/* at - run a command at a specified time Author: Jan Looyen */ #include <sys/types.h> #include <time.h> #include <fcntl.h> #include <stdio.h> #define STARTDAY 0 /* see ctime(3) */ #define LEAPDAY STARTDAY+59 #define MAXDAYNR STARTDAY+365 #define NODAY -2 main(argc, argv, envp) int argc; char **argv, **envp; { int i, count, ltim, year, getltim(), getlday(), lday = NODAY; char c, buf[10], job[30], *dp, *sp; struct tm *p, *localtime(); long clock; FILE *fp, *pin, *popen(); /*-------------------------------------------------------------------------* * check arguments & pipe to "pwd" * *-------------------------------------------------------------------------*/ if (argc < 2 || argc > 5) { fprintf(stderr, "Usage: %s time [month day] [file]\n", argv[0]); exit(1); } if ((ltim = getltim(argv[1])) == -1) { fprintf(stderr, "%s: wrong time specification\n", argv[0]); exit(1); } if ((argc == 4 || argc == 5) && (lday = getlday(argv[2], argv[3])) == -1) { fprintf(stderr, "%s: wrong date specification\n", argv[0]); exit(1); } if ((argc == 3 || argc == 5) && open(argv[argc - 1], O_RDONLY) == -1) { fprintf(stderr, "%s: cannot find: %s\n", argv[0], argv[argc - 1]); exit(1); } if ((pin = popen("pwd", "r")) == NULL) { fprintf(stderr, "%s: cannot open pipe to cmd 'pwd'\n", argv[0]); exit(1); } /*-------------------------------------------------------------------------* * determine execution time and create 'at' job file * *-------------------------------------------------------------------------*/ time(&clock); p = localtime(&clock); year = p->tm_year; if (lday == NODAY) { /* no [month day] given */ lday = p->tm_yday; if (ltim <= (p->tm_hour * 100 + p->tm_min)) { lday++; if (lday == MAXDAYNR && (year % 4) || lday == MAXDAYNR + 1) { lday = STARTDAY; year++; } } } else switch (year % 4) { case 0: if (lday < p->tm_yday || lday == p->tm_yday && ltim <= (p->tm_hour * 100 + p->tm_min)) { year++; if (lday > LEAPDAY) lday--; } break; case 1: case 2: if (lday > LEAPDAY) lday--; if (lday < p->tm_yday || lday == p->tm_yday && ltim <= (p->tm_hour * 100 + p->tm_min)) year++; break; case 3: if (lday < ((lday > LEAPDAY) ? p->tm_yday + 1 : p->tm_yday) || lday == ((lday > LEAPDAY) ? p->tm_yday + 1 : p->tm_yday) && ltim <= (p->tm_hour * 100 + p->tm_min)) year++; else if (lday > LEAPDAY) lday--; break; } sprintf(job, "/usr/spool/at/%02d.%03d.%04d.%02d", year % 100, lday, ltim, getpid() % 100); if ((fp = fopen(job, "w")) == NULL) { fprintf(stderr, "%s: cannot create %s\n", argv[0], job); exit(1); } /*-------------------------------------------------------------------------* * write environment and command(s) to 'at'job file * *-------------------------------------------------------------------------*/ i = 0; while (envp[i] != NULL) { count = 1; dp = buf; sp = envp[i]; while ((*dp++ = *sp++) != '=') count++; *--dp = '\0'; fprintf(fp, "%s='%s'; export %s\n", buf, &envp[i++][count], buf); } fprintf(fp, "cd "); while ((c = getc(pin)) != EOF) putc(c, fp); fprintf(fp, "umask %o\n", umask()); if (argc == 3 || argc == 5) fprintf(fp, "%s\n", argv[argc - 1]); else /* read from stdinput */ while ((c = getchar()) != EOF) putc(c, fp); printf("%s: %s created\n", argv[0], job); exit(0); } /*-------------------------------------------------------------------------* * getltim() return((time OK) ? daytime : -1) * *-------------------------------------------------------------------------*/ getltim(t) char *t; { if (t[4] == '\0' && t[3] >= '0' && t[3] <= '9' && t[2] >= '0' && t[2] <= '5' && t[1] >= '0' && t[1] <= '9' && (t[0] == '0' || t[0] == '1' || t[1] <= '3' && t[0] == '2')) return(atoi(t)); else return(-1); } /*-------------------------------------------------------------------------* * getlday() return ((date OK) ? yearday : -1) * *-------------------------------------------------------------------------*/ getlday(m, d) char *m, *d; { int i, month, day, im; static int cumday[] = {0, 0, 31, 60, 91, 121, 152, 182, 213, 244, 274, 305, 335}; static struct date { char *mon; int dcnt; } *pc, kal[] = { "Jan", 31, "Feb", 29, "Mar", 31, "Apr", 30, "May", 31, "Jun", 30, "Jul", 31, "Aug", 31, "Sep", 30, "Oct", 31, "Nov", 30, "Dec", 31 }; pc = kal; im = (digitstring(m)) ? atoi(m) : 0; m[0] &= 0337; for (i = 1; i < 13 && strcmp(m, pc->mon) && im != i; i++, pc++); if (i < 13 && (day = (digitstring(d)) ? atoi(d) : 0) && day <= pc->dcnt) { if (!STARTDAY) day--; return(day + cumday[i]); } else return(-1); } digitstring(s) char *s; { while (*s >= '0' && *s <= '9') s++; return((*s == '\0') ? 1 : 0); }