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386BSD 0.1 development
[unix-history] / usr / src / libexec / crond / entry.c
#if !defined(lint) && !defined(LINT)
static char rcsid[] = "$Header: entry.c,v 2.1 90/07/18 00:23:41 vixie Exp $";
#endif
/* vix 26jan87 [RCS'd; rest of log is in RCS file]
* vix 01jan87 [added line-level error recovery]
* vix 31dec86 [added /step to the from-to range, per bob@acornrc]
* vix 30dec86 [written]
*/
/* Copyright 1988,1990 by Paul Vixie
* All rights reserved
*
* Distribute freely, except: don't remove my name from the source or
* documentation (don't take credit for my work), mark your changes (don't
* get me blamed for your possible bugs), don't alter or remove this
* notice. May be sold if buildable source is provided to buyer. No
* warrantee of any kind, express or implied, is included with this
* software; use at your own risk, responsibility for damages (if any) to
* anyone resulting from the use of this software rests entirely with the
* user.
*
* Send bug reports, bug fixes, enhancements, requests, flames, etc., and
* I'll try to keep a version up to date. I can be reached as follows:
* Paul Vixie, 329 Noe Street, San Francisco, CA, 94114, (415) 864-7013,
* paul@vixie.sf.ca.us || {hoptoad,pacbell,decwrl,crash}!vixie!paul
*/
#include "cron.h"
typedef enum
{e_none, e_minute, e_hour, e_dom, e_month, e_dow, e_cmd, e_timespec}
ecode_e;
static char *ecodes[] =
{
"no error",
"bad minute",
"bad hour",
"bad day-of-month",
"bad month",
"bad day-of-week",
"bad command",
"bad time specifier"
};
void
free_entry(e)
entry *e;
{
int free();
(void) free(e->cmd);
(void) free(e);
}
entry *
load_entry(file, error_func)
FILE *file;
void (*error_func)();
{
/* this function reads one crontab entry -- the next -- from a file.
* it skips any leading blank lines, ignores comments, and returns
* EOF if for any reason the entry can't be read and parsed.
*
* the entry IS parsed here, btw.
*
* syntax:
* minutes hours doms months dows cmd\n
*/
extern int free();
extern char *malloc(), *savestr();
extern void unget_char();
static char get_list();
ecode_e ecode = e_none;
entry *e;
int ch;
void skip_comments();
char cmd[MAX_COMMAND];
e = (entry *) calloc(sizeof(entry), sizeof(char));
Debug(DPARS, ("load_entry()...about to eat comments\n"))
skip_comments(file);
ch = get_char(file);
/* ch is now the first useful character of a useful line.
* it may be an @special or it may be the first character
* of a list of minutes.
*/
if (ch == '@')
{
/* all of these should be flagged and load-limited; i.e.,
* instead of @hourly meaning "0 * * * *" it should mean
* "close to the front of every hour but not 'til the
* system load is low". Problems are: how do you know
* what "low" means? (save me from /etc/crond.conf!) and:
* how to guarantee low variance (how low is low?), which
* means how to we run roughly every hour -- seems like
* we need to keep a history or let the first hour set
* the schedule, which means we aren't load-limited
* anymore. too much for my overloaded brain. (vix, jan90)
* HINT
*/
ch = get_string(cmd, MAX_COMMAND, file, " \t\n");
if (!strcmp("reboot", cmd)) {
e->flags |= WHEN_REBOOT;
} else if (!strcmp("yearly", cmd) || !strcmp("annually", cmd)){
bit_set(e->minute, 0);
bit_set(e->hour, 0);
bit_set(e->dom, 0);
bit_set(e->month, 0);
bit_nset(e->dow, 0, (LAST_DOW-FIRST_DOW+1));
} else if (!strcmp("monthly", cmd)) {
bit_set(e->minute, 0);
bit_set(e->hour, 0);
bit_set(e->dom, 0);
bit_nset(e->month, 0, (LAST_MONTH-FIRST_MONTH+1));
bit_nset(e->dow, 0, (LAST_DOW-FIRST_DOW+1));
} else if (!strcmp("weekly", cmd)) {
bit_set(e->minute, 0);
bit_set(e->hour, 0);
bit_nset(e->dom, 0, (LAST_DOM-FIRST_DOM+1));
