O.xml

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函数名:?open?

功??能:?打开一个文件用于读或写?

用??法:?int?open(char?*pathname,?int?access[,?int?permiss]);?

程序例:?

#include?<string.h>?
#include?<stdio.h>?
#include?<fcntl.h>?
#include?<io.h>?
int?main(void)?
{?
???int?handle;?
???char?msg[]?=?"Hello?world";?
???if?((handle?=?open("TEST.$$$",?O_CREAT?|?O_TEXT))?==?-1)?
???{?
??????perror("Error:");?
??????return?1;?
???}?
???write(handle,?msg,?strlen(msg));?
???close(handle);?
???return?0;?
}?
??
??

函数名:?outport?

功??能:?输出整数到硬件端口中?

用??法:?void?outport(int?port,?int?value);?

程序例:?

#include?<stdio.h>?
#include?<dos.h>?
int?main(void)?
{?
???int?value?=?64;?
???int?port?=?0;?
???outportb(port,?value);?
???printf("Value?%d?sent?to?port?number?%d\n",?value,?port);?
???return?0;?
}?
??
??

函数名:?outportb?

功??能:?输出字节到硬件端口中?

用??法:?void?outportb(int?port,?char?byte);?

程序例:?

#include?<stdio.h>?
#include?<dos.h>?
int?main(void)?
{?
???int?value?=?64;?
???int?port?=?0;?
???outportb(port,?value);?
???printf("Value?%d?sent?to?port?number?%d\n",?value,?port);?
???return?0;?
}?
??
??

函数名:?outtext?

功??能:?在视区显示一个字符串?

用??法:?void?far?outtext(char?far?*textstring);?

程序例:?

#include?<graphics.h>?
#include?<stdlib.h>?
#include?<stdio.h>?
#include?<conio.h>?
int?main(void)?
{?
???/*?request?auto?detection?*/?
???int?gdriver?=?DETECT,?gmode,?errorcode;?
???int?midx,?midy;?
???/*?initialize?graphics?and?local?variables?*/?
???initgraph(&gdriver,?&gmode,?"");?
???/*?read?result?of?initialization?*/?
???errorcode?=?graphresult();?
???if?(errorcode?!=?grOk)??/*?an?error?occurred?*/?
???{?
??????printf("Graphics?error:?%s\n",?grapherrormsg(errorcode));?
??????printf("Press?any?key?to?halt:");?
??????getch();?
??????exit(1);?/*?terminate?with?an?error?code?*/?
???}?
???midx?=?getmaxx()?/?2;?
???midy?=?getmaxy()?/?2;?
???/*?move?the?C.P.?to?the?center?of?the?screen?*/?
???moveto(midx,?midy);?
???/*?output?text?starting?at?the?C.P.?*/?
???outtext("This?");?
???outtext("is?");?
???outtext("a?");?
???outtext("test.");?
???/*?clean?up?*/?
???getch();?
???closegraph();?
???return?0;?
}?
??
??

函数名:?outtextxy?

功??能:?在指定位置显示一字符串?

用??法:?void?far?outtextxy(int?x,?int?y,?char?*textstring);?

程序例:?

#include?<graphics.h>?
#include?<stdlib.h>?
#include?<stdio.h>?
#include?<conio.h>?
int?main(void)?
{?
???/*?request?auto?detection?*/?
???int?gdriver?=?DETECT,?gmode,?errorcode;?
???int?midx,?midy;?
???/*?initialize?graphics?and?local?variables?*/?
???initgraph(?&gdriver,?&gmode,?"");?
???/*?read?result?of?initialization?*/?
???errorcode?=?graphresult();?
???if?(errorcode?!=?grOk)??/*?an?error?occurred?*/?
???{?
??????printf("Graphics?error:?%s\n",?grapherrormsg(errorcode));?
??????printf("Press?any?key?to?halt:");?
??????getch();?
??????exit(1);?/*?terminate?with?an?error?code?*/?
???}?
???midx?=?getmaxx()?/?2;?
???midy?=?getmaxy()?/?2;?
???/*?output?text?at?the?center?of?the?screen*/?
???/*?Note:?the?C.P.?doesn‘t?get?changed.*/?
???outtextxy(midx,?midy,?"This?is?a?test.");?
???/*?clean?up?*/?
???getch();?
???closegraph();?
???return?0;?
}?
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