c语言函数大全

墙角野猫

函数名: open
功 能: 打开一个文件用于读或写
用 法: int open(char *pathname, int access[, int permiss]);
程序例:
#include
#include
#include
#include
int main(void)
{
int handle;
char msg[] = "Hello world";
if ((handle = open("TEST.$$$", O_CREAT | O_TEXT)) == -1)
{
perror("Error:");
return 1;
}
write(handle, msg, strlen(msg));
close(handle);
return 0;
}

墙角野猫

函数名: outport
功 能: 输出整数到硬件端口中
用 法: void outport(int port, int value);
程序例:
#include
#include
int main(void)
{
int value = 64;
int port = 0;
outportb(port, value);
printf("Value %d sent to port number %d
", value, port);
return 0;
}

墙角野猫

函数名: outportb
功 能: 输出字节到硬件端口中
用 法: void outportb(int port, char byte);
程序例:
#include
#include
int main(void)
{
int value = 64;
int port = 0;
outportb(port, value);
printf("Value %d sent to port number %d
", value, port);
return 0;
}

墙角野猫

函数名: outtext
功 能: 在视区显示一个字符串
用 法: void far outtext(char far *textstring);
程序例:
#include
#include
#include
#include
int main(void)
{
/* request auto detection */
int gdriver = DETECT, gmode, errorcode;
int midx, midy;
/* initialize graphics and local variables */
initgraph(&gdriver, &gmode, "");
/* read result of initialization */
errorcode = graphresult();
if (errorcode != grOk) /* an error occurred */
{
printf("Graphics error: %s
", grapherrormsg(errorcode));
printf("Press any key to halt:");
getch();
exit(1); /* terminate with an error code */
}
midx = getmaxx() / 2;
midy = getmaxy() / 2;
/* move the C.P. to the center of the screen */
moveto(midx, midy);
/* output text starting at the C.P. */
outtext("This ");
outtext("is ");
outtext("a ");
outtext("test.");
/* clean up */
getch();
closegraph();
return 0;
}

墙角野猫

函数名: outtextxy
功 能: 在指定位置显示一字符串
用 法: void far outtextxy(int x, int y, char *textstring);
程序例:
#include
#include
#include
#include
int main(void)
{
/* request auto detection */
int gdriver = DETECT, gmode, errorcode;
int midx, midy;
/* initialize graphics and local variables */
initgraph( &gdriver, &gmode, "");
/* read result of initialization */
errorcode = graphresult();
if (errorcode != grOk) /* an error occurred */
{
printf("Graphics error: %s
", grapherrormsg(errorcode));
printf("Press any key to halt:");
getch();
exit(1); /* terminate with an error code */
}
midx = getmaxx() / 2;
midy = getmaxy() / 2;
/* output text at the center of the screen*/
/* Note: the C.P. doesn't get changed.*/
outtextxy(midx, midy, "This is a test.");
/* clean up */
getch();
closegraph();
return 0;
}

墙角野猫

函数名: parsfnm
功 能: 分析文件名
用 法: char *parsfnm (char *cmdline, struct fcb *fcbptr, int option);
程序例:
#include
#include
#include
#include
int main(void)
{
char line[80];
struct fcb blk;
/* get file name */
printf("Enter drive and file name (no path - ie. a:file.dat)
");
gets(line);
/* put file name in fcb */
if (parsfnm(line, &blk, 1)== NULL)
printf("Error in parsfm call
");
else
printf("Drive #%d Name: %11s
", blk.fcb_drive, blk.fcb_name);
return 0;
}

墙角野猫

函数名: peek
功 能: 检查存储单元
用 法: int peek(int segment, unsigned offset);
程序例:
#include
#include
#include
int main(void)
{
int value = 0;
printf("The current status of your keyboard is:
");
value = peek(0x0040, 0x0017);
if (value & 1)
printf("Right shift on
");
else
printf("Right shift off
");
if (value & 2)
printf("Left shift on
");
else
printf("Left shift off
");
if (value & 4)
printf("Control key on
");
else
printf("Control key off
");
if (value & 8)
printf("Alt key on
");
else
printf("Alt key off
");
if (value & 16)
printf("Scroll lock on
");
else
printf("Scroll lock off
");
if (value & 32)
printf("Num lock on
");
else
printf("Num lock off
");
if (value & 64)
printf("Caps lock on
");
else
printf("Caps lock off
");
return 0;
}

墙角野猫

函数名: peekb
功 能: 检查存储单元
用 法: char peekb (int segment, unsigned offset);
程序例:
#include
#include
#include
int main(void)
{
int value = 0;
printf("The current status of your keyboard is:
");
value = peekb(0x0040, 0x0017);
if (value & 1)
printf("Right shift on
");
else
printf("Right shift off
");
if (value & 2)
printf("Left shift on
");
else
printf("Left shift off
");
if (value & 4)
printf("Control key on
");
else
printf("Control key off
");
if (value & 8)
printf("Alt key on
");
else
printf("Alt key off
");
if (value & 16)
printf("Scroll lock on
");
else
printf("Scroll lock off
");
if (value & 32)
printf("Num lock on
");
else
printf("Num lock off
");
if (value & 64)
printf("Caps lock on
");
else
printf("Caps lock off
");
return 0;
}

墙角野猫

函数名: perror
功 能: 系统错误信息
用 法: void perror(char *string);
程序例:
#include
int main(void)
{
FILE *fp;
fp = fopen("perror.dat", "r");
if (!fp)
perror("Unable to open file for reading");
return 0;
}

墙角野猫

函数名: pieslice
功 能: 绘制并填充一个扇形
用 法: void far pieslice(int x, int stanle, int endangle, int radius);
程序例:
#include
#include
#include
#include
int main(void)
{
/* request auto detection */
int gdriver = DETECT, gmode, errorcode;
int midx, midy;
int stangle = 45, endangle = 135, radius = 100;
/* initialize graphics and local variables */
initgraph(&gdriver, &gmode, "");
/* read result of initialization */
errorcode = graphresult();
if (errorcode != grOk) /* an error occurred */
{
printf("Graphics error: %s
", grapherrormsg(errorcode));
printf("Press any key to halt:");
getch();
exit(1); /* terminate with an error code */
}
midx = getmaxx() / 2;
midy = getmaxy() / 2;
/* set fill style and draw a pie slice */
setfillstyle(EMPTY_FILL, getmaxcolor());
pieslice(midx, midy, stangle, endangle, radius);
/* clean up */
getch();
closegraph();
return 0;
}