bit_nset(e->month, 0, (LAST_MONTH-FIRST_MONTH+1));
bit_set(e->dow, 0);
} else if (!strcmp("daily", cmd) || !strcmp("midnight", cmd)) {
bit_set(e->minute, 0);
bit_set(e->hour, 0);
bit_nset(e->dom, 0, (LAST_DOM-FIRST_DOM+1));
bit_nset(e->month, 0, (LAST_MONTH-FIRST_MONTH+1));
bit_nset(e->dow, 0, (LAST_DOW-FIRST_DOW+1));
} else if (!strcmp("hourly", cmd)) {
bit_set(e->minute, 0);
bit_set(e->hour, (LAST_HOUR-FIRST_HOUR+1));
bit_nset(e->dom, 0, (LAST_DOM-FIRST_DOM+1));
bit_nset(e->month, 0, (LAST_MONTH-FIRST_MONTH+1));
bit_nset(e->dow, 0, (LAST_DOW-FIRST_DOW+1));
} else {
ecode = e_timespec;
goto eof;
}
}
else
{
Debug(DPARS, ("load_entry()...about to parse numerics\n"))
ch = get_list(e->minute, FIRST_MINUTE, LAST_MINUTE,
PPC_NULL, ch, file);
if (ch == EOF)
{
ecode = e_minute;
goto eof;
}
/* hours
*/
ch = get_list(e->hour, FIRST_HOUR, LAST_HOUR,
PPC_NULL, ch, file);
if (ch == EOF)
{
ecode = e_hour;
goto eof;
}
/* DOM (days of month)
*/
if (ch == '*') e->flags |= DOM_STAR;
ch = get_list(e->dom, FIRST_DOM, LAST_DOM, PPC_NULL, ch, file);
if (ch == EOF)
{
ecode = e_dom;
goto eof;
}
/* month
*/
ch = get_list(e->month, FIRST_MONTH, LAST_MONTH,
MonthNames, ch, file);
if (ch == EOF)
{
ecode = e_month;
goto eof;
}
/* DOW (days of week)
*/
if (ch == '*') e->flags |= DOW_STAR;
ch = get_list(e->dow, FIRST_DOW, LAST_DOW,
DowNames, ch, file);
if (ch == EOF)
{
ecode = e_dow;
goto eof;
}
}
/* make sundays equivilent */
if (bit_test(e->dow, 0) || bit_test(e->dow, 7))
{
bit_set(e->dow, 0);
bit_set(e->dow, 7);
}
Debug(DPARS, ("load_entry()...about to parse command\n"))
/* ch is first character of a command. everything up to the next
* \n or EOF is part of the command... too bad we don't know in
* advance how long it will be, since we need to malloc a string
* for it... so, we limit it to MAX_COMMAND
*/
unget_char(ch, file);
ch = get_string(cmd, MAX_COMMAND, file, "\n");
/* a file without a \n before the EOF is rude, so we'll complain...
*/
if (ch == EOF)
{
ecode = e_cmd;
goto eof;
}
/* got the command in the 'cmd' string; save it in *e.
*/
e->cmd = savestr(cmd);
Debug(DPARS, ("load_entry()...returning successfully\n"))
/* success, fini, return pointer to the entry we just created...
*/
return e;
eof: /* if we want to return EOF, we have to jump down here and
* free the entry we've been building.
*
* now, in some cases, a parse routine will have returned EOF to
* indicate an error, but the file is not actually done. since, in
* that case, we only want to skip the line with the error on it,
* we'll do that here.
*
* many, including the author, see what's below as evil programming
* practice: since I didn't want to change the structure of this
* whole function to support this error recovery, I recurse. Cursed!
* (At least it's tail-recursion, as if it matters in C - vix/8feb88)
* I'm seriously considering using (another) GOTO... argh!
* (this does not get less disgusting over time. vix/15nov88)
*/
(void) free(e);
if (feof(file))
return NULL;
if (error_func)
(*error_func)(ecodes[(int)ecode]);
do {ch = get_char(file);}
while (ch != EOF && ch != '\n');
if (ch == EOF)
return NULL;
return load_entry(file, error_func);
}
static char
get_list(bits, low, high, names, ch, file)
bitstr_t *bits; /* one bit per flag, default=FALSE */
int low, high; /* bounds, impl. offset for bitstr */
char *names[]; /* NULL or *[] of names for these elements */
int ch; /* current character being processed */
FILE *file; /* file being read */
{
static char get_range();
register int done;
/* we know that we point to a non-blank character here;
* must do a Skip_Blanks before we exit, so that the
* next call (or the code that picks up the cmd) can
* assume the same thing.
