经典编程900例（c语言）（第二十六篇）

例315：

#include <conio.h>
#include <io.h>
#include <fcntl.h>
#include <sys\stat.h>
#include <stdlib.h>
#include <dos.h>

int main(int argc, char const *argv[])
{
    char buffer[128];
    int row, column;    

    clrscr();
    cprintf("Jamsa's 1001 C/C++ Tips\r\n");
    gettext(1, 1, 23, 1, buffer);

    while (!kbhit())
    {
        clrscr();
        row = 1 + random(24);
        column = 1 + random(58);
        puttext(column, row, column+22, row, buffer);
        delay(2000);
    }
    return 0;
}

例316：

#include <conio.h>
#include <io.h>
#include <fcntl.h>
#include <sys\stat.h>

int main(int argc, char const *argv[])
{
    char buffer[8000];
    int handle;

    if ((handle = creat("SAVESCR.DAT", S_IWRITE)) == -1) 
        cprintf("Error opening SAVESCRN.DAT\r\n");
    else
    {
        gettext(1, 1, 80, 25, buffer);
        write(handle, buffer, sizeof(buffer));
        close(handle);
    }
    return 0;
}

例317：

#include <conio.h>

int main(int argc, char const *argv[])
{
    union TextColor {
        struct {
            unsigned char foreground:4;
            unsigned char background:3;
            unsigned char blinking:1;
        } color_bits;
        unsigned char value;
    } colors;
    colors.color_bits.foreground = BLUE;
    colors.color_bits.background = RED;
    colors.color_bits.blinking = 1;

    textattr(colors.value);

    clrscr();
    cprintf("This is the new text colors\n");
    return 0;
}

例318：

#include <conio.h>

int main(int argc, char const *argv[])
{
    int color;

    for (color = 1; color < 16; color++)
    {
        textattr(color);
        cprintf("This is color %d\r\n", color);
    }

    textattr(128 + 15);
    cprintf("This is blinking\r\n");
    return 0;
}

例319：

#include <conio.h>

int main(int argc, char const *argv[])
{
    struct text_info text;

    gettextinfo(&text);

    cprintf("Screen coordinates %d,%d to %d,%d\r\n", text.wintop, text.winleft, text.winbottom, text.winright);
    cprintf("Text attribute %d Normal attribute %d\r\n", text.attribute, text.normattr);
    cprintf("Screen height %d width %d\r\n", text.screenheight, text.screenwidth);
    cprintf("Cursor position was row %d column %d\r\n", text.cury, text.curx);
    
    return 0;
}

例320：

#include <conio.h>

int main(int argc, char const *argv[])
{
    int color;

    for (color = 1; color < 16; color++)
    {
        textcolor(color);
        cprintf("This is color %d\r\n", color);
    }

    textcolor(128 + 15);
    cprintf("This is blinking\r\n");
    return 0;
}

例321：输入大写字母就换行输出

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

int main(int argc, char const *argv[])
{
    int letter;
    int done = 0;
    int uppercase_found = 0;

    do {
        letter = getch();

        if (islower(letter))
            putchar(letter);
        else
        {
            if (isupper(letter))
            {
                ungetch(letter);
                uppercase_found = 1;
                putchar('\n');
            }
            done = 1;
        }
    } while (! done);  

    if (uppercase_found)
        do {
            letter = getch();
            putchar(letter);
        } while (letter != '\r');
        
    return 0;
}

例322：打印文字后输出光标位置

#include <conio.h>

int main(int argc, char const *argv[])
{
    int row, column;

    clrscr();

    cprintf("This is line 1\r\n");
    cprintf("Line 2 is a little longer\r\n");
    cprintf("This is the last line");

    // 记录光标位置
    row = wherey();
    column = wherex();

    cprintf("\r\nThe cursor position was row %d column %d\n", row, column);
    return 0;
}

例323：设置窗口位置

#include <conio.h>

int main(int argc, char const *argv[])
{
    int i, j;

    // 前两个参数是左上角的坐标，也就是窗口的起点，后两个分别是长和宽 - tc可用
    window(1, 1, 40, 12);

    for (i = 0; i < 15; i++)
    {
        for (j = 0; j < 50; j++)
            cprintf("%d", j);
        cprintf("\r\n");
    }
    return 0;
}

例324：源文件的行号改变宏定义

#include <stdio.h>

int main(int argc, char const *argv[])
{
    // __LINE__  ：当前程序行的行号，表示为十进制整型常量
    // __FILE__  ：当前源文件名，表示字符串型常量
    printf("File %s: Successfully reached line %d\n", __FILE__, __LINE__);// File CHG_LINE.C: Successfully reached line 7


	// 指定下一行的__LINE__为100,__FILE__为FILENAME.C,重点是line的下一行是200
	#line 100 "FILENAME.C"

    printf("File %s: Successfully reached line %d\n", __FILE__, __LINE__);// File FILENAME.C: Successfully reached line 101
    return 0;
}

例325：判断是否为标准c程序的预定义宏

#include <stdio.h>

int main(int argc, char const *argv[])
{
    // 判断该文件是不是标准C程序
    #ifdef __STDC__
      printf("ANSI C compliance\n");
    #else
      printf("Not in ANSI C mode\n");
    #endif
    return 0;
}

例326：判断是否为标准c++的预定义宏

#include <stdio.h>

int main(int argc, char const *argv[])
{
    // 判断是否是c++代码
    #ifdef __cplusplus
      printf("Using C++\n");
    #else
      printf("Using C\n");
    #endif
    return 0;
}

例327：源文件名预定义宏__FILE__

#include <stdio.h>

int main(int argc, char const *argv[])
{
    printf("The file %s is under Beta testing\n", __FILE__);
    return 0;
}

例328：当前行号预定义宏__LINE__

#include <stdio.h>

int main(int argc, char const *argv[])
{
    printf("Successfully reached line %d\n", __LINE__); // Successfully reached line 5

    // Other statements here
   
    printf("Successfully reached line %d\n", __LINE__); // Successfully reached line 9
    return 0;
}