.bin/clock.c


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#if 0
exec cc -Wall -Wextra -pedantic $@ -o $(dirname $0)/clock $0
#endif

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

int main() {
    time_t timestamp = time(NULL);
    if (timestamp < 0) err(EX_OSERR, "time");

    struct tm *clock = localtime(&timestamp);
    if (!clock) err(EX_OSERR, "localtime");

    int hour = clock->tm_hour;
    int next = (hour + 1) % 24;

    switch ((clock->tm_min + 3) / 6) {
        case  0: printf("....%02d....\n", hour); break;
        case  1: printf("...%02d.....\n", hour); break;
        case  2: printf("..%02d......\n", hour); break;
        case  3: printf(".%02d.......\n", hour); break;
        case  4: printf("%02d........\n", hour); break;
        case  5: printf("%d........%d\n", hour % 10, next / 10); break;
        case  6: printf("........%02d\n", next); break;
        case  7: printf(".......%02d.\n", next); break;
        case  8: printf("......%02d..\n", next); break;
        case  9: printf(".....%02d...\n", next); break;
        case 10: printf("....%02d....\n", next); break;
    }

    return 0;
}