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diff --git a/upstream/mageia-cauldron/man5/crontab.5 b/upstream/mageia-cauldron/man5/crontab.5 new file mode 100644 index 00000000..5d898627 --- /dev/null +++ b/upstream/mageia-cauldron/man5/crontab.5 @@ -0,0 +1,357 @@ +.\"/* Copyright 1988,1990,1993,1994 by Paul Vixie +.\" * All rights reserved +.\" */ +.\" +.\" Copyright (c) 2004 by Internet Systems Consortium, Inc. ("ISC") +.\" Copyright (c) 1997,2000 by Internet Software Consortium, Inc. +.\" +.\" Permission to use, copy, modify, and distribute this software for any +.\" purpose with or without fee is hereby granted, provided that the above +.\" copyright notice and this permission notice appear in all copies. +.\" +.\" THE SOFTWARE IS PROVIDED "AS IS" AND ISC DISCLAIMS ALL WARRANTIES +.\" WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF +.\" MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL ISC BE LIABLE FOR +.\" ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES +.\" WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN +.\" ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT +.\" OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. +.\" +.\" $Id: crontab.5,v 1.6 2004/01/23 19:03:33 vixie Exp $ +.\" +.TH CRONTAB 5 2012-11-22 "cronie" "File Formats" +.SH NAME +crontab \- files used to schedule the execution of programs +.SH DESCRIPTION +A +.I crontab +file contains instructions for the +.BR cron (8) +daemon in the following simplified manner: "run this command at this time +on this date". Each user can define their own crontab. Commands defined +in any given crontab are executed under the user who owns that particular +crontab. Uucp and News usually have their own crontabs, eliminating the +need for explicitly running +.BR su (1) +as part of a cron command. +.PP +Blank lines, leading spaces, and tabs are ignored. Lines whose first +non-white space character is a pound-sign (#) are comments, and are not +processed. Note that comments are not allowed on the same line as cron +commands, since they are considered a part of the command. Similarly, +comments are not allowed on the same line as environment variable +settings. +.PP +An active line in a crontab is either an environment setting or a cron +command. An environment setting is of the form: +.PP + name = value +.PP +where the white spaces around the equal-sign (=) are optional, and any +subsequent non-leading white spaces in +.I value +is a part of the value assigned to +.IR name . +The +.I value +string may be placed in quotes (single or double, but matching) to +preserve leading or trailing white spaces. +.PP +Several environment variables are set up automatically by the +.BR cron (8) +daemon. +.I SHELL +is set to /bin/sh, and +.I LOGNAME +and +.I HOME +are set from the /etc/passwd line of the crontab\'s owner. +.I HOME +and +.I SHELL +can be overridden by settings in the crontab; LOGNAME can not. +.PP +(Note: the +.I LOGNAME +variable is sometimes called +.I USER +on BSD systems and is also automatically set). +.PP +In addition to +.IR LOGNAME , +.IR HOME , +and +.IR SHELL , +.BR cron (8) +looks at the +.I MAILTO +variable if a mail needs to be send as a result of running any commands +in that particular crontab. If +.I MAILTO +is defined (and non-empty), mail is sent to the specified address. If +.I MAILTO +is defined but empty +.RI ( MAILTO="" ), +no mail is sent. Otherwise, mail is sent to the owner of the crontab. +This option is useful if you decide to use /bin/mail instead of +/usr/lib/sendmail as your mailer. Note that /bin/mail does not provide +aliasing and UUCP usually does not read its mail. If +.I MAILFROM +is defined (and non-empty), it is used as the envelope sender address, +otherwise, ``root'' is used. +.PP +(Note: Both +.I MAILFROM +and +.I MAILTO +variables are expanded, so setting them as in the following example works as expected: MAILFROM=cron-$USER@cron.com ($USER is replaced by the system user) ) +.PP +By default, cron sends a mail using the 'Content-Type:' header +of 'text/plain' with the 'charset=' parameter set to the 'charmap/codeset' +of the locale in which +.BR crond (8) +is started up, i.e., either the default system locale, if no LC_* +environment variables are set, or the locale specified by the LC_* +environment variables (see +.BR locale (7)). +Different character encodings can be used for mailing cron job outputs by +setting the +.I CONTENT_TYPE +and +.I CONTENT_TRANSFER_ENCODING +variables in a crontab to the correct values of the mail headers of those +names. +.PP +The +.I CRON_TZ +variable specifies the time zone specific for the cron table. The user +should enter a time according to the specified time zone into the table. +The time used for writing into a log file is taken from the local time +zone, where the daemon is running. +.PP +The +.I MLS_LEVEL +environment variable provides support for multiple per-job SELinux +security contexts in the same crontab. By default, cron jobs execute +with the default SELinux security context of the user that created the +crontab file. When using multiple security levels and roles, this may +not be sufficient, because the same user may be running in different +roles or in different security levels. For more information about roles +and SELinux MLS/MCS, see +.BR selinux (8) +and the crontab example mentioned later on in this text. You can set the +.I MLS_LEVEL +variable to the SELinux security context string specifying the particular +SELinux security context in which you want jobs to be run. +.B crond +will then set the execution context of those jobs that meet the +specifications of the particular security context. For more information, +see +.BR crontab (1)\ -s\ option. +.PP +The +.I RANDOM_DELAY +variable allows delaying job startups by random amount of minutes with +upper limit specified by the variable. The random scaling factor is +determined during the cron