console监控窗口：动态显示信息

console监控窗口：动态显示信息（和top命令一样动态输出信息）

#include <time.h>
#include <string.h>

#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>

void show_new( char *str )
{
    static int need_clear = 0;
    char buff[1024] = {0x00};
    memset( buff, 0x00, sizeof(buff) );

    char back[1024] = {0x00};
    int len = 0;

    snprintf( buff, sizeof(buff),
            "************ \033[40;31m \033[0m************\n"
            "%s"
            "\033[40;33m----------------------------------------\033[0m\n"
            "\033[40;31m 提示： 退出 ctrl+c\033[0m\n"
            "\033[40;36m Version: epoller 3.5.4 \033[0m\n"
            "****************************************\n", str );

    int i = 0;
    len = strlen( buff );
    //生成回退格 \b
    while ( i < 512)
    {
        snprintf( back+i, sizeof(back)-i, "%s", "\b" );
        i++;
    }
    int line = 0;
    i = 0;
    while ( i < len )
    {
        if ( buff[i] == '\n' )
            line++;
        i++;
    }

    // 清除屏幕
    if ( need_clear != 0 )
    {
        for( i=0; i<line; i++  )
        {
            printf( "\033[1A" );//光标上移n行
            printf( back ); // 回退清空本行
        }
    }
    else
    {
        printf( "\033[2J" );//清除整个屏幕
        need_clear = 1;
    }
    printf( "\033[0;0H" );//定位到屏幕左上角

    // 打印新的内容
    printf( buff);
    //printf( "\033[?25l" );// 隐藏光标
    fflush(stdout);

}

int main(  int argc, char *argv[] )
{
    int i;
    for (i = 1; i <= 10000; ++i)
    {
        char buff[1024] = {0x00};
        memset( buff, 0x00, sizeof(buff) );

        char *user = getenv("USER");
        time_t t = time( NULL );
        snprintf( buff, sizeof(buff), "user: %s \ntime: %lu, index=%d\n", user, t, i );
        show_new( buff );
        sleep(1);
    }

    return 0;
}