[26723] in Source-Commits
/svn/athena r25710 - trunk/athena/bin/desync
daemon@ATHENA.MIT.EDU (Jonathan D Reed)
Tue Aug 7 19:57:09 2012
Date: Tue, 7 Aug 2012 19:57:06 -0400
From: Jonathan D Reed <jdreed@MIT.EDU>
Message-Id: <201208072357.q77Nv6lK001807@drugstore.mit.edu>
To: source-commits@MIT.EDU
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit
Author: jdreed
Date: 2012-08-07 19:57:06 -0400 (Tue, 07 Aug 2012)
New Revision: 25710
Modified:
trunk/athena/bin/desync/desync.1
trunk/athena/bin/desync/desync.c
Log:
Update usage and enforce limits in crontab mode
Modified: trunk/athena/bin/desync/desync.1
===================================================================
--- trunk/athena/bin/desync/desync.1 2012-08-07 19:58:58 UTC (rev 25709)
+++ trunk/athena/bin/desync/desync.1 2012-08-07 23:57:06 UTC (rev 25710)
@@ -24,7 +24,7 @@
timefile ] [ range ]
.B desync -c
-hours [ range ] [ other arguments ]
+hours [ range [ other arguments ] ]
.SH DESCRIPTION
.I desync
is a tool which sleeps a random (hostname seeded) period of time (up
@@ -44,7 +44,8 @@
.TP 8
.B range
This optional range specifies, in seconds, the maximum value for the
-randomly selected sleep time. The default value is 3600.
+randomly selected sleep time. The default value is 3600 (except in
+"crontab" mode, see below).
.TP 8
.B \-h name
Use
@@ -106,16 +107,20 @@
.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:
+and causes it to generate output suitable for use in a crontab file. It
+also changes the units of
+.I range
+to minutes (from seconds), changes the default value to 60 and enforces
+a maximum value of 1439. 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
Modified: trunk/athena/bin/desync/desync.c
===================================================================
--- trunk/athena/bin/desync/desync.c 2012-08-07 19:58:58 UTC (rev 25709)
+++ trunk/athena/bin/desync/desync.c 2012-08-07 23:57:06 UTC (rev 25710)
@@ -95,9 +95,10 @@
argc -= 1;
argv += 1;
} else {
- range = 3600;
+ range = crontabhour == NULL ? 3600 : 60;
}
- if (range == 0)
+ if ((range == 0) ||
+ (crontabhour && (range >= 1440)))
{
fprintf(stderr, "%s: Invalid range value\n", progname);
usage();
@@ -234,6 +235,6 @@
static void usage()
{
fprintf(stderr,
- "Usage: %s [-h name] [-n] [-t timefile] [range]\n %s -c hour [range] [crontab arguments]\n",
+ "Usage: %s [-h name] [-n] [-t timefile] [range]\n %s -c hour [range [crontab arguments]]\n",
progname, progname);
}
