简单实现日历功能

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

int  leap_year(int year);
void show_calen(int day, int mon, int year, int week);
int week_df(int day, int mon, int year);
void show_year(int year);

int mon_d[12] = {31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31};
int mon_d_l[12] = {31, 29, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31};

int main(int argc, char **argv)
{
    int year = 0;
    int mon = 0;
    //int mon_d[12] = {31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31};
    //int mon_d_l[12] = {31, 29, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31};
    int day = 0;
    int week;

    if(1 == argc || 3 == argc || 4 < argc)
    {
        printf("reage: ./a.out year or  ./a.out day mon year\n");
        goto err0;
    }
    
    if(0 != atoi(argv[3]))
    {
        year = atoi(argv[3]);
        mon = atoi(argv[2]);
        day = atoi(argv[1]);

        week = week_df(day, mon, year);
        show_calen(day, mon, year, week);
    }
    else
    {
        year = atoi(argv[1]);

        show_year(year);
    }
    /*else if(0 != atoi(argv[2]))
    {
        day = atoi(argv[2]);
        mon = atoi(argv[1]);
    }
    else
    {
         year = atoi(argv[1]);
    }*/
    /*if(NULL != argv[2])
        mon = atoi(argv[2]);
    if(atoi(argv[1]) <= 31)
    {
        day = atoi(argv[1]);
    }
    else
    {
        printf("day 1-31");
        goto err0;
    }*/

    

     return 0;
err0:
    return 1;
}

int  leap_year(int year)
{
    if((0 == year % 4 && 0 != year % 100) || 0 == year % 400)
    {
        return 1;
    }

    return 0;
}

int week_df(int day, int mon, int year)
{
    int i;
    int leap_count = 0;
    int year_cose;
    int mon_cose = 0;
    int day_cose;
    int week;
    for(i = 1900; i < year; i++)
    {
        if(leap_year(i))
        {
            leap_count++;
        }
    }
    //printf("%d\n", leap_count);

    year_cose = year - 1900;

    if(leap_year(year))
    {
        for(i = 0; i < mon - 1; i++)
        {
            mon_cose += mon_d_l[i];
        }
    }
    else
    {
        for(i = 0; i < mon - 1; i++)
        {
            mon_cose += mon_d[i];
        }
    }
    
    day_cose = 365 * year_cose + leap_count + mon_cose + 1;
    //printf("%d\n", day_cose);
    week = day_cose % 7;
    
    return week;
}

void show_calen(int day, int mon, int year, int week)
{
    int i, j;
    printf("\033[%dC%d年%d月%d日\n", 4, year, mon, day);
    printf("日 一 二 三 四 五 六\n");
    for(j = 0; j < week; j++)
    {
        printf("   ");
    }

    if(leap_year(year))
    {
        for(i = 1; i <= mon_d_l[mon - 1]; i++, j++)
        {
            if(j % 7 == 0)
                putchar('\n');
            if(i == day)
            {
                printf("\033[30;47m%2d\033[0m ", i);
            }
            else
            {
                printf("%2d ", i);
            }
        }
    }
    else
    {
        for(i = 1; i <= mon_d[mon - 1]; i++, j++)
        {
            if(j % 7 == 0)
                putchar('\n');
            if(i == day)
            {
                printf("\033[30;47m%2d\033[0m ", i);
            }
            else
            {
                printf("%2d ", i);
            }
        }
    }
    putchar('\n');
}

void show_year(int year)
{
    int week;
    int i, j, z;
    int l = 1;
    int l_start, l_end;
    int w = 1;

    system("clear");
    for(z = 1; z <= 12; z++)
    {
        week = week_df(1, z, year);
        l_start = l;
        printf("\033[%d;%dH", l, w);
        printf("\033[%dC%d年%d月\n", 6, year, z);
        printf("日 一 二 三 四 五 六\n");
        printf("\033[%d;%dH", ++l, w);
        for(j = 0; j < week; j++)
        {
            printf("   ");
        }

        if(leap_year(year))
        {
            for(i = 1; i <= mon_d_l[z - 1]; i++, j++)
            {
                if(j % 7 == 0 && j != 0)
                {
                    l++;
                    //putchar('\n');
                    printf("\033[%d;%dH", l, w);
                }
                printf("%2d ", i);
            }
        }
        else
        {
            for(i = 1; i <= mon_d[z - 1]; i++, j++)
            {
                if(j % 7 == 0 && j != 0)
                {
                    l++;
                    printf("\033[%d;%dH", l, w);
                }
                printf("%2d ", i);
            }
        }
        putchar('\n');
        l++;
        if(l > l_end)
            l_end = l;

        if(z % 3 == 0)
        {
            w = 1;
            l = l_end;
        }
        else
        {
            w = w + 25;
            l = l_start;
        }
    }
}