函數(shù)名: gcvt
功  能: 把浮點(diǎn)數(shù)轉(zhuǎn)換成字符串
用  法: char *gcvt(double value, int ndigit, char *buf);
程序例:

#include <stdlib.h>
#include <stdio.h>

int main(void)
{
   char str[25];
   double num;
   int sig = 5; /* significant digits */

   /* a regular number */
   num = 9.876;
   gcvt(num, sig, str);
   printf(“string = %sn”, str);

   /* a negative number */
   num = -123.4567;
   gcvt(num, sig, str);
   printf(“string = %sn”, str);

   /* scientific notation */
   num = 0.678e5;
   gcvt(num, sig, str);
   printf(“string = %sn”, str);

   return(0);
}
 
 
 

函數(shù)名: geninterrupt
功  能: 產(chǎn)生一個(gè)軟中斷
用  法: void geninterrupt(int intr_num);
程序例:

#include <conio.h>
#include <dos.h>

/* function prototype */
void writechar(char ch);

int main(void)
{
   clrscr();
   gotoxy(80,25);
   writechar(‘*’);
   getch();
   return 0;
}

/*
   outputs a character at the current cursor
   position using the video BIOS to avoid the
   scrolling of the screen when writing to
   location (80,25).
*/

void writechar(char ch)
{
   struct text_info ti;
   /* grab current text settings */
   gettextinfo(&ti);
   /* interrupt 0x10 sub-function 9 */
   _AH = 9;
   /* character to be output */
   _AL = ch;
   _BH = 0;                  /* video page */
   _BL = ti.attribute;  /* video attribute */
   _CX = 1;           /* repetition factor */
   geninterrupt(0x10);  /* output the char */
}
 
 

函數(shù)名: getarccoords
功  能: 取得最后一次調(diào)用arc的坐標(biāo)
用  法: void far getarccoords(struct arccoordstype far *arccoords);
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;
   struct arccoordstype arcinfo;
   int midx, midy;
   int stangle = 45, endangle = 270;
   char sstr[80], estr[80];

/* initialize graphics and local variables */
   initgraph(&gdriver, &gmode, “”);

/* read result of initialization */
   errorcode = graphresult();
/* an error occurred */
   if (errorcode != grOk)
   {
      printf(“Graphics error: %sn”,
             grapherrormsg(errorcode));
      printf(“Press any key to halt:”);
      getch();
/* terminate with an error code */
      exit(1);
   }

   midx = getmaxx() / 2;
   midy = getmaxy() / 2;

/* draw arc and get coordinates */
   setcolor(getmaxcolor());
   arc(midx, midy, stangle, endangle, 100);
   getarccoords(&arcinfo);

/* convert arc information into strings */
   sprintf(sstr, “*- (%d, %d)”,
           arcinfo.xstart, arcinfo.ystart);
   sprintf(estr, “*- (%d, %d)”,
           arcinfo.xend, arcinfo.yend);

   /* output the arc information */
   outtextxy(arcinfo.xstart,
             arcinfo.ystart, sstr);
   outtextxy(arcinfo.xend,
             arcinfo.yend, estr);

   /* clean up */
   getch();
   closegraph();
   return 0;
}
 
 
 

函數(shù)名: getaspectratio
功  能: 返回當(dāng)前圖形模式的縱橫比
用  法: void far getaspectratio(int far *xasp, int far *yasp);
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 xasp, yasp, midx, midy;

/* initialize graphics and local variables */
   initgraph(&gdriver, &gmode, “”);

/* read result of initialization */
   errorcode = graphresult();
/* an error occurred */
   if (errorcode != grOk)
   {
      printf(“Graphics error: %sn”,
             grapherrormsg(errorcode));
      printf(“Press any key to halt:”);
      getch();
/* terminate with an error code */
      exit(1);
   }

   midx = getmaxx() / 2;
   midy = getmaxy() / 2;
   setcolor(getmaxcolor());

/* get current aspect ratio settings */
   getaspectratio(&xasp, &yasp);

/* draw normal circle */
   circle(midx, midy, 100);
   getch();

/* draw wide circle */
   cleardevice();
   setaspectratio(xasp/2, yasp);
   circle(midx, midy, 100);
   getch();

/* draw narrow circle */
   cleardevice();
   setaspectratio(xasp, yasp/2);
   circle(midx, midy, 100);

/* clean up */
   getch();
   closegraph();
   return 0;
}
 
 
 

函數(shù)名: getbkcolor
功  能: 返回當(dāng)前背景顏色
用  法: int far getbkcolor(void);
程序例:

#include <graphics.h>
#include <stdlib.h>
#include <string.h>
#include <stdio.h>
#include <conio.h>

int main(void)
{
   /* request auto detection */
   int gdriver = DETECT, gmode, errorcode;
   int bkcolor, midx, midy;
   char bkname[35];

/* initialize graphics and local variables */
   initgraph(&gdriver, &gmode, “”);

/* read result of initialization */
   errorcode = graphresult();
/* an error occurred */
   if (errorcode != grOk)
   {
      printf(“Graphics error: %sn”,
             grapherrormsg(errorcode));
      printf(“Press any key to halt:”);
      getch();
/* terminate with an error code */
      exit(1);
   }

   midx = getmaxx() / 2;
   midy = getmaxy() / 2;
   setcolor(getmaxcolor());

/* for centering text on the display */
   settextjustify(CENTER_TEXT, CENTER_TEXT);

/* get the current background color */
   bkcolor = getbkcolor();

/* convert color value into a string */
   itoa(bkcolor, bkname, 10);
   strcat(bkname,
 ” is the current background color.”);

/* display a message */
   outtextxy(midx, midy, bkname);

/* clean up */
   getch();
   closegraph();
   return 0;
}
 
 
 

函數(shù)名: getc
功  能: 從流中取字符
用  法: int getc(FILE *stream);
程序例:

#include <stdio.h>

int main(void)
{
   char ch;

   printf(“Input a character:”);
/* read a character from the
   standard input stream */
   ch = getc(stdin);
   printf(“The character input was: ‘%c’n”,
          ch);
   return 0;
}
 
 
 

函數(shù)名: getcbrk
功  能: 獲取Control_break設(shè)置
用  法: int getcbrk(void);
程序例:

#include <stdio.h>
#include <dos.h>

int main(void)
{
   if (getcbrk())
      printf(“Cntrl-brk flag is onn”);
   else
      printf(“Cntrl-brk flag is offn”);

   return 0;
}
 
 

函數(shù)名: getch
功  能: 從控制臺(tái)無(wú)回顯地取一個(gè)字符
用  法: int getch(void);
程序例:

#include <stdio.h>
#include <conio.h>

int main(void)
{
   char ch;

   printf(“Input a character:”);
   ch = getche();
   printf(“nYou input a ‘%c’n”, ch);
   return 0;
}
 
 

函數(shù)名: getchar
功  能: 從stdin流中讀字符
用  法: int getchar(void);
程序例:

