副标题#e#
函数名: harderr
成果: 成立一个硬件错误处理惩罚措施
用法: void harderr(int (*fptr)());
措施例:
/*This program will trap disk errors and prompt
the user for action. Try running it with no
disk in drive A: to invoke its functions.*/
#include
#include
#include
#define IGNORE 0
#define RETRY 1
#define ABORT 2
int buf[500];
/*define the error messages for trapping disk problems*/
static char *err_msg[] = {
"write protect",
"unknown unit",
"drive not ready",
"unknown command",
"data error (CRC)",
"bad request",
"seek error",
"unknown media type",
"sector not found",
"printer out of paper",
"write fault",
"read fault",
"general failure",
"reserved",
"reserved",
"invalid disk change"
};
error_win(char *msg)
{
int retval;
cputs(msg);
/*prompt for user to press a key to abort, retry, ignore*/
while(1)
{
retval= getch();
if (retval == 'a' || retval == 'A')
{
retval = ABORT;
break;
}
if (retval == 'r' || retval == 'R')
{
retval = RETRY;
break;
}
if (retval == 'i' || retval == 'I')
{
retval = IGNORE;
break;
}
}
return(retval);
}
/*pragma warn -par reduces warnings which occur
due to the non use of the parameters errval,
bp and si to the handler.*/
#pragma warn -par
int handler(int errval,int ax,int bp,int si)
{
static char msg[80];
unsigned di;
int drive;
int errorno;
di= _DI;
/*if this is not a disk error then it was
another device having trouble*/
if (ax < 0)
{
/* report the error */
error_win("Device error");
/* and return to the program directly requesting abort */
hardretn(ABORT);
}
/* otherwise it was a disk error */
drive = ax & 0x00FF;
errorno = di & 0x00FF;
/* report which error it was */
sprintf(msg, "Error: %s on drive %c\r\nA)bort, R)etry, I)gnore: ",
err_msg[errorno], 'A' + drive);
/*
return to the program via dos interrupt 0x23 with abort, retry,
or ignore as input by the user.
*/
hardresume(error_win(msg));
return ABORT;
}
#pragma warn +par
int main(void)
{
/*
install our handler on the hardware problem interrupt
*/
harderr(handler);
clrscr();
printf("Make sure there is no disk in drive A:\n");
printf("Press any key ....\n");
getch();
printf("Trying to access drive A:\n");
printf("fopen returned %p\n",fopen("A:temp.dat", "w"));
return 0;
}
#p#副标题#e#
函数名: hardresume
成果: 硬件错误处理惩罚函数
用法: void hardresume(int rescode);
措施例:
/* This program will trap disk errors and prompt the user for action. */
/* Try running it with no disk in drive A: to invoke its functions */
#include
#include
#include
#define IGNORE 0
#define RETRY 1
#define ABORT 2
int buf[500];
/* define the error messages for trapping disk problems */
static char *err_msg[] = {
"write protect",
"unknown unit",
"drive not ready",
"unknown command",
"data error (CRC)",
"bad request",
"seek error",
"unknown media type",
"sector not found",
"printer out of paper",
"write fault",
"read fault",
"general failure",
"reserved",
"reserved",
"invalid disk change"
};
error_win(char *msg)
{
int retval;
cputs(msg);
/* prompt for user to press a key to abort, retry, ignore */
while(1)
{
retval= getch();
if (retval == 'a' || retval == 'A')
{
retval = ABORT;
break;
}
if (retval == 'r' || retval == 'R')
{
retval = RETRY;
break;
}
if (retval == 'i' || retval == 'I')
{
retval = IGNORE;
break;
}
}
return(retval);
}
/* pragma warn -par reduces warnings which occur due to the non use */
/* of the parameters errval, bp and si to the handler. */
#pragma warn -par
int handler(int errval,int ax,int bp,int si)
{
static char msg[80];
unsigned di;
int drive;
int errorno;
di= _DI;
/* if this is not a disk error then it was another device having trouble */
if (ax < 0)
{
/* report the error */
error_win("Device error");
/* and return to the program directly
requesting abort */
hardretn(ABORT);
}
/* otherwise it was a disk error */
drive = ax & 0x00FF;
errorno = di & 0x00FF;
/* report which error it was */
sprintf(msg, "Error: %s on drive %c\r\nA)bort, R)etry, I)gnore: ",
err_msg[errorno], 'A' + drive);
/* return to the program via dos interrupt 0x23 with abort, retry */
/* or ignore as input by the user. */
hardresume(error_win(msg));
return ABORT;
}
#pragma warn +par
int main(void)
{
/* install our handler on the hardware problem interrupt */
harderr(handler);
clrscr();
printf("Make sure there is no disk in drive A:\n");
printf("Press any key ....\n");
getch();
printf("Trying to access drive A:\n");
printf("fopen returned %p\n",fopen("A:temp.dat", "w"));
return 0;
}
函数名: highvideo
成果: 选择高亮度文本字符
用法: void highvideo(void);
措施例:
#p#分页标题#e#
#include
int main(void)
{
clrscr();
lowvideo();
cprintf("Low Intensity text\r\n");
highvideo();
gotoxy(1,2);
cprintf("High Intensity Text\r\n");
return 0;
}
函数名: hypot
成果: 计较直角三角形的斜边长
用法: double hypot(double x, double y);
措施例:
#include
#include
int main(void)
{
double result;
double x = 3.0;
double y = 4.0;
result = hypot(x, y);
printf("The hypotenuse is: %lf\n", result);
return 0;
}
