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

int getdate_err;

struct tm* getdate(const char* s) {
    static struct tm tmbuf;
    struct tm* ret = 0;
    char* datemsk = getenv("DATEMSK");
    FILE* f = 0;
    char fmt[100], *p;

    if (!datemsk) {
        getdate_err = 1;
        goto out;
    }

    f = fopen(datemsk, "rbe");
    if (!f) {
        if (errno == ENOMEM)
            getdate_err = 6;
        else
            getdate_err = 2;
        goto out;
    }

    while (fgets(fmt, sizeof fmt, f)) {
        p = strptime(s, fmt, &tmbuf);
        if (p && !*p) {
            ret = &tmbuf;
            goto out;
        }
    }

    getdate_err = 7;
out:
    if (f)
        fclose(f);
    return ret;
}