#include <stdio.h>

int main(void)
{
   int c;

   /* Note that getchar reads from stdin and
      is line buffered; this means it will
      not return until you press ENTER. */

   while ((c = getchar()) != ‘n’)
      printf(“%c”, c);

   return 0;
}
 
 

函數(shù)名: getche
功  能: 從控制臺(tái)取字符(帶回顯)
用  法: int getche(void);
程序例:

#include <stdio.h>
#include <conio.h>

int main(void)
{
   char ch;

   printf(“Input a character:”);
   ch = getche();
   printf(“nYou input a ‘%c’n”, ch);
   return 0;
}
 
 

函數(shù)名: getcolor
功  能: 返回當(dāng)前畫(huà)線顏色
用  法: int far getcolor(void);
程序例:

#include <graphics.h>
#include <stdlib.h>
#include <string.h>
#include <stdio.h>
#include <conio.h>

int main(void)
{
/* request auto detection */
   int gdriver = DETECT, gmode, errorcode;
   int color, midx, midy;
   char colname[35];

/* initialize graphics and local variables */
   initgraph(&gdriver, &gmode, “”);

/* read result of initialization */
   errorcode = graphresult();
/* an error occurred */
   if (errorcode != grOk)
   {
      printf(“Graphics error: %sn”,
             grapherrormsg(errorcode));
      printf(“Press any key to halt:”);
      getch();
/* terminate with an error code */
      exit(1);
   }

   midx = getmaxx() / 2;
   midy = getmaxy() / 2;
   setcolor(getmaxcolor());

/* for centering text on the display */
   settextjustify(CENTER_TEXT, CENTER_TEXT);

/* get the current drawing color */
   color = getcolor();

/* convert color value into a string */
   itoa(color, colname, 10);
   strcat(colname,
   ” is the current drawing color.”);

/* display a message */
   outtextxy(midx, midy, colname);

/* clean up */
   getch();
   closegraph();
   return 0;
}
 
 

函數(shù)名: getcurdir
功  能: 取指定驅(qū)動(dòng)器的當(dāng)前目錄
用  法: int getcurdir(int drive, char *direc);
程序例:

#include <dir.h>
#include <stdio.h>
#include <string.h>

char *current_directory(char *path)
{
   strcpy(path, “X:\”);      /* fill string with form of response: X: */
   path[0] = ‘A’ + getdisk();    /* replace X with current drive letter */
   getcurdir(0, path+3);  /* fill rest of string with current directory */
   return(path);
}

int main(void)
{
   char curdir[MAXPATH];

   current_directory(curdir);
   printf(“The current directory is %sn”, curdir);

   return 0;
}
 
 

函數(shù)名: getcwd
功  能: 取當(dāng)前工作目錄
用  法: char *getcwd(char *buf, int n);
程序例:

#include <stdio.h>
#include <dir.h>

int main(void)
{
   char buffer[MAXPATH];

   getcwd(buffer, MAXPATH);
   printf(“The current directory is: %sn”, buffer);
   return 0;
}
 
 

函數(shù)名: getdate
功  能: 取DOS日期
用  法: void getdate(struct *dateblk);
程序例:

#include <dos.h>
#include <stdio.h>

int main(void)
{
   struct date d;

   getdate(&d);
   printf(“The current year is: %dn”,
   d.da_year);
   printf(“The current day is: %dn”,
   d.da_day);
   printf(“The current month is: %dn”,
   d.da_mon);
   return 0;
}
 
 

函數(shù)名: getdefaultpalette
功  能: 返回調(diào)色板定義結(jié)構(gòu)
用  法: struct palettetype *far getdefaultpalette(void);
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 i;

/* structure for returning palette copy */
   struct palettetype far *pal=(void *) 0;

/* initialize graphics and local variables */
   initgraph(&gdriver, &gmode, “”);

/* read result of initialization */
   errorcode = graphresult();
/* an error occurred */
   if (errorcode != grOk)
   {
      printf(“Graphics error: %sn”,
             grapherrormsg(errorcode));
      printf(“Press any key to halt:”);
      getch();
/* terminate with an error code */
      exit(1);
   }

   setcolor(getmaxcolor());

/* return a pointer to the default palette */
   pal = getdefaultpalette();

   for (i=0; i<16; i++)
   {
      printf(“colors[%d] = %dn”, i,
             pal->colors[i]);
      getch();
   }

/* clean up */
   getch();
   closegraph();
   return 0;
}
 
 

函數(shù)名: getdisk
功  能: 取當(dāng)前磁盤(pán)驅(qū)動(dòng)器號(hào)
用  法: int getdisk(void);
程序例:

#include <stdio.h>
#include <dir.h>

int main(void)
{
   int disk;

   disk = getdisk() + ‘A’;
   printf(“The current drive is: %cn”,
    disk);
   return 0;
}
 
 
 

函數(shù)名: getdrivername
功  能: 返回指向包含當(dāng)前圖形驅(qū)動(dòng)程序名字的字符串指針
用  法: char *getdrivename(void);
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;

/* stores the device driver name */
   char *drivername;

/* initialize graphics and local variables */
   initgraph(&gdriver, &gmode, “”);

/* read result of initialization */
   errorcode = graphresult();
/* an error occurred */
   if (errorcode != grOk)
   {
      printf(“Graphics error: %sn”,
              grapherrormsg(errorcode));
      printf(“Press any key to halt:”);
      getch();
/* terminate with an error code */
      exit(1);
   }

   setcolor(getmaxcolor());

/* get name of the device driver in use */
   drivername = getdrivername();

/* for centering text on the screen */
   settextjustify(CENTER_TEXT, CENTER_TEXT);

/* output the name of the driver */
   outtextxy(getmaxx() / 2, getmaxy() / 2,
      drivername);

/* clean up */
   getch();
   closegraph();
   return 0;
}
 
 

函數(shù)名: getdta
功  能: 取磁盤(pán)傳輸?shù)刂?br /> 用  法: char far *getdta(void);
程序例:

#include <dos.h>
#include <stdio.h>

int main(void)
{
   char far *dta;

   dta = getdta();
   printf(“The current disk transfer
   address is: %Fpn”, dta);
   return 0;
}
 
 

函數(shù)名: getenv
功  能: 從環(huán)境中取字符串
用  法: char *getenv(char *envvar);
程序例:

#include <stdlib.h>
#include <stdio.h>
 

int main(void)
{
    char *s;

    s=getenv(“COMSPEC”);       /* get the comspec environment parameter */
    printf(“Command processor: %sn”,s);   /* display comspec parameter */

    return 0;
}
 
 
 

函數(shù)名: getfat, getfatd
功  能: 取文件分配表信息
用  法: void getfat(int drive, struct fatinfo *fatblkp);
程序例:

