fs.htm

turbo c

<P>&nbsp;&nbsp; /* Add one to the minutes struct element and then call
settime&nbsp; */
<BR>&nbsp;&nbsp; t.ti_min++;
<BR>&nbsp;&nbsp; settime(&amp;t);

<P>&nbsp;&nbsp; return 0;
<BR>}
<BR>&nbsp;
<BR>&nbsp;

<P>函数名: setusercharsize
<BR>功&nbsp; 能: 为矢量字体改变字符宽度和高度
<BR>用&nbsp; 法: void far setusercharsize(int multx, int dirx, int multy,
int diry);
<BR>程序例:

<P>#include &lt;graphics.h>
<BR>#include &lt;stdlib.h>
<BR>#include &lt;stdio.h>
<BR>#include &lt;conio.h>

<P>int main(void)
<BR>{
<BR>&nbsp;&nbsp; /* request autodetection */
<BR>&nbsp;&nbsp; int gdriver = DETECT, gmode, errorcode;

<P>&nbsp;&nbsp; /* initialize graphics and local variables */
<BR>&nbsp;&nbsp; initgraph(&amp;gdriver, &amp;gmode, "");

<P>&nbsp;&nbsp; /* read result of initialization */
<BR>&nbsp;&nbsp; errorcode = graphresult();
<BR>&nbsp;&nbsp; if (errorcode != grOk)&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; /*
an error occurred */
<BR>&nbsp;&nbsp; {
<BR>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; printf("Graphics error: %s\n", grapherrormsg(errorcode));
<BR>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; printf("Press any key to halt:");
<BR>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; getch();
<BR>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; exit(1);&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;
/* terminate with an error code */
<BR>&nbsp;&nbsp; }

<P>&nbsp;&nbsp; /* select a text style */
<BR>&nbsp;&nbsp; settextstyle(TRIPLEX_FONT, HORIZ_DIR, 4);

<P>&nbsp;&nbsp; /* move to the text starting position */
<BR>&nbsp;&nbsp; moveto(0, getmaxy() / 2);

<P>&nbsp;&nbsp; /* output some normal text */
<BR>&nbsp;&nbsp; outtext("Norm ");

<P>&nbsp;&nbsp; /* make the text 1/3 the normal width */
<BR>&nbsp;&nbsp; setusercharsize(1, 3, 1, 1);
<BR>&nbsp;&nbsp; outtext("Short ");

<P>&nbsp;&nbsp; /* make the text 3 times normal width */
<BR>&nbsp;&nbsp; setusercharsize(3, 1, 1, 1);
<BR>&nbsp;&nbsp; outtext("Wide");

<P>&nbsp;&nbsp; /* clean up */
<BR>&nbsp;&nbsp; getch();
<BR>&nbsp;&nbsp; closegraph();
<BR>&nbsp;&nbsp; return 0;
<BR>}
<BR>&nbsp;

<P>函数名: setvbuf
<BR>功&nbsp; 能: 把缓冲区与流相关
<BR>用&nbsp; 法: int setvbuf(FILE *stream, char *buf, int type, unsigned
size);
<BR>程序例:

<P>#include &lt;stdio.h>

<P>int main(void)
<BR>{
<BR>&nbsp;&nbsp; FILE *input, *output;
<BR>&nbsp;&nbsp; char bufr[512];

<P>&nbsp;&nbsp; input = fopen("file.in", "r+b");
<BR>&nbsp;&nbsp; output = fopen("file.out", "w");

<P>&nbsp;&nbsp; /* set up input stream for minimal disk access,
<BR>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; using our own character buffer */
<BR>&nbsp;&nbsp; if (setvbuf(input, bufr, _IOFBF, 512) != 0)
<BR>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; printf("failed to set up buffer for
input file\n");
<BR>&nbsp;&nbsp; else
<BR>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; printf("buffer set up for input file\n");

<P>&nbsp;&nbsp; /* set up output stream for line buffering using space
that
<BR>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; will be obtained through an indirect
call to malloc */
<BR>&nbsp;&nbsp; if (setvbuf(output, NULL, _IOLBF, 132) != 0)
<BR>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; printf("failed to set up buffer for
output file\n");
<BR>&nbsp;&nbsp; else
<BR>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; printf("buffer set up for output file\n");

