return EOF;
	}
	
	file->ungetc_buf = c;
	file->filepos--;

	return c;
}

void mark(int n)
{
	n++;
}	
	

int main(void)
{
	int i;
	char a[100];
	FILE *f;

	TEST(i, !(f = fopen("_tmpfile.tmp","w+")), 0, "failed to create temp file %d!=%d (%s)");

	if (!f) return t_status;

	TEST(i, fprintf(f, "hello, world\n"), 13, "%d != %d (%m)");
	TEST(i, fseek(f, 0, SEEK_SET), 0, "%d != %d (%m)");

	TEST(i, feof(f), 0, "%d != %d");
	TEST(i, fgetc(f), 'h', "'%c' != '%c'");
	TEST(i, ftell(f), 1, "%d != %d");
	TEST(i, ungetc('x', f), 'x', "%d != %d");
	TEST(i, ftell(f), 0, "%d != %d");
	TEST(i, fscanf(f, "%[h]", a), 0, "got %d fields, expected %d");
	TEST(i, ftell(f), 0, "%d != %d");
mark(0x11);
printf("debug file ungetbuf=%d\n", f->ungetc_buf);
	TEST(i, fgetc(f), 'x', "'%c' != '%c'");  
	TEST(i, ftell(f), 1, "%d != %d");

	TEST(i, fseek(f, 0, SEEK_SET), 0, "%d != %d");
	TEST(i, ungetc('x', f), 'x', "%d != %d");
mark(0x22);
	TEST(i, fread(a, 1, sizeof a, f), 14, "read %d, expected %d"); 
	a[14] = 0;
	TEST_S(a, "xhello, world\n", "mismatch reading ungot character");

	TEST(i, fseek(f, 0, SEEK_SET), 0, "%d != %d");
	TEST(i, fscanf(f, "%[x]", a), 0, "got %d fields, expected %d");
	TEST(i, ungetc('x', f), 'x', "unget failed after fscanf: %d != %d");
	TEST(i, fgetc(f), 'x', "'%c' != '%c'");
mark(0x33);	
	TEST(i, ftell(f), 1, "%d != %d");
	TEST(i, fgetc(f), 'h', "'%c' != '%c'");

	printf("%s finished\n", __FILE__);
	fclose(f);
	return t_status;
}