#include <stdio.h>
#include <dos.h>

int main(void)
{
   struct fatinfo diskinfo;
   int flag = 0;

   printf(“Please insert disk in drive An”);
   getchar();

   getfat(1, &diskinfo);
/* get drive information */

   printf(“nDrive A: is “);
   switch((unsigned char) diskinfo.fi_fatid)
   {
      case 0xFD:
 printf(“360K low densityn”);
 break;

      case 0xF9:
 printf(“1.2 Meg high densityn”);
 break;

      default:
 printf(“unformattedn”);
 flag = 1;
   }

   if (!flag)
   {
      printf(”  sectors per cluster %5dn”,
       diskinfo.fi_sclus);
      printf(”   number of clusters %5dn”,
       diskinfo.fi_nclus);
      printf(”     bytes per sector %5dn”,
       diskinfo.fi_bysec);
   }

   return 0;
}
 
 

函數(shù)名: getfillpattern
功  能: 將用戶定義的填充模式拷貝到內(nèi)存中
用  法: void far getfillpattern(char far *upattern);
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 maxx, maxy;
   char pattern[8] = {0x00, 0x70, 0x20, 0x27, 0x25, 0x27, 0x04, 0x04};

   /* initialize graphics and local variables */
   initgraph(&gdriver, &gmode, “”);

   /* read result of initialization */
   errorcode = graphresult();
   if (errorcode != grOk)  /* an error occurred */
   {
      printf(“Graphics error: %sn”, grapherrormsg(errorcode));
      printf(“Press any key to halt:”);
      getch();
      exit(1); /* terminate with an error code */
   }

   maxx = getmaxx();
   maxy = getmaxy();
   setcolor(getmaxcolor());

   /* select a user defined fill pattern */
   setfillpattern(pattern, getmaxcolor());

   /* fill the screen with the pattern */
   bar(0, 0, maxx, maxy);

   getch();

   /* get the current user defined fill pattern */
   getfillpattern(pattern);

   /* alter the pattern we grabbed */
   pattern[4] -= 1;
   pattern[5] -= 3;
   pattern[6] += 3;
   pattern[7] -= 4;

   /* select our new pattern */
   setfillpattern(pattern, getmaxcolor());

   /* fill the screen with the new pattern */
   bar(0, 0, maxx, maxy);

   /* clean up */
   getch();
   closegraph();
   return 0;
}
 
 

函數(shù)名: getfillsettings
功  能: 取得有關(guān)當(dāng)前填充模式和填充顏色的信息
用  法: void far getfillsettings(struct fillsettingstype far *fillinfo);
程序例:

#include <graphics.h>
#include <stdlib.h>
#include <stdio.h>
#include <conio.h>

/  the names of the fill styles supported */
char *fname[] = { “EMPTY_FILL”,
                  “SOLID_FILL”,
                  “LINE_FILL”,
                  “LTSLASH_FILL”,
                  “SLASH_FILL”,
                  “BKSLASH_FILL”,
                  “LTBKSLASH_FILL”,
                  “HATCH_FILL”,
                  “XHATCH_FILL”,
                  “INTERLEAVE_FILL”,
                  “WIDE_DOT_FILL”,
                  “CLOSE_DOT_FILL”,
                  “USER_FILL”
        };

int main(void)
{
   /* request auto detection */
   int gdriver = DETECT, gmode, errorcode;
   struct fillsettingstype fillinfo;
   int midx, midy;
   char patstr[40], colstr[40];

   /* initialize graphics and local variables */
   initgraph(&gdriver, &gmode, “”);

   /* read result of initialization */
   errorcode = graphresult();
   if (errorcode != grOk)  /* an error occurred */
   {
      printf(“Graphics error: %sn”, grapherrormsg(errorcode));
      printf(“Press any key to halt:”);
      getch();
      exit(1); /* terminate with an error code */
   }

   midx = getmaxx() / 2;
   midy = getmaxy() / 2;

   /* get information about current fill pattern and color */
   getfillsettings(&fillinfo);

   /* convert fill information into strings */
   sprintf(patstr, “%s is the fill style.”, fname[fillinfo.pattern]);
   sprintf(colstr, “%d is the fill color.”, fillinfo.color);

   /* display the information */
   settextjustify(CENTER_TEXT, CENTER_TEXT);
   outtextxy(midx, midy, patstr);
   outtextxy(midx, midy+2*textheight(“W”), colstr);

   /* clean up */
   getch();
   closegraph();
   return 0;
}
 
 
 

函數(shù)名: getftime
功  能: 取文件日期和時(shí)間
用  法: int getftime(int handle, struct ftime *ftimep);
程序例:

#include <stdio.h>
#include <io.h>

int main(void)
{
   FILE *stream;
   struct ftime ft;

   if ((stream = fopen(“TEST.$$$”,
        “wt”)) == NULL)
   {
      fprintf(stderr,
             “Cannot open output file.n”);
      return 1;
   }
   getftime(fileno(stream), &ft);
   printf(“File time: %u:%u:%un”,
          ft.ft_hour, ft.ft_min,
          ft.ft_tsec * 2);
   printf(“File date: %u/%u/%un”,
   ft.ft_month, ft.ft_day,
   ft.ft_year+1980);
   fclose(stream);
   return 0;
}
 
 
 

函數(shù)名: getgraphmode
功  能: 返回當(dāng)前圖形模式
用  法: int far getgraphmode(void);
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, mode;
   char numname[80], modename[80];

/* initialize graphics and local variables */
   initgraph(&gdriver, &gmode, “”);

/* read result of initialization */
   errorcode = graphresult();
/* an error occurred */
   if (errorcode != grOk)
   {
      printf(“Graphics error: %sn”,
             grapherrormsg(errorcode));
      printf(“Press any key to halt:”);
      getch();
/* terminate with an error code */
      exit(1);
   }

   midx = getmaxx() / 2;
   midy = getmaxy() / 2;

/* get mode number and name strings */
   mode = getgraphmode();
   sprintf(numname,
           “%d is the current mode number.”,
           mode);
   sprintf(modename,
           “%s is the current graphics mode”,
           getmodename(mode));

/* display the information */
   settextjustify(CENTER_TEXT, CENTER_TEXT);
   outtextxy(midx, midy, numname);
   outtextxy(midx, midy+2*textheight(“W”),
             modename);

/* clean up */
   getch();
   closegraph();
   return 0;
}
 
 

函數(shù)名: getftime
功  能: 取文件日期和時(shí)間
用  法: int getftime(int handle, struct ftime *ftimep);
程序例:

#include <stdio.h>
#include <io.h>

int main(void)
{
   FILE *stream;
   struct ftime ft;

   if ((stream = fopen(“TEST.$$$”,
        “wt”)) == NULL)
   {
      fprintf(stderr,
             “Cannot open output file.n”);
      return 1;
   }
   getftime(fileno(stream), &ft);
   printf(“File time: %u:%u:%un”,
          ft.ft_hour, ft.ft_min,
          ft.ft_tsec * 2);
   printf(“File date: %u/%u/%un”,
   ft.ft_month, ft.ft_day,
   ft.ft_year+1980);
   fclose(stream);
   return 0;
}
 
