4.3BSD-UWisc/src/usr.bin/at/at.c
/*
* Copyright (c) 1983 Regents of the University of California.
* All rights reserved. The Berkeley software License Agreement
* specifies the terms and conditions for redistribution.
*/
#ifndef lint
char copyright[] =
"@(#) Copyright (c) 1983 Regents of the University of California.\n\
All rights reserved.\n";
#endif not lint
#ifndef lint
static char sccsid[] = "@(#)at.c 5.4 (Berkeley) 5/28/86";
#endif not lint
/*
* Synopsis: at [-s] [-c] [-m] time [filename]
*
*
*
* Execute commands at a later date.
*
*
* Modifications by: Steve Wall
* Computer Systems Research Group
* University of California @ Berkeley
*
*/
#include <stdio.h>
#include <ctype.h>
#include <signal.h>
#include <pwd.h>
#include <sys/param.h>
#include <sys/time.h>
#include <sys/file.h>
#define HOUR 100 /* 1 hour (using military time) */
#define HALFDAY (12 * HOUR) /* half a day (12 hours) */
#define FULLDAY (24 * HOUR) /* a full day (24 hours) */
#define WEEK 1 /* day requested is 'week' */
#define DAY 2 /* day requested is a weekday */
#define MONTH 3 /* day requested is a month */
#define BOURNE "/bin/sh" /* run commands with Bourne shell*/
#define CSHELL "/bin/csh" /* run commands with C shell */
#define NODATEFOUND -1 /* no date was given on command line */
#define ATDIR "/usr/spool/at" /* spooling area */
#define LINSIZ 256 /* length of input buffer */
/*
* A table to identify potential command line values for "time".
*
* We need this so that we can do some decent error checking on the
* command line arguments. (This was inspired by the old "at", which
* accepted "at 900 jan 55" as valid input and other small bugs.
*/
struct datetypes {
int type;
char *name;
} dates_info[22] = {
{ DAY, "sunday" },
{ DAY, "monday" },
{ DAY, "tuesday" },
{ DAY, "wednesday" },
{ DAY, "thursday" },
{ DAY, "friday" },
{ DAY, "saturday" },
{ MONTH, "january" },
{ MONTH, "february" },
{ MONTH, "march" },
{ MONTH, "april" },
{ MONTH, "may" },
{ MONTH, "june" },
{ MONTH, "july" },
{ MONTH, "august" },
{ MONTH, "september" },
{ MONTH, "october" },
{ MONTH, "november" },
{ MONTH, "december" },
{ 0, ""},
};
/*
* Months of the year.
*/
char *months[13] = {
"jan", "feb", "mar", "apr", "may", "jun",
"jul", "aug", "sep", "oct", "nov", "dec", 0,
};
/*
* A table of the number of days in each month of the year.
*
* yeartable[0] -- normal year
* yeartable[1] -- leap year
*/
static int yeartable[2][13] = {
{ 0, 31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31},
{ 0, 31, 29, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31},
};
/*
* Structure holding the relevant values needed to create a spoolfile.
* "attime" will contain the info about when a job is to be run, and
* "nowtime" will contain info about what time the "at" command is in-
* voked.
