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Turbo C 2.0、Borland C++库函数及用例(8) printf("Acknowledge.\n");
if (status & 0x80)
printf("Not busy.\n"); return 0;
}
函数名: biostime
功 能: 读取或设置BIOS时间
用 法: long biostime(int cmd, long newtime);
程序例:#include <stdio.h>
#include <bios.h>
#include <time.h>
#include <conio.h>int main(void)
{
long bios_time;
clrscr(); cprintf("The number of clock ticks since midnight\
is:\r\n");
cprintf("The number of seconds since midnight is:\r\n");
cprintf("The number of minutes since midnight is:\r\n");
cprintf("The number of hours since midnight is:\r\n");
cprintf("\r\nPress any key to quit:");
while(!kbhit())
{
bios_time = biostime(0, 0L); gotoxy(50, 1);
cprintf("%lu", bios_time); gotoxy(50, 2);
cprintf("%.4f", bios_time / CLK_TCK); gotoxy(50, 3);
cprintf("%.4f", bios_time / CLK_TCK / 60); gotoxy(50, 4);
cprintf("%.4f", bios_time / CLK_TCK / 3600);
}
return 0;
}
函数名: brk
功 能: 改变数据段空间分配
用 法: int brk(void *endds);
程序例:#include <stdio.h>
#include <alloc.h>int main(void)
{
char *ptr; printf("Changing allocation with brk()\n");
ptr = malloc(1); printf("Before brk() call:%lu bytes free\n",coreleft());
brk(ptr+1000);
printf(" After brk() call:%lu bytes free\n",coreleft());
return 0;
}
函数名: bsearch
功 能: 二分法搜索
用 法: void *bsearch( const void *key, const void *base,
size_t *nelem, size_t width,
int(*fcmp)(const void *, const *));
程序例:
#include <stdlib.h>
#include <stdio.h>
#define NELEMS(arr) (sizeof(arr) / sizeof(arr[0]))
int numarray[] = {123, 145, 512, 627, 800, 933};
int numeric (const int *p1, const int *p2)
{
return(*p1 - *p2);
}int lookup(int key)
{
int *itemptr; /* The cast of (int(*)(const void *,const void*))
is needed to avoid a type mismatch error at
compile time */
itemptr = bsearch (&key, numarray, NELEMS(numarray),
sizeof(int), (int(*)(const void *,const void *))numeric);
return (itemptr != NULL);
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