<P>&nbsp;&nbsp; /* perform file I/O here */

<P>&nbsp;&nbsp; /* close files */
<BR>&nbsp;&nbsp; fclose(input);
<BR>&nbsp;&nbsp; fclose(output);
<BR>&nbsp;&nbsp; return 0;
<BR>}
<BR>&nbsp;
<BR>&nbsp;
<BR>&nbsp;

<P>函数名: setvect
<BR>功&nbsp; 能: 设置中断矢量入口
<BR>用&nbsp; 法: void setvect(int intr_num, void interrupt(*isr)());
<BR>程序例:

<P>/***NOTE:
<BR>&nbsp;&nbsp;&nbsp; This is an interrupt service routine.&nbsp; You
can NOT compile this
<BR>&nbsp;&nbsp;&nbsp; program with Test Stack Overflow turned on and get
an executable
<BR>&nbsp;&nbsp;&nbsp; file which will operate correctly. */

<P>#include &lt;stdio.h>
<BR>#include &lt;dos.h>
<BR>#include &lt;conio.h>

<P>#define INTR 0X1C&nbsp;&nbsp;&nbsp; /* The clock tick interrupt */

<P>void interrupt ( *oldhandler)(void);

<P>int count=0;

<P>void interrupt handler(void)
<BR>{
<BR>/* increase the global counter */
<BR>&nbsp;&nbsp; count++;

<P>/* call the old routine */
<BR>&nbsp;&nbsp; oldhandler();
<BR>}

<P>int main(void)
<BR>{
<BR>/* save the old interrupt vector */
<BR>&nbsp;&nbsp; oldhandler = getvect(INTR);

<P>/* install the new interrupt handler */
<BR>&nbsp;&nbsp; setvect(INTR, handler);

<P>/* loop until the counter exceeds 20 */
<BR>&nbsp;&nbsp; while (count &lt; 20)
<BR>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; printf("count is %d\n",count);

<P>/* reset the old interrupt handler */
<BR>&nbsp;&nbsp; setvect(INTR, oldhandler);

<P>&nbsp;&nbsp; return 0;
<BR>}
<BR>&nbsp;
<BR>&nbsp;

<P>函数名: setverify
<BR>功&nbsp; 能: 设置验证状态
<BR>用&nbsp; 法: void setverify(int value);
<BR>程序例:

<P>#include &lt;stdio.h>
<BR>#include &lt;conio.h>
<BR>#include &lt;dos.h>

<P>int main(void)
<BR>{
<BR>&nbsp;&nbsp; int verify_flag;

<P>&nbsp;&nbsp; printf("Enter 0 to set verify flag off\n");
<BR>&nbsp;&nbsp; printf("Enter 1 to set verify flag on\n");

<P>&nbsp;&nbsp; verify_flag = getch() - 0;

<P>&nbsp;&nbsp; setverify(verify_flag);

<P>&nbsp;&nbsp; if (getverify())
<BR>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; printf("DOS verify flag is on\n");
<BR>&nbsp;&nbsp; else
<BR>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; printf("DOS verify flag is off\n");

<P>&nbsp;&nbsp; return 0;
<BR>}
<BR>&nbsp;
<BR>&nbsp;

<P>函数名: setviewport
<BR>功&nbsp; 能: 为图形输出设置当前视口
<BR>用&nbsp; 法: void far setviewport(int left, int top, int right,
<BR>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; int bottom, int clipflag);
<BR>程序例:

<P>#include &lt;graphics.h>
<BR>#include &lt;stdlib.h>
<BR>#include &lt;stdio.h>
<BR>#include &lt;conio.h>

<P>#define CLIP_ON 1&nbsp;&nbsp; /* activates clipping in viewport */

<P>int main(void)
<BR>{
<BR>&nbsp;&nbsp; /* request auto detection */
<BR>&nbsp;&nbsp; int gdriver = DETECT, gmode, errorcode;

<P>&nbsp;&nbsp; /* initialize graphics and local variables */
<BR>&nbsp;&nbsp; initgraph(&amp;gdriver, &amp;gmode, "");

<P>&nbsp;&nbsp; /* read result of initialization */
<BR>&nbsp;&nbsp; errorcode = graphresult();
<BR>&nbsp;&nbsp; if (errorcode != grOk)&nbsp; /* an error occurred */
<BR>&nbsp;&nbsp; {
<BR>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; printf("Graphics error: %s\n", grapherrormsg(errorcode));
<BR>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; printf("Press any key to halt:");
<BR>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; getch();
<BR>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; exit(1); /* terminate with an error
code */
<BR>&nbsp;&nbsp; }