 
 

函數(shù)名: getgraphmode
功  能: 返回當(dāng)前圖形模式
用  法: int far getgraphmode(void);
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, mode;
   char numname[80], modename[80];

/* initialize graphics and local variables */
   initgraph(&gdriver, &gmode, “”);

/* read result of initialization */
   errorcode = graphresult();
/* an error occurred */
   if (errorcode != grOk)
   {
      printf(“Graphics error: %sn”,
             grapherrormsg(errorcode));
      printf(“Press any key to halt:”);
      getch();
/* terminate with an error code */
      exit(1);
   }

   midx = getmaxx() / 2;
   midy = getmaxy() / 2;

/* get mode number and name strings */
   mode = getgraphmode();
   sprintf(numname,
           “%d is the current mode number.”,
           mode);
   sprintf(modename,
           “%s is the current graphics mode”,
           getmodename(mode));

/* display the information */
   settextjustify(CENTER_TEXT, CENTER_TEXT);
   outtextxy(midx, midy, numname);
   outtextxy(midx, midy+2*textheight(“W”),
             modename);

/* clean up */
   getch();
   closegraph();
   return 0;
}
 
 

函數(shù)名: getimage
功  能: 將指定區(qū)域的一個(gè)位圖存到主存中
用  法: void far getimage(int left, int top, int right, int bottom,
     void far *bitmap);
程序例:

#include <graphics.h>
#include <stdlib.h>
#include <stdio.h>
#include <conio.h>
#include <alloc.h>

void save_screen(void far *buf[4]);
void restore_screen(void far *buf[4]);

int maxx, maxy;

int main(void)
{
   int gdriver=DETECT, gmode, errorcode;
   void far *ptr[4];

   /* auto-detect the graphics driver and mode */
   initgraph(&gdriver, &gmode, “”);
   errorcode = graphresult(); /* check for any errors */
   if (errorcode != grOk)
   {
      printf(“Graphics error: %sn”, grapherrormsg(errorcode));
      printf(“Press any key to halt:”);
      getch();
      exit(1);
   }
   maxx = getmaxx();
   maxy = getmaxy();

   /* draw an image on the screen */
   rectangle(0, 0, maxx, maxy);
   line(0, 0, maxx, maxy);
   line(0, maxy, maxx, 0);

   save_screen(ptr);    /* save the current screen */
   getch();             /* pause screen */
   cleardevice();       /* clear screen */
   restore_screen(ptr); /* restore the screen */
   getch();             /* pause screen */

   closegraph();
   return 0;
}

void save_screen(void far *buf[4])
{
   unsigned size;
   int ystart=0, yend, yincr, block;

   yincr = (maxy+1) / 4;
   yend = yincr;
   size = imagesize(0, ystart, maxx, yend); /* get byte size of image */

   for (block=0; block<=3; block++)
   {
      if ((buf[block] = farmalloc(size)) == NULL)
      {
         closegraph();
         printf(“Error: not enough heap space in save_screen().n”);
  exit(1);
      }

      getimage(0, ystart, maxx, yend, buf[block]);
      ystart = yend + 1;
      yend += yincr + 1;
   }
}

void save_screen(void far *buf[4])
{
   unsigned size;
   int ystart=0, yend, yincr, block;

   yincr = (maxy+1) / 4;
   yend = yincr;
   size = imagesize(0, ystart, maxx, yend); /* get byte size of image */

   for (block=0; block<=3; block++)
   {
      if ((buf[block] = farmalloc(size)) == NULL)
      {
         closegraph();
         printf(“Error: not enough heap space in save_screen().n”);
  exit(1);
      }

      getimage(0, ystart, maxx, yend, buf[block]);
      ystart = yend + 1;
      yend += yincr + 1;
   }
}

void restore_screen(void far *buf[4])
{
   int ystart=0, yend, yincr, block;

   yincr = (maxy+1) / 4;
   yend = yincr;

   for (block=0; block<=3; block++)
   {
      putimage(0, ystart, buf[block], COPY_PUT);
      farfree(buf[block]);
      ystart = yend + 1;
      yend += yincr + 1;
   }
}
 
 

函數(shù)名: getlinesettings
功  能: 取當(dāng)前線型、模式和寬度
用  法: void far getlinesettings(struct linesettingstype far *lininfo):
程序例:

#include <graphics.h>
#include <stdlib.h>
#include <stdio.h>
#include <conio.h>

/* the names of the line styles supported */
char *lname[] = { “SOLID_LINE”,
                  “DOTTED_LINE”,
                  “CENTER_LINE”,
                  “DASHED_LINE”,
                  “USERBIT_LINE”
                };

int main(void)
{
   /* request auto detection */
   int gdriver = DETECT, gmode, errorcode;
   struct linesettingstype lineinfo;
   int midx, midy;
   char lstyle[80], lpattern[80], lwidth[80];

   /* initialize graphics and local variables */
   initgraph(&gdriver, &gmode, “”);

   /* read result of initialization */
   errorcode = graphresult();
   if (errorcode != grOk)  /* an error occurred */
   {
      printf(“Graphics error: %sn”, grapherrormsg(errorcode));
      printf(“Press any key to halt:”);
      getch();
      exit(1); /* terminate with an error code */
   }

   midx = getmaxx() / 2;
   midy = getmaxy() / 2;

   /* get information about current line settings */
   getlinesettings(&lineinfo);

   /* convert line information into strings */
   sprintf(lstyle, “%s is the line style.”,
           lname[lineinfo.linestyle]);
   sprintf(lpattern, “0x%X is the user-defined line pattern.”,
           lineinfo.upattern);
   sprintf(lwidth, “%d is the line thickness.”,
    lineinfo.thickness);

   /* display the information */
   settextjustify(CENTER_TEXT, CENTER_TEXT);
   outtextxy(midx, midy, lstyle);
   outtextxy(midx, midy+2*textheight(“W”), lpattern);
   outtextxy(midx, midy+4*textheight(“W”), lwidth);

   /* clean up */
   getch();
   closegraph();
   return 0;
}
 
 

函數(shù)名: getmaxcolor
功  能: 返回可以傳給函數(shù)setcolor的最大顏色值
用  法: int far getmaxcolor(void);
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;
   char colstr[80];

   /* initialize graphics and local variables
  */ initgraph(&gdriver, &gmode, “”);

   /* read result of initialization */
   errorcode = graphresult();
   if (errorcode != grOk)  /* an error occurred */
   {
      printf(“Graphics error: %sn”, grapherrormsg(errorcode));
      printf(“Press any key to halt:”);
      getch();
      exit(1); /* terminate with an error code */
   }

   midx = getmaxx() / 2;
   midy = getmaxy() / 2;

   /* grab the color info. and convert it to a string */
   sprintf(colstr, “This mode supports colors 0..%d”, getmaxcolor());

   /* display the information */
   settextjustify(CENTER_TEXT, CENTER_TEXT);
   outtextxy(midx, midy, colstr);

