Bell 32V development

[unix-history] / usr / src / cmd / date.c

/*
* date : print date
* date YYMMDDHHMM[.SS] : set date, if allowed
* date -u ... : date in GMT
*/
#include <time.h>
#include <sys/types.h>
#include <sys/timeb.h>
#include <utmp.h>
long    timbuf;
char    *ap, *ep, *sp;
int     uflag;

char    *timezone();
static  int     dmsize[12] =
{
       31,
       28,
       31,
       30,
       31,
       30,
       31,
       31,
       30,
       31,
       30,
       31
};

struct utmp wtmp[2] = { {"|", "", 0}, {"{", "", 0}};

char    *ctime();
char    *asctime();
struct  tm *localtime();
struct  tm *gmtime();

main(argc, argv)
char *argv[];
{
       register char *tzn;
       struct timeb info;
       int wf, rc;

       rc = 0;
       ftime(&info);
       if (argc>1 && argv[1][0]=='-' && argv[1][1]=='u') {
               argc--;
               argv++;
               uflag++;
       }
       if(argc > 1) {
               ap = argv[1];
               if (gtime()) {
                       printf("date: bad conversion\n");
                       exit(1);
               }
               /* convert to GMT assuming local time */
               if (uflag==0) {
                       timbuf += (long)info.timezone*60;
                       /* now fix up local daylight time */
                       if(localtime(&timbuf)->tm_isdst)
                               timbuf -= 60*60;
               }
               time(&wtmp[0].ut_time);
               if(stime(&timbuf) < 0) {
                       rc++;
                       printf("date: no permission\n");
               } else if ((wf = open("/usr/adm/wtmp", 1)) >= 0) {
                       time(&wtmp[1].ut_time);
                       lseek(wf, 0L, 2);
                       write(wf, (char *)wtmp, sizeof(wtmp));
                       close(wf);
               }
       }
       if (rc==0)
               time(&timbuf);
       if(uflag) {
               ap = asctime(gmtime(&timbuf));
               tzn = "GMT";
       } else {
               struct tm *tp;
               tp = localtime(&timbuf);
               ap = asctime(tp);
               tzn = timezone(info.timezone, tp->tm_isdst);
       }
       printf("%.20s", ap);
       if (tzn)
               printf("%s", tzn);
       printf("%s", ap+19);
       exit(rc);
}

gtime()
{
       register int i, year, month;
       int day, hour, mins, secs;
       struct tm *L;
       char x;

       ep=ap;
       while(*ep) ep++;
       sp=ap;
       while(sp<ep) {
               x = *sp;
               *sp++ = *--ep;
               *ep = x;
       }
       sp=ap;
       time(&timbuf);
       L=localtime(&timbuf);
       secs = gp(-1);
       if(*sp!='.') {
               mins=secs;
               secs=0;
       } else {sp++;
               mins = gp(-1);
       }
       hour = gp(-1);
       day = gp(L->tm_mday);
       month = gp(L->tm_mon+1);
       year = gp(L->tm_year);
       if(*sp)
               return(1);
       if( month<1 || month>12 ||
           day<1 || day>31 ||
           mins<0 || mins>59 ||
           secs<0 || secs>59)
               return(1);
       if (hour==24) {
               hour=0; day++;
       }
       if (hour<0 || hour>23)
               return(1);
       timbuf = 0;
       year += 1900;
       for(i=1970; i<year; i++)
               timbuf += dysize(i);
       /* Leap year */
       if (dysize(year)==366 && month >= 3)
               timbuf++;
       while(--month)
               timbuf += dmsize[month-1];
       timbuf += day-1;
       timbuf = 24*timbuf + hour;
       timbuf = 60*timbuf + mins;
       timbuf = 60*timbuf + secs;
       return(0);

}

gp(dfault)
{
       register int c, d;

       if(*sp==0)
               return(dfault);
       c = (*sp++)-'0';
       d = (*sp ? (*sp++)-'0' : 0);
       if(c<0 || c>9 || d<0 || d>9)
               return(-1);
       return(c+10*d);
}