[26697] in Source-Commits
/svn/athena r25696 - in trunk/athena/bin/desync: . debian
daemon@ATHENA.MIT.EDU (Jonathan D Reed)
Fri Aug 3 23:32:56 2012
Date: Fri, 3 Aug 2012 23:32:02 -0400
From: Jonathan D Reed <jdreed@MIT.EDU>
Message-Id: <201208040332.q743W2VX006187@drugstore.mit.edu>
To: source-commits@MIT.EDU
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit
Author: jdreed
Date: 2012-08-03 23:32:02 -0400 (Fri, 03 Aug 2012)
New Revision: 25696
Modified:
trunk/athena/bin/desync/debian/changelog
trunk/athena/bin/desync/desync.1
trunk/athena/bin/desync/desync.c
Log:
In desync:
* Add -c option to generate crontab output (Trac: #1173)
Modified: trunk/athena/bin/desync/debian/changelog
===================================================================
--- trunk/athena/bin/desync/debian/changelog 2012-08-03 23:54:13 UTC (rev 25695)
+++ trunk/athena/bin/desync/debian/changelog 2012-08-04 03:32:02 UTC (rev 25696)
@@ -1,8 +1,9 @@
-debathena-desync (10.0.0-0debathena3) UNRELEASED; urgency=low
+debathena-desync (10.1-0debathena1) unstable; urgency=low
* Bump debian/compat to 6
+ * Add -c option to generate crontab output (Trac: #1173)
- -- Jonathan Reed <jdreed@mit.edu> Sun, 01 Jul 2012 12:21:32 -0400
+ -- Jonathan Reed <jdreed@mit.edu> Fri, 03 Aug 2012 23:26:43 -0400
debathena-desync (10.0.0-0debathena2) unstable; urgency=low
Modified: trunk/athena/bin/desync/desync.1
===================================================================
--- trunk/athena/bin/desync/desync.1 2012-08-03 23:54:13 UTC (rev 25695)
+++ trunk/athena/bin/desync/desync.1 2012-08-04 03:32:02 UTC (rev 25696)
@@ -14,7 +14,7 @@
.\" this software for any purpose. It is provided "as is"
.\" without express or implied warranty.
.\"
-.TH DESYNC 1 "5 March 1997"
+.TH DESYNC 1 "3 August 2012"
.SH NAME
desync \- desynchronize timed jobs on networks
.SH SYNOPSIS
@@ -22,6 +22,11 @@
[
.B \-t
timefile ] [ range ]
+
+.B desync
+[
+.B \-c
+hours ] [ range ] [ other arguments ]
.SH DESCRIPTION
.I desync
is a tool which sleeps a random (hostname seeded) period of time (up
@@ -83,7 +88,7 @@
.I timefile
exists and the current time is equal to or greater than the time value
listed in
-.IR timefile ,
+q.IR timefile ,
then
.I desync
unlinks
@@ -99,6 +104,28 @@
fi
.fi
+.TP 8
+.B \-c hours
+This option changes the behavior of
+.I desync
+and causes it to generate output suitable for use in a crontab file.
+This is useful on modern Linux distributions, where sleeping for
+extended periods inside a cron job can confuse power management software
+or packages such as ConsoleKit, and running a cron job every 5 minutes
+to see if desync thinks it is "time to run" is undesirable. Since
+desync will generate the same value each time on the same machine, it is
+fine to generate crontab files in a package's post-install script, for
+example. In this mode, desync will output the crontab fields and then
+any additional arguments you supply. So to generate a crontab with a
+randomized job, one might do something like this:
+
+.nf
+ for i in 2 4 8 14 20; do
+ desync -c $i 120 root /etc/athena/update_ws >> /etc/cron.d/update
+ done
+.fi
+
+
.SH SEE ALSO
cron(8)
.SH AUTHOR
@@ -106,4 +133,6 @@
.br
Greg Hudson, MIT Information Systems
.br
-Copyright (c) 1995, 1996, 1997, Massachusetts Institute of Technology
+Debathena Project
+.br
+Copyright (c) 1995, 1996, 1997, 2012 Massachusetts Institute of Technology
Modified: trunk/athena/bin/desync/desync.c
===================================================================
--- trunk/athena/bin/desync/desync.c 2012-08-03 23:54:13 UTC (rev 25695)
+++ trunk/athena/bin/desync/desync.c 2012-08-04 03:32:02 UTC (rev 25696)
@@ -34,6 +34,7 @@
#include <errno.h>
#include <unistd.h>
#include <time.h>
+#include <limits.h>
extern int optind;
extern char *optarg;
@@ -46,7 +47,7 @@
int main(int argc, char **argv)
{
- const char *timefile = NULL, *hostname = NULL;
+ const char *timefile = NULL, *hostname = NULL, *crontabhour = NULL;
char buf[128];
int range, interval, c, noop = 0;
unsigned long tval;
@@ -57,7 +58,7 @@
progname = argv[0];
/* Parse command-line flags. */
- while ((c = getopt(argc, argv, "h:nt:")) != -1)
+ while ((c = getopt(argc, argv, "h:nc:t:")) != -1)
{
switch (c) {
case 'h':
@@ -66,6 +67,9 @@
case 'n':
noop = 1;
break;
+ case 'c':
+ crontabhour = optarg;
+ break;
case 't':
timefile = optarg;
break;
@@ -75,10 +79,24 @@
}
}
+ if (crontabhour && ((timefile != NULL) || (noop == 1))) {
+ usage();
+ return 2;
+ }
/* Get the time interval from the remaining argument, if there is one. */
argc -= optind;
argv += optind;
- range = (argc == 1) ? atoi(argv[0]) : 3600;
+ if ((argc > 1) && ! crontabhour) {
+ usage();
+ return 2;
+ }
+ if (argc >= 1) {
+ range = atoi(argv[0]);
+ argc -= 1;
+ argv += 1;
+ } else {
+ range = 3600;
+ }
if (range == 0)
{
fprintf(stderr, "%s: Invalid range value\n", progname);
@@ -155,6 +173,35 @@
return 1;
}
}
+ else if (crontabhour)
+ {
+ char *endptr;
+ int mins, hours = 0;
+ int j;
+ errno = 0;
+ hours = strtol(crontabhour, &endptr, 10);
+ if ((errno == ERANGE && (hours == LONG_MAX || hours == LONG_MIN))
+ || (errno != 0 && hours == 0)
+ || (endptr == crontabhour))
+ {
+ fprintf(stderr, "%s: Could not convert %s to integer\n", progname,
+ crontabhour);
+ return 1;
+ }
+ if ((hours > 23) || (hours < 0 ))
+ {
+ fprintf(stderr,
+ "%s: in crontab mode, hours must be between 0 and 23\n",
+ progname);
+ return 1;
+ }
+ mins = interval % 60;
+ hours = (hours + (interval / 60)) % 24;
+ printf("%d %d * * *", mins, hours);
+ for (j = 0; j < argc; j++)
+ printf(" %s", argv[j]);
+ printf("\n");
+ }
else if (noop)
printf("%lu\n", (unsigned long) interval);
else
@@ -187,6 +234,6 @@
static void usage()
{
fprintf(stderr,
- "Usage: %s [-h name] [-n] [-t timefile] [range]\n",
- progname);
+ "Usage: %s [-h name] [-n] [-t timefile] [range]\n %s [-c hour] [range] [crontab arguments]\n",
+ progname, progname);
}