   /* clean up */
   getch();
   closegraph();
   return 0;
}
 
 
 

函數(shù)名: getmaxx
功  能: 返回屏幕的最大x坐標(biāo)
用  法: int far getmaxx(void);
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;
   char xrange[80], yrange[80];

   /* initialize graphics and local variables */
   initgraph(&gdriver, &gmode, “”);

   /* read result of initialization */
   errorcode = graphresult();
   if (errorcode != grOk)  /* an error occurred */
   {
      printf(“Graphics error: %sn”, grapherrormsg(errorcode));
      printf(“Press any key to halt:”);
      getch();
      exit(1); /* terminate with an error code */
   }

   midx = getmaxx() / 2;
   midy = getmaxy() / 2;

   /* convert max resolution values into strings */
   sprintf(xrange, “X values range from 0..%d”, getmaxx());
   sprintf(yrange, “Y values range from 0..%d”, getmaxy());

   /* display the information */
   settextjustify(CENTER_TEXT, CENTER_TEXT);
   outtextxy(midx, midy, xrange);
   outtextxy(midx, midy+textheight(“W”), yrange);

   /* clean up */
   getch();
   closegraph();
   return 0;
}
 
 

函數(shù)名: getmaxy
功  能: 返回屏幕的最大y坐標(biāo)
用  法: int far getmaxy(void);
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;
   char xrange[80], yrange[80];

   /* initialize graphics and local variables */
   initgraph(&gdriver, &gmode, “”);

   /* read result of initialization */
   errorcode = graphresult();
   if (errorcode != grOk)  /* an error occurred */
   {
      printf(“Graphics error: %sn”, grapherrormsg(errorcode));
      printf(“Press any key to halt:”);
      getch();
      exit(1); /* terminate with an error code */
   }

   midx = getmaxx() / 2;
   midy = getmaxy() / 2;

   /* convert max resolution values into strings */
   sprintf(xrange, “X values range from 0..%d”, getmaxx());
   sprintf(yrange, “Y values range from 0..%d”, getmaxy());

   /* display the information */
   settextjustify(CENTER_TEXT, CENTER_TEXT);
   outtextxy(midx, midy, xrange);
   outtextxy(midx, midy+textheight(“W”), yrange);

   /* clean up */
   getch();
   closegraph();
   return 0;
}
 

函數(shù)名: getmodename
功  能: 返回含有指定圖形模式名的字符串指針
用  法: char *far getmodename(int mode_name);
程序例:

#include <graphics.h>
#include <stdlib.h>
#include <stdio.h>
#include <conio.h>

int main(void)
{
   /* request autodetection */
   int gdriver = DETECT, gmode, errorcode;
   int midx, midy, mode;
   char numname[80], modename[80];

   /* initialize graphics and local variables */
   initgraph(&gdriver, &gmode, “”);

   /* read result of initialization */
   errorcode = graphresult();
   if (errorcode != grOk)  /* an error occurred */
   {
      printf(“Graphics error: %sn”, grapherrormsg(errorcode));
      printf(“Press any key to halt:”);
      getch();
      exit(1); /* terminate with an error code */
   }

   midx = getmaxx() / 2;
   midy = getmaxy() / 2;

   /* get mode number and name strings */
   mode = getgraphmode();
   sprintf(numname, “%d is the current mode number.”, mode);
   sprintf(modename, “%s is the current graphics mode.”, getmodename(mode));

   /* display the information */
   settextjustify(CENTER_TEXT, CENTER_TEXT);
   outtextxy(midx, midy, numname);
   outtextxy(midx, midy+2*textheight(“W”), modename);

   /* clean up */
   getch();
   closegraph();
   return 0;
}
 
 

函數(shù)名: getmoderange
功  能: 取給定圖形驅(qū)動(dòng)程序的模式范圍
用  法: void far getmoderange(int graphdriver, int far *lomode,
    int far *himode);
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;
   int low, high;
   char mrange[80];

   /* initialize graphics and local variables */
   initgraph(&gdriver, &gmode, “”);

   /* read result of initialization */
   errorcode = graphresult();
   if (errorcode != grOk)  /* an error occurred */
   {
      printf(“Graphics error: %sn”, grapherrormsg(errorcode));
      printf(“Press any key to halt:”);
      getch();
      exit(1); /* terminate with an error code */
   }

   midx = getmaxx() / 2;
   midy = getmaxy() / 2;

   /* get the mode range for this driver */
   getmoderange(gdriver, &low, &high);

   /* convert mode range info. into strings */
   sprintf(mrange, “This driver supports modes %d..%d”, low, high);

   /* display the information */
   settextjustify(CENTER_TEXT, CENTER_TEXT);
   outtextxy(midx, midy, mrange);

   /* clean up */
   getch();
   closegraph();
   return 0;
}
 
 

函數(shù)名: getpalette
功  能: 返回有關(guān)當(dāng)前調(diào)色板的信息
用  法: void far getpalette(struct palettetype far *palette);
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;
   struct palettetype pal;
   char psize[80], pval[20];
   int i, ht;
   int y = 10;

/* initialize graphics and local variables */
   initgraph(&gdriver, &gmode, “”);

/* read result of initialization */
   errorcode = graphresult();
/* an error occurred */
   if (errorcode != grOk)
   {
      printf(“Graphics error: %sn”,
             grapherrormsg(errorcode));
      printf(“Press any key to halt:”);
      getch();
/* terminate with an error code */
      exit(1);
   }

/* grab a copy of the palette */
   getpalette(&pal);

/* convert palette info. into strings */
   sprintf(psize, “The palette has %d
           modifiable entries.”, pal.size);

/* display the information */
   outtextxy(0, y, psize);
   if (pal.size != 0)
   {
      ht = textheight(“W”);
      y += 2*ht;
      outtextxy(0, y, “Here are the current
  values:”);
      y += 2*ht;
      for (i=0; i<pal.size; i++, y+=ht)
      {
  sprintf(pval,
   “palette[%02d]: 0x%02X”, i,
   pal.colors[i]);
  outtextxy(0, y, pval);
      }
   }

/* clean up */
   getch();
   closegraph();
   return 0;
}
 

函數(shù)名: getpass
功  能: 讀一個(gè)口令
用  法: char *getpass(char *prompt);
程序例:

#include <conio.h>

int main(void)
{
   char *password;

   password = getpass(“Input a password:”);
   cprintf(“The password is: %srn”,
    password);
   return 0;
}
 
 
 

函數(shù)名: getpixel
功  能: 取得指定像素的顏色
用  法: int far getpixel(int x, int y);
程序例:

#include <graphics.h>
#include <stdlib.h>
#include <stdio.h>
#include <conio.h>
#include <dos.h>

#define PIXEL_COUNT 1000
#define DELAY_TIME  100  /* in milliseconds */

int main(void)
{
   /* request auto detection */
   int gdriver = DETECT, gmode, errorcode;
   int i, x, y, color, maxx, maxy,
       maxcolor, seed;

