C语言库函数(I类字母)
函数名: imagesize
功 能: 返回保存位图像所需的字节数
用 法: unsigned far imagesize(int left, int top, int right, int bottom);
程序例:
#include <graphics.h>
#include <stdlib.h>
#include <stdio.h>
#include <conio.h>
#define ARROW_SIZE 10
void draw_arrow(int x, int y);
int main(void)
{
/* request autodetection */
int gdriver = DETECT, gmode, errorcode;
void *arrow;
int x, y, maxx;
unsigned int size;
/* initialize graphics and local variables */
initgraph(&gdriver, &gmode, "");
/* read result of initialization */
errorcode = graphresult();
if (errorcode != grOk) /* an error occurred */
{
printf("Graphics error: %s\n", grapherrormsg(errorcode));
printf("Press any key to halt:");
getch();
exit(1); /* terminate with an error code */
}
maxx = getmaxx();
x = 0;
y = getmaxy() / 2;
/* draw the image to be grabbed */
draw_arrow(x, y);
/* calculate the size of the image */
size = imagesize(x, y-ARROW_SIZE, x+(4*ARROW_SIZE), y+ARROW_SIZE);
/* allocate memory to hold the image */
arrow = malloc(size);
/* grab the image */
getimage(x, y-ARROW_SIZE, x+(4*ARROW_SIZE), y+ARROW_SIZE, arrow);
/* repeat until a key is pressed */
while (!kbhit())
{
/* erase old image */
putimage(x, y-ARROW_SIZE, arrow, XOR_PUT);
x += ARROW_SIZE;
if (x >= maxx)
x = 0;
/* plot new image */
putimage(x, y-ARROW_SIZE, arrow, XOR_PUT);
}
/* clean up */
free(arrow);
closegraph();
return 0;
}
void draw_arrow(int x, int y)
{
/* draw an arrow on the screen */
moveto(x, y);
linerel(4*ARROW_SIZE, 0);
linerel(-2*ARROW_SIZE, -1*ARROW_SIZE);
linerel(0, 2*ARROW_SIZE);
linerel(2*ARROW_SIZE, -1*ARROW_SIZE);
}
函数名: initgraph
功 能: 初始化图形系统
用 法: void far initgraph(int far *graphdriver, int far *graphmode,
char far *pathtodriver);
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 mode */
initgraph(&gdriver, &gmode, "");
/* read result of initialization */
errorcode = graphresult();
if (errorcode != grOk) /* an error occurred */
{
printf("Graphics error: %s\n", grapherrormsg(errorcode));
printf("Press any key to halt:");
getch();
exit(1); /* return with error code */
}
/* draw a line */
line(0, 0, getmaxx(), getmaxy());
/* clean up */
getch();
closegraph();
return 0;
}
函数名: inport
功 能: 从硬件端口中输入
用 法: int inp(int protid);
程序例:
#include <stdio.h>
#include <dos.h>
int main(void)
{
int result;
int port = 0; /* serial port 0 */
result = inport(port);
printf("Word read from port %d = 0x%X\n", port, result);
return 0;
}
函数名: insline
功 能: 在文本窗口中插入一个空行
用 法: void insline(void);
程序例:
#include <conio.h>
int main(void)
{
clrscr();
cprintf("INSLINE inserts an empty line in the text window\r\n");
cprintf("at the cursor position using the current text\r\n");
cprintf("background color. All lines below the empty one\r\n");
cprintf("move down one line and the bottom line scrolls\r\n");
cprintf("off the bottom of the window.\r\n");
cprintf("\r\nPress any key to continue:");
gotoxy(1, 3);
getch();
insline();
getch();
return 0;
}
函数名: installuserdriver
功 能: 安装设备驱动程序到BGI设备驱动程序表中
用 法: int far installuserdriver(char far *name, int (*detect)(void));
程序例:
#include <graphics.h>
#include <stdlib.h>
#include <stdio.h>
#include <conio.h>
/* function prototypes */
int huge detectEGA(void);
void checkerrors(void);
int main(void)
{
int gdriver, gmode;
/* install a user written device driver */
gdriver = installuserdriver("EGA", detectEGA);
/* must force use of detection routine */
gdriver = DETECT;
/* check for any installation errors */
checkerrors();
/* initialize graphics and local variables */
initgraph(&gdriver, &gmode, "");
/* check for any initialization errors */
checkerrors();
/* draw a line */
line(0, 0, getmaxx(), getmaxy());
/* clean up */
getch();
closegraph();
return 0;
}
/* detects EGA or VGA cards */
int huge detectEGA(void)
{
int driver, mode, sugmode = 0;
detectgraph(&driver, &mode);
if ((driver == EGA) (driver == VGA))
/* return suggested video mode number */
return sugmode;
else
/* return an error code */
return grError;
}
/* check for and report any graphics errors */
void checkerrors(void)
{
int errorcode;
/* read result of last graphics operation */
errorcode = graphresult();
if (errorcode != grOk)
{
printf("Graphics error: %s\n", grapherrormsg(errorcode));
printf("Press any key to halt:");
getch();
exit(1);
}
}
函数名: installuserfont
功 能: 安装未嵌入BGI系统的字体文件(CHR)
用 法: int far installuserfont(char far *name);
程序例:
#include <graphics.h>
#include <stdlib.h>
#include <stdio.h>
#include <conio.h>
/* function prototype */
void checkerrors(void);
int main(void)
{
/* request auto detection */
int gdriver = DETECT, gmode;
int userfont;
int midx, midy;