*/
struct times {
int year; /* year that job is to be run */
int yday; /* day of year that job is to be run */
int mon; /* month of year that job is to be run*/
int mday; /* day of month that job is to be run */
int wday; /* day of week that job is to be run */
int hour; /* hour of day that job is to be run */
int min; /* min. of hour that job is to be run */
} attime, nowtime;
char atfile[100]; /* name of spoolfile "yy.ddd.hhhh.??" */
char *getenv(); /* get info on user's environment */
char **environ; /* user's environment */
FILE *spoolfile; /* spool file */
FILE *inputfile; /* input file ("stdin" or "filename") */
char *getwd(); /* used to get current directory info */
main(argc, argv)
int argc;
char **argv;
{
int c; /* scratch variable */
int usage(); /* print usage info and exit */
int cleanup(); /* do cleanup on an interrupt signal */
int dateindex = NODATEFOUND; /* if a day is specified, what option
is it? (mon day, week, dayofweek) */
char *shell = BOURNE; /* what shell do we use to run job? */
int shflag = 0; /* override the current shell and run
job using the Bourne Shell */
int cshflag = 0; /* override the current shell and run
job using the Cshell */
int mailflag = 0; /* send mail after a job has been run?*/
int standardin = 0; /* are we reading from stardard input */
char *tmp; /* scratch pointer */
char line[LINSIZ]; /* a line from input file */
char pwbuf[MAXPATHLEN]; /* the current working directory */
char *jobfile = "stdin"; /* file containing job to be run */
char *getname(); /* get the login name of a user */
int pid; /* For forking for security reasons */
argv++; argc--;
/*
* Interpret command line flags if they exist.
*/
while (argc > 0 && **argv == '-') {
(*argv)++;
while (**argv) switch (*(*argv)++) {
case 'c' : cshflag++;
shell = CSHELL;
break;
case 's' : shflag++;
shell = BOURNE;
break;
case 'm' : mailflag++;
break;
default : usage();
}
--argc, ++argv;
}
if (shflag && cshflag) {
fprintf(stderr,"ambiguous shell request.\n");
exit(1);
}
/*
* Get the time it is when "at" is invoked. We set both nowtime and
* attime to this value so that as we interpret the time the job is to
* be run we can compare the two values to determine such things as
* whether of not the job should be run the same day the "at" command
* is given, whether a job is to be run next year, etc.
*/
getnowtime(&nowtime, &attime);
#ifdef DEBUG
printit();
#endif
if (argc <= 0)
usage();
/*
* Interpret argv[1] and create the time of day that the job is to
* be run. This is the same function that was used in the old "at"
*/
maketime(&attime, *argv);
--argc; ++argv;
#ifdef DEBUG
printf("\n\nAFTER MAKETIME\n");
printit();
#endif
/*
* If argv[(2)] exists, this is a request to run a job on a certain
* day of year or a certain day of week.
*
* We send argv to the function "getdateindex" which returns the
* index value of the requested day in the table "dates_info"
* (see line 50 for table). If 'getdateindex" returns a NODATEFOUND,
* then the requested day format was not found in the table (usually
* this means that the argument is a "filename"). If the requested
* day is found, we continue to process command line arguments.
*/
if (argc > 0) {
if ((dateindex = getdateindex(*argv)) != NODATEFOUND) {
++argv; --argc;
/*
* Determine the day of year that the job will be run
* depending on the value of argv.
*/
makedayofyear(dateindex, &argv, &argc);
}
}
/*
* If we get to this point and "dateindex" is set to NODATEFOUND,
* then we are dealing with a request with only a "time" specified
* (i.e. at 400p) and perhaps 'week' specified (i.e. at 400p week).
* If 'week' is specified, we just set excecution for 7 days in the
* future. Otherwise, we need to check to see if the requested time
* has already passed for the current day. If it has, then we add
* one to the day of year that the job will be executed.
*/
if (dateindex == NODATEFOUND) {
int daysinyear;
if ((argc > 0) && (strcmp(*argv,"week") == 0)) {
attime.yday += 7;
++argv; --argc;
} else if (istomorrow())
++attime.yday;
daysinyear = isleap(attime.year) ? 366 : 365;
if (attime.yday >= daysinyear) {
attime.yday -= daysinyear;
++attime.year;
}
}
/*
* If no more arguments exist, then we are reading
* from standard input. Thus, we set the standard
* input flag (++standardin).
*/
if (argc <= 0)
++standardin;
#ifdef DEBUG
printf("\n\nAFTER ADDDAYS\n");
printit();
#endif
/*
* Start off assuming we're going to read from standard input,
* but if a filename has been given to read from, we will open it
* later.