/* initialize graphics and local variables */
   initgraph(&gdriver, &gmode, “”);

/* read result of initialization */
   errorcode = graphresult();
/* an error occurred */
   if (errorcode != grOk)
   {
      printf(“Graphics error: %sn”,
             grapherrormsg(errorcode));
      printf(“Press any key to halt:”);
      getch();
/* terminate with an error code */
      exit(1);
   }

   maxx = getmaxx() + 1;
   maxy = getmaxy() + 1;
   maxcolor = getmaxcolor() + 1;

   while (!kbhit())
   {
/* seed the random number generator */
      seed = random(32767);
      srand(seed);
      for (i=0; i<PIXEL_COUNT; i++)
      {
         x = random(maxx);
         y = random(maxy);
         color = random(maxcolor);
         putpixel(x, y, color);
      }

      delay(DELAY_TIME);
      srand(seed);
      for (i=0; i<PIXEL_COUNT; i++)
      {
         x = random(maxx);
         y = random(maxy);
         color = random(maxcolor);
         if (color == getpixel匇? ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ;h;(;);;; ;e;t;p;s;p;(;););;; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ;e;s;e;t; ;t;o; ;s;e;g;m;e;n;t; ;o;f; ;t;h;e; ;P;S;P; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ;i;n;e; ;i;s; ;l;o;c;a;t;e;d; ;a;t; ;o;f;f;s;e;t; ;0;x;8;1; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ;t; ;o;f; ;P;S;P; ; ; ; ; ; ; ; ;
 

函數(shù)名: gets
功  能: 從流中取一字符串
用  法: char *gets(char *string);
程序例:

#include <stdio.h>

int main(void)
{
   char string[80];

   printf(“Input a string:”);
   gets(string);
   printf(“The string input was: %sn”,
   string);
   return 0;
}
 
 

函數(shù)名: gettext
功  能: 將文本方式屏幕上的文本拷貝到存儲(chǔ)區(qū)
用  法: int gettext(int left, int top, int right, int  bottom, void *destin);
程序例:

#include <conio.h>

char buffer[4096];

int main(void)
{
   int i;
   clrscr();
   for (i = 0; i <= 20; i++)
      cprintf(“Line #%drn”, i);
   gettext(1, 1, 80, 25, buffer);
   gotoxy(1, 25);
   cprintf(“Press any key to clear screen…”);
   getch();
   clrscr();
   gotoxy(1, 25);
   cprintf(“Press any key to restore screen…”);
   getch();
   puttext(1, 1, 80, 25, buffer);
   gotoxy(1, 25);
   cprintf(“Press any key to quit…”);
   getch();
   return 0;
}
 
 

函數(shù)名: gettextinfo
功  能: 取得文本模式的顯示信息
用  法: void gettextinfo(struct text_info *inforec);
程序例:

#include <conio.h>

int main(void)
{
   struct text_info ti;
   gettextinfo(&ti);
   cprintf(“window left      %2drn”,ti.winleft);
   cprintf(“window top       %2drn”,ti.wintop);
   cprintf(“window right     %2drn”,ti.winright);
   cprintf(“window bottom    %2drn”,ti.winbottom);
   cprintf(“attribute        %2drn”,ti.attribute);
   cprintf(“normal attribute %2drn”,ti.normattr);
   cprintf(“current mode     %2drn”,ti.currmode);
   cprintf(“screen height    %2drn”,ti.screenheight);
   cprintf(“screen width     %2drn”,ti.screenwidth);
   cprintf(“current x        %2drn”,ti.curx);
   cprintf(“current y        %2drn”,ti.cury);
   return 0;
}
 
 

函數(shù)名: gettextsettings
功  能: 返回有關(guān)當(dāng)前圖形文本字體的信息
用  法: void far gettextsettings(struct textsettingstype far *textinfo);
程序例:

#include <graphics.h>
#include <stdlib.h>
#include <stdio.h>
#include <conio.h>

/* the names of the fonts supported */
char *font[] = { “DEFAULT_FONT”,
                 “TRIPLEX_FONT”,
                 “SMALL_FONT”,
                 “SANS_SERIF_FONT”,
                 “GOTHIC_FONT”
               };

/* the names of the text directions supported */
char *dir[] = { “HORIZ_DIR”, “VERT_DIR” };

/* horizontal text justifications supported */
char *hjust[] = { “LEFT_TEXT”, “CENTER_TEXT”, “RIGHT_TEXT” };

/* vertical text justifications supported */
char *vjust[] = { “BOTTOM_TEXT”, “CENTER_TEXT”, “TOP_TEXT” };

int main(void)
{
   /* request auto detection */
   int gdriver = DETECT, gmode, errorcode;
   struct textsettingstype textinfo;
   int midx, midy, ht;
   char fontstr[80], dirstr[80], sizestr[80];
   char hjuststr[80], vjuststr[80];

   /* initialize graphics and local variables */
   initgraph(&gdriver, &gmode, “”);

   /* read result of initialization */
   errorcode = graphresult();
   if (errorcode != grOk)  /* an error occurred */
   {
      printf(“Graphics error: %sn”, grapherrormsg(errorcode));
      printf(“Press any key to halt:”);
      getch();
      exit(1); /* terminate with an error code */
   }

   midx = getmaxx() / 2;
   midy = getmaxy() / 2;

   /* get information about current text settings */
   gettextsettings(&textinfo);

   /* convert text information into strings */
   sprintf(fontstr, “%s is the text style.”, font[textinfo.font]);
   sprintf(dirstr, “%s is the text direction.”, dir[textinfo.direction]);
   sprintf(sizestr, “%d is the text size.”, textinfo.charsize);
   sprintf(hjuststr, “%s is the horizontal justification.”,
           hjust[textinfo.horiz]);
   sprintf(vjuststr, “%s is the vertical justification.”,
           vjust[textinfo.vert]);

   /* display the information */
   ht = textheight(“W”);
   settextjustify(CENTER_TEXT, CENTER_TEXT);
   outtextxy(midx, midy, fontstr);
   outtextxy(midx, midy+2*ht, dirstr);
   outtextxy(midx, midy+4*ht, sizestr);
   outtextxy(midx, midy+6*ht, hjuststr);
   outtextxy(midx, midy+8*ht, vjuststr);

   /* clean up */
   getch();
   closegraph();
   return 0;
}
 

函數(shù)名: gettime
功  能: 取得系統(tǒng)時(shí)間
用  法: void gettime(struct time *timep);
程序例:

#include   <stdio.h>
#include   <dos.h>

int main(void)
{
   struct  time t;

   gettime(&t);
   printf(“The current time is: %2d:%02d:%02d.%02dn”,
          t.ti_hour, t.ti_min, t.ti_sec, t.ti_hund);
   return 0;
}
 
 
 

函數(shù)名: getvect
功  能: 取得中斷向量入口
用  法: void interrupt(*getvect(int intr_num));
程序例:

#include <stdio.h>
#include <dos.h>

void interrupt get_out(); /* interrupt prototype */

void interrupt (*oldfunc)(); /* interrupt function pointer */
int looping = 1;

int main(void)
{
  puts(“Press <Shift><Prt Sc> to terminate”);

  /* save the old interrupt */
  oldfunc  = getvect(5);

   /* install interrupt handler */
  setvect(5,get_out);

   /* do nothing */
  while (looping);

   /* restore to original interrupt routine */
   setvect(5,oldfunc);

  puts(“Success”);
  return 0;
}
void interrupt get_out()
{
  looping = 0; /* change global variable to get out of loop */
}
 
 

函數(shù)名: getverify
功  能: 返回DOS校驗(yàn)標(biāo)志狀態(tài)
用  法: int getverify(void);
程序例:

#include <stdio.h>
#include <dos.h>

int main(void)
{
   if (getverify())
      printf(“DOS verify flag is onn”);
   else
      printf(“DOS verify flag is offn”);
   return 0;
}
 

函數(shù)名: getviewsetting
功  能: 返回有關(guān)當(dāng)前視區(qū)的信息
用  法: void far getviewsettings(struct viewporttype far *viewport);
程序例:

#include <graphics.h>
#include <stdlib.h>
#include <stdio.h>
#include <conio.h>

char *clip[] = { “OFF”, “ON” };

int main(void)
{
   /* request auto detection */
   int gdriver = DETECT, gmode, errorcode;
   struct viewporttype viewinfo;
   int midx, midy, ht;
   char topstr[80], botstr[80], clipstr[80];

   /* initialize graphics and local variables */
   initgraph(&gdriver, &gmode, “”);

   /* read result of initialization */
   errorcode = graphresult();
   if (errorcode != grOk)  /* an error occurred */
   {
      printf(“Graphics error: %sn”, grapherrormsg(errorcode));
      printf(“Press any key to halt:”);
      getch();
      exit(1); /* terminate with an error code */
   }

   midx = getmaxx() / 2;
   midy = getmaxy() / 2;

   /* get information about current viewport */
   getviewsettings(&viewinfo);

   /* convert text information into strings */
   sprintf(topstr, “(%d, %d) is the upper left viewport corner.”,
           viewinfo.left, viewinfo.top);
   sprintf(botstr, “(%d, %d) is the lower right viewport corner.”,
           viewinfo.right, viewinfo.bottom);
   sprintf(clipstr, “Clipping is turned %s.”, clip[viewinfo.clip]);

   /* display the information */
   settextjustify(CENTER_TEXT, CENTER_TEXT);
   ht = textheight(“W”);
   outtextxy(midx, midy, topstr);
   outtextxy(midx, midy+2*ht, botstr);
   outtextxy(midx, midy+4*ht, clipstr);

   /* clean up */
   getch();
   closegraph();
   return 0;
}
 
 

函數(shù)名: getw
功  能: 從流中取一整數(shù)
用  法: int getw(FILE *strem);
程序例:

#include <stdio.h>
#include <stdlib.h>

#define FNAME “test.$$$”

int main(void)
{
   FILE *fp;
   int word;

   /* place the word in a file */
   fp = fopen(FNAME, “wb”);
   if (fp == NULL)
   {
      printf(“Error opening file %sn”, FNAME);
      exit(1);
   }

   word = 94;
   putw(word,fp);
   if (ferror(fp))
       printf(“Error writing to filen”);
   else
       printf(“Successful writen”);
   fclose(fp);

   /* reopen the file */
   fp = fopen(FNAME, “rb”);
   if (fp == NULL)
   {
      printf(“Error opening file %sn”, FNAME);
      exit(1);
   }

   /* extract the word */
   word = getw(fp);
   if (ferror(fp))
       printf(“Error reading filen”);
   else
       printf(“Successful read: word = %dn”, word);

   /* clean up */
   fclose(fp);
   unlink(FNAME);

   return 0;
}
 
 
 

函數(shù)名: getx
功  能: 返回當(dāng)前圖形位置的x坐標(biāo)
用  法: int far getx(void);
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;
   char msg[80];

   /* initialize graphics and local variables */
   initgraph(&gdriver, &gmode, “”);

   /* read result of initialization */
   errorcode = graphresult();
   if (errorcode != grOk)  /* an error occurred */
   {
      printf(“Graphics error: %sn”, grapherrormsg(errorcode));
      printf(“Press any key to halt:”);
      getch();
      exit(1); /* terminate with an error code */
   }

   /* move to the screen center point */
   moveto(getmaxx() / 2, getmaxy() / 2);

   /* create a message string */
   sprintf(msg, “<-(%d, %d) is the here.”, getx(), gety());

   /* display the message */
   outtext(msg);

   /* clean up */
   getch();
   closegraph();
   return 0;
}
 
 

函數(shù)名: gety
功  能: 返回當(dāng)前圖形位置的y坐標(biāo)
用  法: int far gety(void);
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;
   char msg[80];

   /* initialize graphics and local variables */
   initgraph(&gdriver, &gmode, “”);

   /* read result of initialization */
   errorcode = graphresult();
   if (errorcode != grOk)  /* an error occurred */
   {
      printf(“Graphics error: %sn”, grapherrormsg(errorcode));
      printf(“Press any key to halt:”);
      getch();
      exit(1); /* terminate with an error code */
   }

   /* move to the screen center point */
   moveto(getmaxx() / 2, getmaxy() / 2);

   /* create a message string */
   sprintf(msg, “<-(%d, %d) is the here.”, getx(), gety());

   /* display the message */
   outtext(msg);

   /* clean up */
   getch();
   closegraph();
   return 0;
}
 
 

函數(shù)名: gmtime
功  能: 把日期和時(shí)間轉(zhuǎn)換為格林尼治標(biāo)準(zhǔn)時(shí)間(GMT)
用  法: struct tm *gmtime(long *clock);
程序例:

#include <stdio.h>
#include <stdlib.h>
#include <time.h>
#include <dos.h>

/* Pacific Standard Time & Daylight Savings */
char *tzstr = “TZ=PST8PDT”;

int main(void)
{
   time_t t;
   struct tm *gmt, *area;

   putenv(tzstr);
   tzset();

   t = time(NULL);
   area = localtime(&t);
   printf(“Local time is: %s”, asctime(area));
   gmt = gmtime(&t);
   printf(“GMT is:        %s”, asctime(gmt));
   return 0;
}
 
 

函數(shù)名: gotoxy
功  能: 在文本窗口中設(shè)置光標(biāo)
用  法: void gotoxy(int x, int y);
程序例:

#include <conio.h>

int main(void)
{
   clrscr();
   gotoxy(35, 12);
   cprintf(“Hello world”);
   getch();
   return 0;
}
 
 

函數(shù)名: gotoxy
功  能: 在文本窗口中設(shè)置光標(biāo)
用  法: void gotoxy(int x, int y);
程序例:

