站长资讯网函数名: gcvt
功 能: 把浮点数转换成字符串
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);
}
函数名: geninterrupt
功 能: 产生一个软中断
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 */
}
函数名: getarccoords
功 能: 取得最后一次调用arc的坐标
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;
}
函数名: getaspectratio
功 能: 返回当前图形模式的纵横比
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;
}
函数名: getbkcolor
功 能: 返回当前背景颜色
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;
}
函数名: getc
功 能: 从流中取字符
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;
}
函数名: getcbrk
功 能: 获取Control_break设置
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;
}
函数名: getch
功 能: 从控制台无回显地取一个字符
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;
}
函数名: getchar
功 能: 从stdin流中读字符
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;
}
函数名: getche
功 能: 从控制台取字符(带回显)
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;
}
函数名: getcolor
功 能: 返回当前画线颜色
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;
}
函数名: getcurdir
功 能: 取指定驱动器的当前目录
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;
}
函数名: getcwd
功 能: 取当前工作目录
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;
}
函数名: 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;
}
函数名: getdefaultpalette
功 能: 返回调色板定义结构
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;
}
函数名: getdisk
功 能: 取当前磁盘驱动器号
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;
}
函数名: getdrivername
功 能: 返回指向包含当前图形驱动程序名字的字符串指针
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;
}
函数名: getdta
功 能: 取磁盘传输地址
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;
}
函数名: getenv
功 能: 从环境中取字符串
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;
}
函数名: 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;
}
函数名: getfillpattern
功 能: 将用户定义的填充模式拷贝到内存中
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;
}
函数名: getfillsettings
功 能: 取得有关当前填充模式和填充颜色的信息
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;
}
函数名: getftime
功 能: 取文件日期和时间
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.$$$”,
“wt”)) == NULL)
{
fprintf(stderr,
“Cannot open output file.n”);
return 1;
}
getftime(fileno(stream), &ft);
printf(“File time: %u:%u:%un”,
ft.ft_hour, ft.ft_min,
ft.ft_tsec * 2);
printf(“File date: %u/%u/%un”,
ft.ft_month, ft.ft_day,
ft.ft_year+1980);
fclose(stream);
return 0;
}
函数名: getgraphmode
功 能: 返回当前图形模式
用 法: int far getgraphmode(void);
程序例:
#include <graphics.h>
#include <stdlib.h>
#include <stdio.h>
#include <conio.h>
int main(void)
{
/* request auto detection */
int gdriver = DETECT, gmode, errorcode;
int midx, midy, mode;
char numname[80], modename[80];
/* initialize graphics and local variables */
initgraph(&gdriver, &gmode, “”);
/* read result of initialization */
errorcode = graphresult();
/* an error occurred */
if (errorcode != grOk)
{
printf(“Graphics error: %sn”,
grapherrormsg(errorcode));
printf(“Press any key to halt:”);
getch();
/* terminate with an error code */
exit(1);
}
midx = getmaxx() / 2;
midy = getmaxy() / 2;
/* get mode number and name strings */
mode = getgraphmode();
sprintf(numname,
“%d is the current mode number.”,
mode);
sprintf(modename,
“%s is the current graphics mode”,
getmodename(mode));
/* display the information */
settextjustify(CENTER_TEXT, CENTER_TEXT);
outtextxy(midx, midy, numname);
outtextxy(midx, midy+2*textheight(“W”),
modename);
/* clean up */
getch();
closegraph();
return 0;
}
函数名: getftime
功 能: 取文件日期和时间
用 法: int getftime(int handle, struct ftime *ftimep);
程序例:
#include <stdio.h>
#include <io.h>
int main(void)
{
FILE *stream;
struct ftime ft;
if ((stream = fopen(“TEST.$$$”,
“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;
}
函数名: getgraphmode
功 能: 返回当前图形模式
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;
}
函数名: getimage
功 能: 将指定区域的一个位图存到主存中
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;
}
}
函数名: getlinesettings
功 能: 取当前线型、模式和宽度
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;
}
函数名: getmaxcolor
功 能: 返回可以传给函数setcolor的最大颜色值
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;
}
函数名: getmaxx
功 能: 返回屏幕的最大x坐标
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;
}
函数名: getmaxy
功 能: 返回屏幕的最大y坐标
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;
}
函数名: getmodename
功 能: 返回含有指定图形模式名的字符串指针
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;
}
函数名: getmoderange
功 能: 取给定图形驱动程序的模式范围
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;
}
函数名: getpalette
功 能: 返回有关当前调色板的信息
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;
}
函数名: getpass
功 能: 读一个口令
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;
}
函数名: getpixel
功 能: 取得指定像素的颜色
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; ; ; ; ; ; ; ; ;
函数名: gets
功 能: 从流中取一字符串
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;
}
函数名: gettext
功 能: 将文本方式屏幕上的文本拷贝到存储区
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;
}
函数名: gettextinfo
功 能: 取得文本模式的显示信息
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;
}
函数名: gettextsettings
功 能: 返回有关当前图形文本字体的信息
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;
}
函数名: gettime
功 能: 取得系统时间
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;
}
函数名: getvect
功 能: 取得中断向量入口
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 */
}
函数名: getverify
功 能: 返回DOS校验标志状态
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;
}
函数名: getviewsetting
功 能: 返回有关当前视区的信息
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;
}
函数名: getw
功 能: 从流中取一整数
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;
}
函数名: getx
功 能: 返回当前图形位置的x坐标
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;
}
函数名: gety
功 能: 返回当前图形位置的y坐标
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;
}
函数名: gmtime
功 能: 把日期和时间转换为格林尼治标准时间(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;
}
函数名: gotoxy
功 能: 在文本窗口中设置光标
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;
}
函数名: gotoxy
功 能: 在文本窗口中设置光标
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;
}
函数名: graphdefaults
功 能: 将所有图形设置复位为它们的缺省值
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;
}
函数名: grapherrormsg
功 能: 返回一个错误信息串的指针
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;
}
函数名: graphresult
功 能: 返回最后一次不成功的图形操作的错误代码
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;
}
函数名: _graphfreemem
功 能: 用户可修改的图形存储区释放函数
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);
}
函数名: _graphgetmem
功 能: 用户可修改的图形存储区分配函数
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);
}