*/
inputfile = stdin;
/*
* Create the filename for the spoolfile.
*/
makeatfile(atfile,attime.year,attime.yday,attime.hour,attime.min);
/*
* Open the spoolfile for writing.
*/
if ((spoolfile = fopen(atfile, "w")) == NULL){
perror(atfile);
exit(1);
}
/*
* Make the file not world readable.
*/
fchmod(fileno(spoolfile), 0400);
/*
* The protection mechanism works like this:
* We are running ruid=user, euid=daemon. So far we have been
* messing around in the spool directory, so we needed the
* daemon stuff. Now, we want to read the users file,
* so we must give up the daemon protection, but we might
* need the daemon's protection if the user interrupts and
* we need to remove the spool files.
* So, we fork and let the kid set the real and effective
* user id's to the user, so he can read everything of his
* own, but not his professor's final exam and not stuff
* owned by daemon. If the kid exits with non-zero status,
* that means that the user typed interrupt, and the parent
* (still with daemon permissions) removes the spool file.
*/
signal(SIGINT, SIG_IGN);
pid = fork();
if (pid == -1) {
perror("fork");
exit(1);
}
if (pid) {
int wpid, status;
/*
* We are the parent. If the kid has problems,
* cleanup the spool directory.
*/
wpid = wait(&status);
if (wpid != pid || status) {
cleanup();
exit(1);
}
/*
* The kid should have alread flushed the buffers.
*/
_exit(0);
}
/*
* Exit on interrupt.
*/
signal(SIGINT, SIG_DFL);
/*
* We are the kid, give up daemon permissions.
*/
setuid(getuid());
/*
* Open the input file with the user's permissions.
*/
if (!standardin) {
jobfile = *argv;
if ((inputfile = fopen(jobfile, "r")) == NULL) {
perror(jobfile);
exit(1);
}
}
/*
* If the inputfile is not from a tty then turn off standardin
* If the inputfile is a tty, put out a prompt now, instead of
* waiting for a lot of file activity to complete.
*/
if (!(isatty(fileno(inputfile))))
standardin = 0 ;
if (standardin) {
fputs("at> ", stdout);
fflush(stdout);
}
/*
* Determine what shell we should use to run the job. If the user
* didn't explicitly request that his/her current shell be over-
* ridden (shflag of cshflag) then we use the current shell.
*/
if ((!shflag) && (!cshflag) && (getenv("SHELL") != NULL))
shell = "$SHELL";
/*
* Put some standard information at the top of the spoolfile.
* This info is used by the other "at"-oriented programs (atq,
* atrm, atrun).
*/
fprintf(spoolfile, "# owner: %.127s\n",getname(getuid()));
fprintf(spoolfile, "# jobname: %.127s\n",jobfile);
fprintf(spoolfile, "# shell: sh\n");
fprintf(spoolfile, "# notify by mail: %s\n",(mailflag) ? "yes" : "no");
fprintf(spoolfile, "\n");
/*
* Set the modes for any files created by the job being run.
*/
c = umask(0);
umask(c);
fprintf(spoolfile, "umask %.1o\n", c);
/*
* Get the current working directory so we know what directory to
* run the job from.
*/
if (getwd(pwbuf) == NULL) {
fprintf(stderr, "at: can't get working directory\n");
exit(1);
}
fprintf(spoolfile, "cd %s\n", pwbuf);
/*
* Copy the user's environment to the spoolfile.
*/
if (environ) {
copyenvironment(&spoolfile);
}
/*
* Put in a line to run the proper shell using the rest of
* the file as input. Note that 'exec'ing the shell will
* cause sh() to leave a /tmp/sh### file around.
*/
fprintf(spoolfile,
"%s << '...the rest of this file is shell input'\n", shell);
/*
* Now that we have all the files set up, we can start reading in
* the job. (I added the prompt "at>" so that the user could tell
* when/if he/she was supposed to enter commands from standard
* input. The old "at" just sat there and didn't send any kind of
* message that said it was waiting for input if it was reading
* form standard input).