*/
Debug(DPARS|DEXT, ("get_list()...entered\n"))
/* list = "*" | range {"," range}
*/
if (ch == '*')
{
/* '*' means 'all elements'.
*/
bit_nset(bits, 0, (high-low+1));
goto exit;
}
/* clear the bit string, since the default is 'off'.
*/
bit_nclear(bits, 0, (high-low+1));
/* process all ranges
*/
done = FALSE;
while (!done)
{
ch = get_range(bits, low, high, names, ch, file);
if (ch == ',')
ch = get_char(file);
else
done = TRUE;
}
exit: /* exiting. skip to some blanks, then skip over the blanks.
*/
Skip_Nonblanks(ch, file)
Skip_Blanks(ch, file)
Debug(DPARS|DEXT, ("get_list()...exiting w/ %02x\n", ch))
return ch;
}
static char
get_range(bits, low, high, names, ch, file)
bitstr_t *bits; /* one bit per flag, default=FALSE */
int low, high; /* bounds, impl. offset for bitstr */
char *names[]; /* NULL or names of elements */
int ch; /* current character being processed */
FILE *file; /* file being read */
{
/* range = number | number "-" number [ "/" number ]
*/
static int set_element();
static char get_number();
register int i;
auto int num1, num2, num3;
Debug(DPARS|DEXT, ("get_range()...entering, exit won't show\n"))
if (EOF == (ch = get_number(&num1, low, names, ch, file)))
return EOF;
if (ch != '-')
{
/* not a range, it's a single number.
*/
if (EOF == set_element(bits, low, high, num1))
return EOF;
}
else
{
/* eat the dash
*/
ch = get_char(file);
if (ch == EOF)
return EOF;
/* get the number following the dash
*/
ch = get_number(&num2, low, names, ch, file);
if (ch == EOF)
return EOF;
/* check for step size
*/
if (ch == '/')
{
/* eat the slash
*/
ch = get_char(file);
if (ch == EOF)
return EOF;
/* get the step size -- note: we don't pass the
* names here, because the number is not an
* element id, it's a step size. 'low' is
* sent as a 0 since there is no offset either.
*/
ch = get_number(&num3, 0, PPC_NULL, ch, file);
if (ch == EOF)
return EOF;
}
else
{
/* no step. default==1.
*/
num3 = 1;
}
/* range. set all elements from num1 to num2, stepping
* by num3. (the step is a downward-compatible extension
* proposed conceptually by bob@acornrc, syntactically
* designed then implmented by paul vixie).
*/
for (i = num1; i <= num2; i += num3)
if (EOF == set_element(bits, low, high, i))
return EOF;
}
return ch;
}
static char
get_number(numptr, low, names, ch, file)
int *numptr;
int low;
char *names[];
char ch;
FILE *file;
{
char temp[MAX_TEMPSTR], *pc;
int len, i, all_digits;
/* collect alphanumerics into our fixed-size temp array
*/
pc = temp;
len = 0;
all_digits = TRUE;
while (isalnum(ch))
{
if (++len >= MAX_TEMPSTR)
return EOF;
*pc++ = ch;
if (!isdigit(ch))
all_digits = FALSE;
ch = get_char(file);
}
*pc = '\0';
/* try to find the name in the name list
*/
if (names)
for (i = 0; names[i] != NULL; i++)
{
Debug(DPARS|DEXT,
("get_num, compare(%s,%s)\n", names[i], temp))
if (!nocase_strcmp(names[i], temp))
{
*numptr = i+low;
return ch;
}
}
/* no name list specified, or there is one and our string isn't
* in it. either way: if it's all digits, use its magnitude.
* otherwise, it's an error.
*/
if (all_digits)
{
*numptr = atoi(temp);
return ch;
}
return EOF;
}
static int
set_element(bits, low, high, number)
bitstr_t *bits; /* one bit per flag, default=FALSE */
int low;
int high;
int number;
{
Debug(DPARS|DEXT, ("set_element(?,%d,%d,%d)\n", low, high, number))
if (number < low || number > high)
return EOF;
Debug(DPARS|DEXT, ("bit_set(%x,%d)\n",bits,(number-low)))
bit_set(bits, (number-low));
Debug(DPARS|DEXT, ("bit_set succeeded\n"))
return OK;
}
Continuous source code history from original PDP-7 UNIX to FreeBSD 2, the first fully unencumbered FreeBSD release.