/* initialize graphics and local variables */
initgraph(&gdriver, &gmode, "");
midx = getmaxx() / 2;
midy = getmaxy() / 2;
/* check for any initialization errors */
checkerrors();
/* install a user defined font file */
userfont = installuserfont("USER.CHR");
/* check for any installation errors */
checkerrors();
/* select the user font */
settextstyle(userfont, HORIZ_DIR, 4);
/* output some text */
outtextxy(midx, midy, "Testing!");
/* clean up */
getch();
closegraph();
return 0;
}
/* check for and report any graphics errors */
void checkerrors(void)
{
int errorcode;
/* read result of last graphics operation */
errorcode = graphresult();
if (errorcode != grOk)
{
printf("Graphics error: %s\n", grapherrormsg(errorcode));
printf("Press any key to halt:");
getch();
exit(1);
}
}
函数名: int86
功 能: 通用8086软中断接口
用 法: int int86(int intr_num, union REGS *inregs, union REGS *outregs);
程序例:
#include <stdio.h>
#include <conio.h>
#include <dos.h>
#define VIDEO 0x10
void movetoxy(int x, int y)
{
union REGS regs;
regs.h.ah = 2; /* set cursor postion */
regs.h.dh = y;
regs.h.dl = x;
regs.h.bh = 0; /* video page 0 */
int86(VIDEO, ®s, ®s);
}
int main(void)
{
clrscr();
movetoxy(35, 10);
printf("Hello\n");
return 0;
}
函数名: int86x
功 能: 通用8086软中断接口
用 法: int int86x(int intr_num, union REGS *insegs, union REGS *outregs,
strUCt SREGS *segregs);
程序例:
#include <dos.h>
#include <process.h>
#include <stdio.h>
int main(void)
{
char filename[80];
union REGS inregs, outregs;
struct SREGS segregs;
printf("Enter filename: ");
gets(filename);
inregs.h.ah = 0x43;
inregs.h.al = 0x21;
inregs.x.dx = FP_OFF(filename);
segregs.ds = FP_SEG(filename);
int86x(0x21, &inregs, &outregs, &segregs);
printf("File attribute: %X\n", outregs.x.cx);
return 0;
}
函数名: intdos
功 能: 通用DOS接口
用 法: int intdos(union REGS *inregs, union REGS *outregs);
程序例:
#include <stdio.h>
#include <dos.h>
/* deletes file name; returns 0 on success, nonzero on failure */
int delete_file(char near *filename)
{
union REGS regs;
int ret;
regs.h.ah = 0x41; /* delete file */
regs.x.dx = (unsigned) filename;
ret = intdos(®s, ®s);
/* if carry flag is set, there was an error */
return(regs.x.cflag ? ret : 0);
}
int main(void)
{
int err;
err = delete_file("NOTEXIST.$$$");
if (!err)
printf("Able to delete NOTEXIST.$$$\n");
else
printf("Not Able to delete NOTEXIST.$$$\n");
return 0;
}
函数名: intdosx
功 能: 通用DOS中断接口
用 法: int intdosx(union REGS *inregs, union REGS *outregs,
struct SREGS *segregs);
程序例:
#include <stdio.h>
#include <dos.h>
/* deletes file name; returns 0 on success, nonzero on failure */
int delete_file(char far *filename)
{
union REGS regs; struct SREGS sregs;
int ret;
regs.h.ah = 0x41; /* delete file */
regs.x.dx = FP_OFF(filename);
sregs.ds = FP_SEG(filename);
ret = intdosx(®s, ®s, &sregs);
/* if carry flag is set, there was an error */
return(regs.x.cflag ? ret : 0);
}
int main(void)
{
int err;
err = delete_file("NOTEXIST.$$$");
if (!err)
printf("Able to delete NOTEXIST.$$$\n");
else
printf("Not Able to delete NOTEXIST.$$$\n");
return 0;
}
函数名: intr
功 能: 改变软中断接口
用 法: void intr(int intr_num, struct REGPACK *preg);
程序例:
#include <stdio.h>
#include <string.h>
#include <dir.h>
#include <dos.h>
#define CF 1 /* Carry flag */
int main(void)
{
char Directory[80];
struct REGPACK reg;
printf("Enter directory to change to: ");
gets(directory);
reg.r_ax = 0x3B << 8; /* shift 3Bh into AH */
reg.r_dx = FP_OFF(directory);
reg.r_ds = FP_SEG(directory);
intr(0x21, ®);
if (reg.r_flags & CF)
printf("Directory change failed\n");
getcwd(directory, 80);
printf("The current directory is: %s\n", directory);
return 0;
}
函数名: ioctl
功 能: 控制I/O设备
用 法: int ioctl(int handle, int cmd[,int *argdx, int argcx]);
程序例:
#include <stdio.h>
#include <dir.h>
#include <io.h>
int main(void)
{
int stat;
/* use func 8 to determine if the default drive is removable */
stat = ioctl(0, 8, 0, 0);
if (!stat)
printf("Drive %c is removable.\n", getdisk() + 'A');
else
printf("Drive %c is not removable.\n", getdisk() + 'A');
return 0;
}
函数名: isatty
功 能: 检查设备类型
用 法: int isatty(int handle);
程序例:
#include <stdio.h>
#include <io.h>
int main(void)
{
int handle;
handle = fileno(stdprn);
if (isatty(handle))
printf("Handle %d is a device type\n", handle);
else
printf("Handle %d isn't a device type\n", handle);
return 0;
}
函数名: itoa
功 能: 把一整数转换为字符串
用 法: char *itoa(int value, char *string, int radix);
程序例:
#include <stdlib.h>
#include <stdio.h>
int main(void)
{
int number = 12345;
char string[25];
itoa(number, string, 10);
printf("integer = %d string = %s\n", number, string);
return 0;
}