*/
while (fgets(line, LINSIZ, inputfile) != NULL) {
fputs(line, spoolfile);
if (standardin)
fputs("at> ", stdout);
}
if (standardin)
fputs("<EOT>\n", stdout); /* clean up the final output */
/*
* Close all files and change the mode of the spoolfile.
*/
fclose(inputfile);
fclose(spoolfile);
exit(0);
}
/*
* Copy the user's environment to the spoolfile in the syntax of the
* Bourne shell. After the environment is set up, the proper shell
* will be invoked.
*/
copyenvironment(spoolfile)
FILE **spoolfile;
{
char *tmp; /* scratch pointer */
char **environptr = environ; /* pointer to an environment setting */
while(*environptr) {
tmp = *environptr;
/*
* We don't want the termcap or terminal entry so skip them.
*/
if ((strncmp(tmp,"TERM=",5) == 0) ||
(strncmp(tmp,"TERMCAP=",8) == 0)) {
++environptr;
continue;
}
/*
* Set up the proper syntax.
*/
while (*tmp != '=')
fputc(*tmp++,*spoolfile);
fputc('=', *spoolfile);
fputc('\'' , *spoolfile);
++tmp;
/*
* Now copy the entry.
*/
while (*tmp) {
if (*tmp == '\'')
fputs("'\\''", *spoolfile);
else if (*tmp == '\n')
fputs("\\",*spoolfile);
else
fputc(*tmp, *spoolfile);
++tmp;
}
fputc('\'' , *spoolfile);
/*
* We need to "export" environment settings.
*/
fprintf(*spoolfile, "\nexport ");
tmp = *environptr;
while (*tmp != '=')
fputc(*tmp++,*spoolfile);
fputc('\n',*spoolfile);
++environptr;
}
return;
}
/*
* Create the filename for the spoolfile. The format is "yy.ddd.mmmm.??"
* where "yy" is the year the job will be run, "ddd" the day of year,
* "mmmm" the hour and minute, and "??" a scratch value used to dis-
* tinguish between two files that are to be run at the same time.
*/
makeatfile(atfile,year,dayofyear,hour,minute)
int year;
int hour;
int minute;
int dayofyear;
char *atfile;
{
int i; /* scratch variable */
for (i=0; ; i += 53) {
sprintf(atfile, "%s/%02d.%03d.%02d%02d.%02d", ATDIR, year,
dayofyear, hour, minute, (getpid() + i) % 100);
/*
* Make sure that the file name that we've created is unique.
*/
if (access(atfile, F_OK) == -1)
return;
}
}
/*
* Has the requested time already passed for the currrent day? If so, we
* will run the job "tomorrow".
*/
istomorrow()
{
if (attime.hour < nowtime.hour)
return(1);
if ((attime.hour == nowtime.hour) && (attime.min < nowtime.min))
return(1);
return(0);
}
/*
* Debugging wreckage.
*/
printit()
{
printf("YEAR\tnowtime: %d\tattime: %d\n",nowtime.year,attime.year);
printf("YDAY\tnowtime: %d\tattime: %d\n",nowtime.yday,attime.yday);
printf("MON\tnowtime: %d\tattime: %d\n",nowtime.mon,attime.mon);
printf("MONDAY\tnowtime: %d\tattime: %d\n",nowtime.mday,attime.mday);
printf("WDAY\tnowtime: %d\tattime: %d\n",nowtime.wday,attime.wday);
printf("HOUR\tnowtime: %d\tattime: %d\n",nowtime.hour,attime.hour);
printf("MIN\tnowtime: %d\tattime: %d\n",nowtime.min,attime.min);
}
/*
* Calculate the day of year that the job will be executed.
* The av,ac arguments are ptrs to argv,argc; updated as necessary.
