C语言函数大全--d开头的函数

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

/* names of the various cards supported */
char *dname[] = {
    "requests detection",
    "a CGA",
    "an MCGA",
    "an EGA",
    "a 64K EGA",
    "a monochrome EGA",
    "an IBM 8514",
    "a Hercules monochrome",
    "an AT&T 6300 PC",
    "a VGA",
    "an IBM 3270 PC"
};

int main(void)
{
    int gdriver, gmode, errorcode;

    detectgraph(&gdriver, &gmode);

    initgraph(&gdriver, &gmode, "");

    errorcode = graphresult();

    if (errorcode != grOk)
    {
        printf("Graphics error: %s\n", grapherrormsg(errorcode));
        printf("Press any key to halt:");
        getch();
        exit(1);
    }

    printf("You have [%s] video display card.\n", dname[gdriver]);
    printf("Press any key to halt:");
    getch();
    return 0;
}

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

int main(void)
{
    time_t first, second; // time_t 相当于 long
    first = time(NULL);  // Gets system time 
    getchar();
    second = time(NULL); // Gets system time again 
    printf("The difference is: %lf seconds\n", difftime(second, first));
    return 0;
}

// 中断服务示例
#include <stdio.h>
#include <dos.h>
#include <conio.h>
// 定义一个宏INTR，代表时钟中断的十六进制向量值
#define INTR 0X1C  
// 声明一个函数指针oldhandler，该指针指向一个没有参数且返回void的函数。
// 这种函数通常用于中断处理程序
void interrupt (*oldhandler)(void);

int count=0;

void interrupt handler(void)
{
    // 禁用其他中断，确保此中断处理程序执行完毕前不再响应其他中断
    disable();
    count++;
    // 启用其他中断
    enable(); 
    // 调用原先的中断处理程序
    (*oldhandler)();
}

int main(void)
{
    // 获取时钟中断的原始处理程序，并将其存储在oldhandler指向的函数中
    oldhandler = getvect(INTR);
    // 将时钟中断的处理程序设置为handler函数
    setvect(INTR, handler);

    while (count < 20)
        printf("count is %d\n",count);
    // 恢复时钟中断的原始处理程序
    setvect(INTR, oldhandler);

    return 0;
}

#include <stdio.h>
#include <math.h>

int main(void)
{
    div_t x = div(10,3);
    // 商 和 余数
    printf("10 div 3 = %d remainder %d\n", x.quot, x.rem);
    return 0;
}

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

int main(void)
{
    // request auto detection
    int gdriver = DETECT, gmode, errorcode;
    int maxx, maxy;

    // our polygon array
    int poly[10];

    // 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();
        // terminate with an error code
        exit(1);
    }

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

    poly[0] = 20;
    poly[1] = maxy / 2;

    poly[2] = maxx - 20;
    poly[3] = 20;

    poly[4] = maxx - 50;
    poly[5] = maxy - 20;

    poly[6] = maxx / 2;
    poly[7] = maxy / 2;

    // drawpoly doesn't automatically close the polygon, so we close it.

    poly[8] = poly[0];
    poly[9] = poly[1];

    // draw the polygon
    drawpoly(5, poly);

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

#include <sys/types.h>
#include <sys/stat.h>
#include <string.h>
#include <stdio.h>
#include <conio.h>
#include <fcntl.h>
#include <io.h>

void flush(FILE *stream);

int main(void)
{
    FILE *fp;
    char msg[] = "This is a test";

    fp = fopen("STU.FIL", "w");

    fwrite(msg, strlen(msg), 1, fp);

    int handle;

    handle = open("temp.txt", _O_RDWR | _O_CREAT, _S_IREAD | _S_IWRITE);
    printf("file hanlde : %d\n", handle);

    printf("Press any key to flush STU.FIL:");
    getchar();

    flush(fp);

    printf("\nFile was flushed, Press any key to quit:");
    getchar();
    return 0;
}

void flush(FILE *stream)
{
    int duphandle;

    fflush(stream);

    duphandle = dup(fileno(stream));

    printf("duplicate file hanlde : %d", duphandle);

    close(duphandle);
}

#include <sys\stat.h>
#include <stdio.h>
#include <string.h>
#include <fcntl.h>
#include <io.h>

int main(void)
{
    #define STDOUT 1

    int handle, oldstdout;
    char msg[] = "This is a test1";

    handle = open("STU.FIL", O_CREAT | O_RDWR, S_IREAD | S_IWRITE);
    printf("open file handle : %d\n", handle);

    oldstdout = dup(STDOUT);
    printf("dup file handle : %d", oldstdout);

    dup2(handle, STDOUT);

    close(handle);

    write(STDOUT, msg, strlen(msg));

    dup2(oldstdout, STDOUT);

    close(oldstdout);

    return 0;
}