<P>&nbsp;&nbsp; setcolor(getmaxcolor());

<P>&nbsp;&nbsp; /* message in default full-screen viewport */
<BR>&nbsp;&nbsp; outtextxy(0, 0, "* &lt;-- (0, 0) in default viewport");

<P>&nbsp;&nbsp; /* create a smaller viewport */
<BR>&nbsp;&nbsp; setviewport(50, 50, getmaxx()-50, getmaxy()-50, CLIP_ON);

<P>&nbsp;&nbsp; /* display some text */
<BR>&nbsp;&nbsp; outtextxy(0, 0, "* &lt;-- (0, 0) in smaller viewport");

<P>&nbsp;&nbsp; /* clean up */
<BR>&nbsp;&nbsp; getch();
<BR>&nbsp;&nbsp; closegraph();
<BR>&nbsp;&nbsp; return 0;
<BR>}
<BR>&nbsp;
<BR>&nbsp;

<P>函数名: setvisualpage
<BR>功&nbsp; 能: 设置可见图形页号
<BR>用&nbsp; 法: void far setvisualpage(int pagenum);
<BR>程序例:

<P>#include &lt;graphics.h>
<BR>#include &lt;stdlib.h>
<BR>#include &lt;stdio.h>
<BR>#include &lt;conio.h>

<P>int main(void)
<BR>{
<BR>&nbsp;&nbsp; /* select a driver and mode that supports */
<BR>&nbsp;&nbsp; /* multiple pages.&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;
*/
<BR>&nbsp;&nbsp; int gdriver = EGA, gmode = EGAHI, errorcode;
<BR>&nbsp;&nbsp; int x, y, ht;

<P>&nbsp;&nbsp; /* initialize graphics and local variables */
<BR>&nbsp;&nbsp; initgraph(&amp;gdriver, &amp;gmode, "");

<P>&nbsp;&nbsp; /* read result of initialization */
<BR>&nbsp;&nbsp; errorcode = graphresult();
<BR>&nbsp;&nbsp; if (errorcode != grOk)&nbsp; /* an error occurred */
<BR>&nbsp;&nbsp; {
<BR>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; printf("Graphics error: %s\n", grapherrormsg(errorcode));
<BR>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; printf("Press any key to halt:");
<BR>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; getch();
<BR>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; exit(1); /* terminate with an error
code */
<BR>&nbsp;&nbsp; }

<P>&nbsp;&nbsp; x = getmaxx() / 2;
<BR>&nbsp;&nbsp; y = getmaxy() / 2;
<BR>&nbsp;&nbsp; ht = textheight("W");

<P>&nbsp;&nbsp; /*&nbsp; select the off screen page for drawing */
<BR>&nbsp;&nbsp; setactivepage(1);

<P>&nbsp;&nbsp; /* draw a line on page #1 */
<BR>&nbsp;&nbsp; line(0, 0, getmaxx(), getmaxy());

<P>&nbsp;&nbsp; /* output a message on page #1 */
<BR>&nbsp;&nbsp; settextjustify(CENTER_TEXT, CENTER_TEXT);
<BR>&nbsp;&nbsp; outtextxy(x, y, "This is page #1:");
<BR>&nbsp;&nbsp; outtextxy(x, y+ht, "Press any key to halt:");

<P>&nbsp;&nbsp; /* select drawing to page #0 */
<BR>&nbsp;&nbsp; setactivepage(0);

<P>&nbsp;&nbsp; /* output a message&nbsp; on page #0 */
<BR>&nbsp;&nbsp; outtextxy(x, y, "This is page #0.");
<BR>&nbsp;&nbsp; outtextxy(x, y+ht, "Press any key to view page #1:");
<BR>&nbsp;&nbsp; getch();

<P>&nbsp;&nbsp; /* select page #1 as the visible page */
<BR>&nbsp;&nbsp; setvisualpage(1);

<P>&nbsp;&nbsp; /* clean up */
<BR>&nbsp;&nbsp; getch();
<BR>&nbsp;&nbsp; closegraph();
<BR>&nbsp;&nbsp; return 0;
<BR>}
<BR>&nbsp;
<BR>&nbsp;

<P>函数名: setwritemode
<BR>功&nbsp; 能: 设置图形方式下画线的输出模式
<BR>用&nbsp; 法: void far setwritemode(int mode);
<BR>程序例:

<P>#include &lt;graphics.h>
<BR>#include &lt;stdlib.h>
<BR>#include &lt;stdio.h>
<BR>#include &lt;conio.h>

<P>int main()
<BR>{
<BR>&nbsp;&nbsp; /* request auto detection */
<BR>&nbsp;&nbsp; int gdriver = DETECT, gmode, errorcode;
<BR>&nbsp;&nbsp; int xmax, ymax;

<P>&nbsp;&nbsp; /* initialize graphics and local variables */
<BR>&nbsp;&nbsp; initgraph(&amp;gdriver, &amp;gmode, "");

<P>&nbsp;&nbsp; /* read result of initialization */
<BR>&nbsp;&nbsp; errorcode = graphresult();
<BR>&nbsp;&nbsp; if (errorcode != grOk)&nbsp; /* an error occurred */
<BR>&nbsp;&nbsp; {
<BR>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; printf("Graphics error: %s\n", grapherrormsg(errorcode));
<BR>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; printf("Press any key to halt:");
<BR>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; getch();
<BR>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; exit(1); /* terminate with an error
code */
<BR>&nbsp;&nbsp; }

<P>&nbsp;&nbsp; xmax = getmaxx();
<BR>&nbsp;&nbsp; ymax = getmaxy();

<P>&nbsp;&nbsp; /* select XOR drawing mode */
<BR>&nbsp;&nbsp; setwritemode(XOR_PUT);

<P>&nbsp;&nbsp; /* draw a line */
<BR>&nbsp;&nbsp; line(0, 0, xmax, ymax);
<BR>&nbsp;&nbsp; getch();

<P>&nbsp;&nbsp; /* erase the line by drawing over it */
<BR>&nbsp;&nbsp; line(0, 0, xmax, ymax);
<BR>&nbsp;&nbsp; getch();

<P>&nbsp;&nbsp; /* select overwrite drawing mode */
<BR>&nbsp;&nbsp; setwritemode(COPY_PUT);

<P>&nbsp;&nbsp; /* draw a line */
<BR>&nbsp;&nbsp; line(0, 0, xmax, ymax);

<P>&nbsp;&nbsp; /* clean up */
<BR>&nbsp;&nbsp; getch();
<BR>&nbsp;&nbsp; closegraph();
<BR>&nbsp;&nbsp; return 0;
<BR>}
<BR>&nbsp;
<BR>&nbsp;

<P>函数名: signal
<BR>功&nbsp; 能: 设置某一信号的对应动作
<BR>用&nbsp; 法: int signal(int sig, sigfun fname);
<BR>程序例:

<P>/* This example installs a signal handler routine for SIGFPE,
<BR>&nbsp;&nbsp; catches an integer overflow condition, makes an adjustment
<BR>&nbsp;&nbsp; to AX register, and returns. This example program MAY
cause
<BR>&nbsp;&nbsp; your computer to crash, and will produce runtime errors
<BR>&nbsp;&nbsp; depending on which memory model is used.
<BR>*/

<P>#pragma inline
<BR>#include &lt;stdio.h>
<BR>#include &lt;signal.h>

<P>void Catcher(int sig, int type, int *reglist)
<BR>{
<BR>&nbsp;&nbsp; printf("Caught it!\n");
<BR>&nbsp;&nbsp; *(reglist + 8) = 3;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;
/* make return AX = 3 */
<BR>}

<P>int main(void)
<BR>{
<BR>&nbsp;&nbsp; signal(SIGFPE, Catcher);
<BR>&nbsp;&nbsp; asm&nbsp;&nbsp;&nbsp;&nbsp; mov&nbsp;&nbsp;&nbsp;&nbsp;
ax,07FFFH&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; /* AX = 32767 */
<BR>&nbsp;&nbsp; asm&nbsp;&nbsp;&nbsp;&nbsp; inc&nbsp;&nbsp;&nbsp;&nbsp;
ax&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;
/* cause overflow */
<BR>&nbsp;&nbsp; asm&nbsp;&nbsp;&nbsp;&nbsp; into&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;
/* activate handler */

<P>&nbsp;&nbsp; /* The handler set AX to 3 on return. If that hadn't happened,
<BR>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; there would have been another exception
when the next 'into'
<BR>&nbsp;&nbsp;&nbsp;&n