#include <conio.h>

int main(void)
{
   clrscr();
   gotoxy(35, 12);
   cprintf(“Hello world”);
   getch();
   return 0;
}
 
 

函數(shù)名: graphdefaults
功  能: 將所有圖形設(shè)置復(fù)位為它們的缺省值
用  法: void far graphdefaults(void);
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 maxx, maxy;

   /* initialize graphics and local variables */
   initgraph(&gdriver, &gmode, “c:\bor\Borland\bgi”);

   /* read result of initialization */
   errorcode = graphresult();
   if (errorcode != grOk)  /* an error occurred */
   {
      printf(“Graphics error: %sn”, grapherrormsg(errorcode));
      printf(“Press any key to halt:”);
      getch();
      exit(1); /* terminate with an error code */
   }

   maxx = getmaxx();
   maxy = getmaxy();

   /* output line with non-default settings */
   setlinestyle(DOTTED_LINE, 0, 3);
   line(0, 0, maxx, maxy);
   outtextxy(maxx/2, maxy/3, “Before default values are restored.”);
   getch();

   /* restore default values for everything */
   graphdefaults();

   /* clear the screen */
   cleardevice();

   /* output line with default settings */
   line(0, 0, maxx, maxy);
   outtextxy(maxx/2, maxy/3, “After restoring default values.”);

   /* clean up */
   getch();
   closegraph();
   return 0;
}
 
 

函數(shù)名: grapherrormsg
功  能: 返回一個(gè)錯(cuò)誤信息串的指針
用  法: char *far grapherrormsg(int errorcode);
程序例:

#include <graphics.h>
#include <stdlib.h>
#include <stdio.h>
#include <conio.h>

#define NONSENSE -50

int main(void)
{
   /* FORCE AN ERROR TO OCCUR */
   int gdriver = NONSENSE, gmode, errorcode;

   /* initialize graphics mode */
   initgraph(&gdriver, &gmode, “”);

   /* read result of initialization */
   errorcode = graphresult();

   /* if an error occurred, then output a */
   /* descriptive error message.          */
   if (errorcode != grOk)
   {
      printf(“Graphics error: %sn”, grapherrormsg(errorcode));
      printf(“Press any key to halt:”);
      getch();
      exit(1); /* terminate with an error code */
   }

   /* draw a line */
   line(0, 0, getmaxx(), getmaxy());

   /* clean up */
   getch();
   closegraph();
   return 0;
}
 
 

函數(shù)名: graphresult
功  能: 返回最后一次不成功的圖形操作的錯(cuò)誤代碼
用  法: int far graphresult(void);
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;

   /* initialize graphics and local variables */
   initgraph(&gdriver, &gmode, “”);

   /* read result of initialization */
   errorcode = graphresult();

   if (errorcode != grOk)  /* an error occurred */
   {
      printf(“Graphics error: %sn”, grapherrormsg(errorcode));
      printf(“Press any key to halt:”);
      getch();
      exit(1); /* terminate with an error code */
   }

   /* draw a line */
   line(0, 0, getmaxx(), getmaxy());

   /* clean up */
   getch();
   closegraph();
   return 0;
}
 

函數(shù)名: _graphfreemem
功  能: 用戶可修改的圖形存儲(chǔ)區(qū)釋放函數(shù)
用  法: void far _graphfreemem(void far *ptr, unsigned size);
程序例:

#include <graphics.h>
#include <stdlib.h>
#include <stdio.h>
#include <conio.h>
#include <alloc.h>

int main(void)
{
       /* request auto detection */
       int gdriver = DETECT, gmode, errorcode;
       int midx, midy;

       /* clear the text screen */
       clrscr();
       printf(“Press any key to initialize graphics mode:”);
       getch();
       clrscr();

       /* initialize graphics and local variables */
   initgraph(&gdriver, &gmode, “”);

       /* read result of initialization */
       errorcode = graphresult();
       if (errorcode != grOk)  /* an error occurred */
       {
          printf(“Graphics error: %sn”, grapherrormsg(errorcode));
          printf(“Press any key to halt:”);
          getch();
          exit(1); /* terminate with an error code */
       }

       midx = getmaxx() / 2;
       midy = getmaxy() / 2;

       /* display a message */
       settextjustify(CENTER_TEXT, CENTER_TEXT);
       outtextxy(midx, midy, “Press any key to exit graphics mode:”);

       /* clean up */
       getch();
       closegraph();
       return 0;
}

/* called by the graphics kernel to allocate memory */
void far * far _graphgetmem(unsigned size)
{
       printf(“_graphgetmem called to allocate %d bytes.n”, size);
       printf(“hit any key:”);
       getch();
       printf(“n”);

       /* allocate memory from far heap */
       return farmalloc(size);
}

/* called by the graphics kernel to free memory */
void far _graphfreemem(void far *ptr, unsigned size)
{
       printf(“_graphfreemem called to free %d bytes.n”, size);
       printf(“hit any key:”);
       getch();
       printf(“n”);

      /* free ptr from far heap */
      farfree(ptr);
}
 

函數(shù)名: _graphgetmem
功  能: 用戶可修改的圖形存儲(chǔ)區(qū)分配函數(shù)
用  法: void far *far _graphgetmem(unsigned size);
程序例:

#include <graphics.h>
#include <stdlib.h>
#include <stdio.h>
#include <conio.h>
#include <alloc.h>

int main(void)
{
   /* request autodetection */
   int gdriver = DETECT, gmode, errorcode;
   int midx, midy;

   /* clear the text screen */
   clrscr();
   printf(“Press any key to initialize graphics mode:”);
   getch();
   clrscr();

   /* initialize graphics and local variables */
   initgraph(&gdriver, &gmode, “”);

   /* read result of initialization */
   errorcode = graphresult();
   if (errorcode != grOk)      /* an error occurred */
   {
      printf(“Graphics error: %sn”, grapherrormsg(errorcode));
      printf(“Press any key to halt:”);
      getch();
      exit(1);                 /* terminate with an error code */
   }

   midx = getmaxx() / 2;
   midy = getmaxy() / 2;

   /* display a message */
   settextjustify(CENTER_TEXT, CENTER_TEXT);
   outtextxy(midx, midy, “Press any key to exit graphics mode:”);

   /* clean up */
   getch();
   closegraph();
   return 0;
}

/* called by the graphics kernel to allocate memory */
void far * far _graphgetmem(unsigned size)
{
   printf(“_graphgetmem called to allocate %d bytes.n”, size);
   printf(“hit any key:”);
   getch();
   printf(“n”);

   /* allocate memory from far heap */
   return farmalloc(size);
}

/* called by the graphics kernel to free memory */
void far _graphfreemem(void far *ptr, unsigned size)
{
   printf(“_graphfreemem called to free %d bytes.n”, size);
   printf(“hit any key:”);
   getch();
   printf(“n”);

   /* free ptr from far heap */
   farfree(ptr);
}