*/
makedayofyear(dateindex, av, ac)
int dateindex;
char ***av;
int *ac;
{
char **argv = *av; /* imitate argc,argv and update args at end */
int argc = *ac;
char *ptr; /* scratch pointer */
struct datetypes *daterequested; /* pointer to information about
the type of date option
we're dealing with */
daterequested = &dates_info[dateindex];
/*
* If we're dealing with a day of week, determine the number of days
* in the future the next day of this type will fall on. Add this
* value to "attime.yday".
*/
if (daterequested->type == DAY) {
if (attime.wday < dateindex)
attime.yday += dateindex - attime.wday;
else if(attime.wday > dateindex)
attime.yday += (7 - attime.wday) + dateindex;
else attime.yday += 7;
}
/*
* If we're dealing with a month and day of month, determine the
* day of year that this date will fall on.
*/
if (daterequested->type == MONTH) {
/*
* If a day of month isn't specified, print a message
* and exit.
*/
if (argc <= 0) {
fprintf(stderr,"day of month not specified.\n");
exit(1);
}
/*
* Scan the day of month value and make sure that it
* has no characters in it. If characters are found or
* the day requested is zero, print a message and exit.
*/
ptr = *argv;
while (isdigit(*ptr))
++ptr;
if ((*ptr != '\0') || (atoi(*argv) == 0)) {
fprintf(stderr,"\"%s\": illegal day of month\n",*argv);
exit(1);
}
/*
* Set the month of year and day of month values. Since
* the first 7 values in our dateinfo table do not deal
* with month names, we subtract 7 from the month of year
* value.
*/
attime.mon = (dateindex - 7);
attime.mday = (atoi(*argv) - 1);
/*
* Test the day of month value to make sure that the
* value is legal.
*/
if ((attime.mday + 1) >
yeartable[isleap(attime.year)][attime.mon + 1]) {
fprintf(stderr,"\"%s\": illegal day of month\n",*argv);
exit(1);
}
/*
* Finally, we determine the day of year.
*/
attime.yday = (countdays());
++argv; --argc;
}
/*
* If 'week' is specified, add 7 to the day of year.
*/
if ((argc > 0) && (strcmp(*argv,"week") == 0)) {
attime.yday += 7;
++argv; --argc;
}
/*
* Now that all that is done, see if the requested execution time
* has already passed for this year, and if it has, set execution
* for next year.
*/
if (isnextyear())
++attime.year;
/*
* Finally, reflect the updated argc,argv to the caller
*/
*av = argv;
*ac = argc;
}
/*
* Should the job be run next year? We check for the following situations:
*
* 1) the requested time has already passed for the current year.
* 2) the day of year is greater than the number of days in the year.
*
* If either of these tests succeed, we increment "attime.year" by 1.
* If #2 is true, we also subtract the number of days in the current year
* from "attime.yday". #2 can only occur if someone specifies a job to
* be run "tomorrow" on Dec. 31 or if they specify a job to be run a
* 'week' later and the date is at least Dec. 24. (I think so anyway)
*/
isnextyear()
{ register daysinyear;
if (attime.yday < nowtime.yday)
return(1);
if ((attime.yday == nowtime.yday) && (attime.hour < nowtime.hour))
return(1);
daysinyear = isleap(attime.year) ? 366 : 365;
if (attime.yday >= daysinyear) {
attime.yday -= daysinyear;
return(1);
}
if (attime.yday > (isleap(attime.year) ? 366 : 365)) {
attime.yday -= (isleap(attime.year) ? 366 : 365);
return(1);
}
return(0);
}
/*
* Determine the day of year given a month and day of month value.
*/
countdays()
{
int leap; /* are we dealing with a leap year? */
int dayofyear; /* the day of year after conversion */
int monthofyear; /* the month of year that we are
dealing with */
/*
* Are we dealing with a leap year?
*/
leap = isleap(attime.year);
monthofyear = attime.mon;
dayofyear = attime.mday;
/*
* Determine the day of year.
