/* * at time mon day * at time wday * at time wday 'week' * */#include <stdio.h>#include <ctype.h>#include <time.h>#include <signal.h>#define HOUR 100#define HALFDAY	(12*HOUR)#define DAY	(24*HOUR)#define THISDAY "/usr/spool/at"char *days[] = {	"sunday",	"monday",	"tuesday",	"wednesday",	"thursday",	"friday",	"saturday",};struct monstr {	char *mname; 	int mlen;} months[] = {	{ "january", 31 },	{ "february", 28 },	{ "march", 31 },	{ "april", 30 },	{ "may", 31 },	{ "june", 30 },	{ "july", 31 },	{ "august", 31 },	{ "september", 30 },	{ "october", 31 },	{ "november", 30 },	{ "december", 31 },	{ 0, 0 },};char	fname[100];int	utime;  /* requested time in grains */int	now;	/* when is it */int	uday; /* day of year to be done */int	uyear; /* year */int	today; /* day of year today */FILE	*file;FILE	*ifile;char	**environ;char	*prefix();FILE	*popen();main(argc, argv)char **argv;{	extern onintr();	register c;	char pwbuf[100];	FILE *pwfil;	int larg;	/* argv[1] is the user's time: e.g.,  3AM */	/* argv[2] is a month name or day of week */	/* argv[3] is day of month or 'week' */	/* another argument might be an input file */	if (argc < 2) {		fprintf(stderr, "at: arg count\n");		exit(1);	}	makeutime(argv[1]);	larg = makeuday(argc,argv)+1;	if (uday==today && larg<=2 && utime<=now)		uday++;	c = uyear%4==0? 366: 365;	if (uday >= c) {		uday -= c;		uyear++;	}	filename(THISDAY, uyear, uday, utime);	ifile = stdin;	if (argc > larg)		ifile = fopen(argv[larg], "r");	if (ifile == NULL) {		fprintf(stderr, "at: cannot open input: %s\n", argv[larg]);		exit(1);	}	if (signal(SIGINT, SIG_IGN) != SIG_IGN)		signal(SIGINT, onintr);	file = fopen(fname, "a");	chmod(fname, 0644);	if (file == NULL) {		fprintf(stderr, "at: cannot open memo file\n");		exit(1);	}	if ((pwfil = popen("pwd", "r")) == NULL) {		fprintf(stderr, "at: can't execute pwd\n");		exit(1);	}	fgets(pwbuf, 100, pwfil);	pclose(pwfil);	fprintf(file, "cd %s", pwbuf);	if (environ) {		char **ep = environ;		while(*ep)			fprintf(file, "%s\n", *ep++);	}	while((c = getc(ifile)) != EOF) {		putc(c, file);	}	exit(0);}makeutime(pp)char *pp; {	register val;	register char *p;	/* p points to a user time */	p = pp;	val = 0;	while(isdigit(*p)) {		val = val*10+(*p++ -'0');	}	if (p-pp < 3)		val *= HOUR;	for (;;) {		switch(*p) {		case ':':			++p;			if (isdigit(*p)) {				if (isdigit(p[1])) {					val +=(10* *p + p[1] - 11*'0');					p += 2;					continue;				}			}			fprintf(stderr, "at: bad time format:\n");			exit(1);		case 'A':		case 'a':			if (val >= HALFDAY+HOUR)				val = DAY+1;  /* illegal */			if (val >= HALFDAY && val <(HALFDAY+HOUR))				val -= HALFDAY;			break;		case 'P':		case 'p':			if (val >= HALFDAY+HOUR)				val = DAY+1;  /* illegal */			if (val < HALFDAY)				val += HALFDAY;			break;		case 'n':		case 'N':			val = HALFDAY;			break;		case 'M':		case 'm':			val = 0;			break;		case '\0':		case ' ':			/* 24 hour time */			if (val == DAY)				val -= DAY;			break;		default:			fprintf(stderr, "at: bad time format\n");			exit(1);		}		break;	}	if (val < 0 || val >= DAY) {		fprintf(stderr, "at: time out of range\n");		exit(1);	}	if (val%HOUR >= 60) {		fprintf(stderr, "at: illegal minute field\n");		exit(1);	}	utime = val;}makeuday(argc,argv)char **argv;{	/* the presumption is that argv[2], argv[3] are either	   month day OR weekday [week].  Returns either 2 or 3 as last	   argument used */	/* first of all, what's today */	long tm;	int found = -1;	char **ps;	struct tm *detail, *localtime();	struct monstr *pt;	time(&tm);	detail = localtime(&tm);	uday = today = detail->tm_yday;	uyear = detail->tm_year;	now = detail->tm_hour*100+detail->tm_min;	if (argc<=2)		return(1);	/* is the next argument a month name ? */	for (pt=months; pt->mname; pt++) {		if (prefix(argv[2], pt->mname)) {			if (found<0)				found = pt-months;			else {				fprintf(stderr, "at: ambiguous month\n");				exit(1);			}		}	}	if (found>=0) {		if (argc<=3)			return(2);		uday = atoi(argv[3]) - 1;		if (uday<0) {			fprintf(stderr, "at: illegal day\n");			exit(1);		}		while(--found>=0)			uday += months[found].mlen;		if (detail->tm_year%4==0 && uday>59)			uday += 1;		return(3);	}	/* not a month, try day of week */	found = -1;	for (ps=days; ps<days+7; ps++) {		if (prefix(argv[2], *ps)) {			if (found<0)				found = ps-days;			else {				fprintf(stderr, "at: ambiguous day of week\n");				exit(1);			}		}	}	if (found<0)		return(1);	/* find next day of this sort */	uday = found - detail->tm_wday;	if (uday<=0)		uday += 7;	uday += today;	if (argc>3 && strcmp("week", argv[3])==0) {		uday += 7;		return(3);	}	return(2);}char *prefix(begin, full)char *begin, *full;{	int c;	while (c = *begin++) {		if (isupper(c))			c = tolower(c);		if (*full != c)			return(0);		else			full++;	}	return(full);}filename(dir, y, d, t)char *dir;{	register i;	for (i=0; ; i += 53) {		sprintf(fname, "%s/%02d.%03d.%04d.%02d", dir, y, d, t,		   (getpid()+i)%100);		if (access(fname, 0) == -1)			return;	}}onintr(){	unlink(fname);	exit(1);}