C语言编程技巧汇萃

/*从键盘中读取字符 功能：按下普通键时，返回其ASCII码 扫描码CODE=0*/
int INKEY(int *code)
{
int m;
while(!bioskey(1))/*可加入无按键时代码*/;
*code=bioskey(0);
m=*code*255;
if(!m) m=*code>>8;
*code=*code&255;
return m;
}

/*获取机器日期*/
int DATE(char *s,char type)
{
char dat[30];
int num;
struct tm *tblock;
time_t t;
t=time(NULL);
tblock=localtime(&t);
strcpy(dt,asctime(tblock));
strcpy(s,"");
switch(type)
{
case 'N':
num=(*tblock).tm_year 1900;
itoa(num,s,10);
break;
case 'Y':
num=(*tblock).tm_mon 1;
itoa(num,s,10);
break;
case 'R':
num=(*tblock).tm_mday;
itoa(num,s,10);
break;
case 'S':
strcpy(dt,asctime(tblock));
MID(s,dt,12,8);
break;
}
}
return num;
}

/*将浮点数转化为字符串*/
/* 参数说明 data:需转换的浮点数；s:输出字符串；len:转换后的长度*/
void f_to_s(double data,char *s,int len)
{
int dec,sign,i;
char *s1,s2[100],s3[100];
s1=0;
s2[0]=0;
s3[0]=0;
s1=fcvt(data,len,&dec,&sign);
if (!sign&&data>=1)
{
MID(s2,s1,dec 1,-1);
MID(s3,s1,1,dec);
strcpy(s," ");
strcat(s,s3);
strcat(s,".");
strcat(s,s2);
}
if (sign&&fabs(data)>=1)
{
MID(s2,s1,dec 1,-1);
strcpy(s,"-");
MID(s3,s1,1,dec);
strcat(s,s3);
strcat(s,".");
strcat(s,s2);
}
if (!sign&&dec==0)
{
strcpy(s," 0.");
strcat(s,s1);
}
if (sign&&dec==0)
{
strcpy(s,"-0.");
strcat(s,s1);
}
if (!sign&&dec<0)
{
strcpy(s," 0.");
for(i=1;i<=fabs(dec);i )
strcat(s,"0");
strcat(s,s1);
}
if (sign&&dec<0)
{
strcpy(s,"-0.");
for(i=1;i<=fabs(dec);i )
strcat(s,"0");
strcat(s,s1);
}
if (strlen(s)>len) s[len]=0;
}

/*清除屏幕*/
void CLSXY(int color,int x,int y,int xl,int yl)
{
int x1,y1;
union REGS r;
if(x<1||y<1) return;
y--;
x--;
y1=y yl-1;
x1=x xl-1;
if (y1>25||x1>80)
return;
r.h.ah=6; /*子功能号*/
r.h.al=0; /*滚动行数*/
r.h.ch=y;
r.h.cl=x;
r.h.dh=y1;
r.h.dl=x1;
r.h.bh=color*16;
int86(16,&r,&r);
}