*/
while (monthofyear > 0)
dayofyear += yeartable[leap][monthofyear--];
return(dayofyear);
}
/*
* Is a year a leap year?
*/
isleap(year)
int year;
{
return((year%4 == 0 && year%100 != 0) || year%100 == 0);
}
getdateindex(date)
char *date;
{
int i = 0;
struct datetypes *ptr;
ptr = dates_info;
for (ptr = dates_info; ptr->type != 0; ptr++, i++) {
if (isprefix(date, ptr->name))
return(i);
}
return(NODATEFOUND);
}
isprefix(prefix, fullname)
char *prefix, *fullname;
{
char ch;
char *ptr;
char *ptr1;
ptr = prefix;
ptr1 = fullname;
while (*ptr) {
ch = *ptr;
if (isupper(ch))
ch = tolower(ch);
if (ch != *ptr1++)
return(0);
++ptr;
}
return(1);
}
getnowtime(nowtime, attime)
struct times *nowtime;
struct times *attime;
{
struct tm *now;
struct timeval time;
struct timezone zone;
if (gettimeofday(&time,&zone) < 0) {
perror("gettimeofday");
exit(1);
}
now = localtime(&time.tv_sec);
attime->year = nowtime->year = now->tm_year;
attime->yday = nowtime->yday = now->tm_yday;
attime->mon = nowtime->mon = now->tm_mon;
attime->mday = nowtime->mday = now->tm_mday;
attime->wday = nowtime->wday = now->tm_wday;
attime->hour = nowtime->hour = now->tm_hour;
attime->min = nowtime->min = now->tm_min;
}
/*
* This is the same routine used in the old "at", so I won't bother
* commenting it. It'll give you an idea of what the code looked
* like when I got it.
*/
maketime(attime,ptr)
char *ptr;
struct times *attime;
{
int val;
char *p;
p = ptr;
val = 0;
while(isdigit(*p)) {
val = val*10+(*p++ -'0');
}
if (p-ptr < 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, "bad time format:\n");
exit(1);
case 'A':
case 'a':
if (val >= HALFDAY+HOUR)
val = FULLDAY+1; /* illegal */
if (val >= HALFDAY && val <(HALFDAY+HOUR))
val -= HALFDAY;
break;
case 'P':
case 'p':
if (val >= HALFDAY+HOUR)
val = FULLDAY+1; /* illegal */
if (val < HALFDAY)
val += HALFDAY;
break;
case 'n':
case 'N':
if ((val == 0) || (val == HALFDAY))
val = HALFDAY;
else
val = FULLDAY+1; /* illegal */
break;
case 'M':
case 'm':
if ((val == 0) || (val == HALFDAY))
val = 0;
else
val = FULLDAY+1; /* illegal */
break;
case '\0':
case ' ':
/* 24 hour time */
if (val == FULLDAY)
val -= FULLDAY;
break;
default:
fprintf(stderr, "bad time format\n");
exit(1);
}
break;
}
if (val < 0 || val >= FULLDAY) {
fprintf(stderr, "time out of range\n");
exit(1);
}
if (val%HOUR >= 60) {
fprintf(stderr, "illegal minute field\n");
exit(1);
}
attime->hour = val/HOUR;
attime->min = val%HOUR;
}
/*
* Get the full login name of a person using his/her user id.
*/
char *
getname(uid)
int uid;
{
struct passwd *pwdinfo; /* password info structure */
if ((pwdinfo = getpwuid(uid)) == 0) {
perror(uid);
exit(1);
}
return(pwdinfo->pw_name);
}
/*
* Do general cleanup.
*/
cleanup()
{
if (unlink(atfile) == -1)
perror(atfile);
exit(1);
}
/*
* Print usage info and exit.
*/
usage()
{
fprintf(stderr,"usage: at [-csm] time [date] [filename]\n");
exit(1);
}