<P>函数名: bdosptr
功能: DOS系统调用
用法: int bdosptr(int dosfun, void *argument, unsigned dosal);
程序例: <P>#include <string.h>
#include <stdio.h>
#include <dir.h>
#include <dos.h>
#include <errno.h>
#include <stdlib.h> <P>#defineBUFLEN80 <P>int main(void)
{
charbuffer;
int test; <P> printf("Enter full pathname of a directory\n");
gets(buffer); <P> test = bdosptr(0x3B,buffer,0);
if(test)
{
printf("DOS error message: %d\n", errno);
/* See errno.h for error listings */
exit (1);
} <P> getcwd(buffer, BUFLEN);
printf("The current directory is: %s\n", buffer); <P> return 0;
}
</P>
<P>函数名: bioscom
功能: 串行I/O通信
用法: int bioscom(int cmd, char abyte, int port);
程序例: <P>#include <bios.h>
#include <conio.h> <P>#define COM1 0
#define DATA_READY 0x100
#define TRUE 1
#define FALSE 0 <P>#define SETTINGS ( 0x80 | 0x02 | 0x00 | 0x00) <P>int main(void)
{
int in, out, status, DONE = FALSE; <P> bioscom(0, SETTINGS, COM1);
cprintf("... BIOSCOM to exit ...\n");
while (!DONE)
{
status = bioscom(3, 0, COM1);
if (status & DATA_READY)
if ((out = bioscom(2, 0, COM1) & 0x7F) != 0)
putch(out);
if (kbhit())
{
if ((in = getch()) == '\x1B')
DONE = TRUE;
bioscom(1, in, COM1);
}
}
return 0;
}
</P>
<P>函数名: biosdisk
功能: 软硬盘I/O
用法: int biosdisk(int cmd, int drive, int head, int track, int sector
int nsects, void *buffer);
程序例: <P>#include <bios.h>
#include <stdio.h> <P>int main(void)
{
int result;
char buffer; <P> printf("Testing to see if drive a: is ready\n");
result = biosdisk(4,0,0,0,0,1,buffer);
result &= 0x02;
(result) ? (printf("Drive A: Ready\n")) :
(printf("Drive A: Not Ready\n")); <P> return 0;
}
</P>
<P>函数名: biosequip
功能: 检查设备
用法: int biosequip(void);
程序例: <P>#include <bios.h>
#include <stdio.h> <P>int main(void)
{
int result;
char buffer; <P> printf("Testing to see if drive a: is ready\n");
result = biosdisk(4,0,0,0,0,1,buffer);
result &= 0x02;
(result) ? (printf("Drive A: Ready\n")) :
(printf("Drive A: Not Ready\n")); <P> return 0;
}
</P>
<P>函数名: bioskey
功能: 直接使用BIOS服务的键盘接口
用法: int bioskey(int cmd);
程序例: <P>#include <stdio.h>
#include <bios.h>
#include <ctype.h> <P>#define RIGHT0x01
#define LEFT 0x02
#define CTRL 0x04
#define ALT 0x08 <P>int main(void)
{
int key, modifiers; <P> /* function 1 returns 0 until a key is pressed */
while (bioskey(1) == 0); <P> /* function 0 returns the key that is waiting */
key = bioskey(0); <P> /* use function 2 to determine if shift keys were used */
modifiers = bioskey(2);
if (modifiers)
{
printf("[");
if (modifiers & RIGHT) printf("RIGHT");
if (modifiers & LEFT)printf("LEFT");
if (modifiers & CTRL)printf("CTRL");
if (modifiers & ALT) printf("ALT");
printf("]");
}
/* print out the character read */
if (isalnum(key & 0xFF))
printf("'%c'\n", key);
else
printf("%#02x\n", key);
return 0;
}
</P>
<P>函数名: biosmemory
功能: 返回存储块大小
用法:int biosmemory(void);
程序例: <P>#include <stdio.h>
#include <bios.h> <P>int main(void)
{
int memory_size; <P> memory_size = biosmemory();/* returns value up to 640K */
printf("RAM size = %dK\n",memory_size);
return 0;
}
</P>
<P>函数名: biosprint
功能: 直接使用BIOS服务的打印机I/O
用法: int biosprint(int cmd, int byte, int port);
程序例: <P>#include <stdio.h>
#include <conio.h>
#include <bios.h> <P>int main(void)
{
#define STATUS2 /* printer status command */
#define PORTNUM 0 /* port number for LPT1 */ <P> int status, abyte=0; <P> printf("Please turn off your printer.Press any key to continue\n");
getch();
status = biosprint(STATUS, abyte, PORTNUM);
if (status & 0x01)
printf("Device time out.\n");
if (status & 0x08)
printf("I/O error.\n"); <P> if (status & 0x10)
printf("Selected.\n");
if (status & 0x20)
printf("Out of paper.\n"); <P> if (status & 0x40)
printf("Acknowledge.\n");
if (status & 0x80)
printf("Not busy.\n"); <P> return 0;
}
</P>
<P>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: <P>#include <stdio.h>
#include <bios.h>
#include <time.h>
#include <conio.h> <P>int main(void)
{
long bios_time; <P> 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); <P> gotoxy(50, 1);
cprintf("%lu", bios_time); <P> gotoxy(50, 2);
cprintf("%.4f", bios_time / CLK_TCK); <P> gotoxy(50, 3);
cprintf("%.4f", bios_time / CLK_TCK / 60); <P> gotoxy(50, 4);
cprintf("%.4f", bios_time / CLK_TCK / 3600);
}
return 0;
}
</P>
<P>函数名: brk
功能: 改变数据段空间分配
用法: int brk(void *endds);
程序例: <P>#include <stdio.h>
#include <alloc.h> <P>int main(void)
{
char *ptr; <P> 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;
}
</P>
<P>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: <P>#include <stdlib.h>
#include <stdio.h> <P>#define NELEMS(arr) (sizeof(arr) / sizeof(arr)) <P>int numarray[] = {123, 145, 512, 627, 800, 933}; <P>int numeric (const int *p1, const int *p2)
{
return(*p1 - *p2);
} <P>int lookup(int key)
{
int *itemptr; <P> /* 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);
} <P>int main(void)
{
if (lookup(512))
printf("512 is in the table.\n");
else
printf("512 isn't in the table.\n"); <P> return 0;
}
</P>