daemon startup so it remains constant for +the whole run time of the daemon. +.PP +The format of a cron command is similar to the V7 standard, with a number +of upward-compatible extensions. Each line has five time-and-date fields +followed by a +.BR user name +(if this is the +.BR system +crontab file), and followed by a command. Commands are executed by +.BR cron (8) +when the 'minute', 'hour', and 'month of the year' fields match the +current time, +.I and +at least one of the two 'day' fields ('day of month', or 'day of week') +match the current time (see "Note" below). +.PP +Note that this means that non-existent times, such as the "missing hours" +during the daylight savings time conversion, will never match, causing +jobs scheduled during the "missing times" not to be run. Similarly, +times that occur more than once (again, during the daylight savings time +conversion) will cause matching jobs to be run twice. +.PP +.BR cron (8) +examines cron entries every minute. +.PP +The time and date fields are: +.IP +.ta 1.5i +field allowed values +.br +----- -------------- +.br +minute 0-59 +.br +hour 0-23 +.br +day of month 1-31 +.br +month 1-12 (or names, see below) +.br +day of week 0-7 (0 or 7 is Sunday, or use names) +.br +.PP +A field may contain an asterisk (*), which always stands for +"first\-last". +.PP +Ranges of numbers are allowed. Ranges are two numbers separated with a +hyphen. The specified range is inclusive. For example, 8-11 for +an 'hours' entry specifies execution at hours 8, 9, 10, and 11. The first +number must be less than or equal to the second one. +.PP +Randomization of the execution time within a range can be used. +A random number within a range specified as two numbers separated with +a tilde is picked. The specified range is inclusive. +For example, 6~15 for a 'minutes' entry picks a random minute +within 6 to 15 range. The random number is picked when crontab file is parsed. +The first number must be less than or equal to the second one. You might omit +one or both of the numbers specifying the range. For example, ~ for a 'minutes' +entry picks a random minute within 0 to 59 range. +.PP +Lists are allowed. A list is a set of numbers (or ranges) separated by +commas. Examples: "1,2,5,9", "0-4,8-12". +.PP +Step values can be used in conjunction with ranges. Following a range +with "/<number>" specifies skips of the number's value through the range. +For example, "0-23/2" can be used in the 'hours' field to specify command +execution for every other hour (the alternative in the V7 standard is +"0,\:2,\:4,\:6,\:8,\:10,\:12,\:14,\:16,\:18,\:20,\:22"). Step values are +also permitted after an asterisk, so if specifying a job to be run every +two hours, you can use "*/2". +.PP +Names can also be used for the 'month' and 'day of week' fields. Use the +first three letters of the particular day or month (case does not +matter). Ranges and lists of names are allowed. Examples: "mon,wed,fri", +"jan-mar". +.PP +If the UID of the owner is 0 (root), the first character of a crontab +entry can be "-" character. This will prevent cron from writing a syslog +message about the command being executed. +.PP +The "sixth" field (the rest of the line) specifies the command to be run. +The entire command portion of the line, up to a newline or a "%" +character, will be executed by /bin/sh or by the shell specified in the +SHELL variable of the cronfile. A "%" character in the command, unless +escaped with a backslash (\\), will be changed into newline characters, +and all data after the first % will be sent to the command as standard +input. +.PP +Note: The day of a command's execution can be specified in the following +two fields \(em 'day of month', and 'day of week'. If both fields are +restricted (i.e., do not contain the "*" character), the command will be +run when +.I either +field matches the current time. For example, +.br +"30 4 1,15 * 5" would cause a command to be run at 4:30 am on the 1st and +15th of each month, plus every Friday. +.PP +A crontab file syntax can be tested before an install using the -T option. See +.BR crontab (1) +for details. +.SH EXAMPLE CRON FILE +.nf +# use /bin/sh to run commands, no matter what /etc/passwd says +SHELL=/bin/sh +# mail any output to `paul', no matter whose crontab this is +MAILTO=paul +# +CRON_TZ=Japan +# run five minutes after midnight, every day +5 0 * * * $HOME/bin/daily.job >> $HOME/tmp/out 2>&1 +# run at 2:15pm on the first of every month -- output mailed to paul +15 14 1 * * $HOME/bin/monthly +# run at 10 pm on weekdays, annoy Joe +0 22 * * 1-5 mail -s "It's 10pm" joe%Joe,%%Where are your kids?% +23 0-23/2 * * * echo "run 23 minutes after midn, 2am, 4am ..., everyday" +5 4 * * sun echo "run at 5 after 4 every sunday" +.fi +.SH Jobs in /etc/cron.d/ +The jobs in +.I cron.d +and +.I /etc/crontab +are system jobs, which are used usually for more than one user, thus, +additionally the username is needed. MAILTO on the first line is +optional. +.SH EXAMPLE OF A JOB IN /etc/cron.d/job +.nf +#login as root +#create job with preferred editor (e.g. vim) +MAILTO=root +* * * * * root touch /tmp/file +.fi +.SH SELinux with multi level security (MLS) +In a crontab, it is important to specify a security level by +.I crontab \-s +or specifying the required level on the first line of the crontab. Each +level is specified in +.IR /etc/selinux/targeted/seusers . +When using crontab in the MLS mode, it is especially important to: +.br +- check/change the actual role, +.br +- set correct +.I role for +.IR directory , +which is used for input/output. +.SH EXAMPLE FOR SELINUX MLS +.nf +# login as root +newrole -r sysadm_r +mkdir /tmp/SystemHigh +chcon -l SystemHigh /tmp/SystemHigh +crontab -e +# write in crontab file +MLS_LEVEL=SystemHigh +0-59 * * * * id -Z > /tmp/SystemHigh/crontest +.fi +.SH FILES +.I /etc/crontab +main system crontab file. +.I /var/spool/cron/ +a directory for storing crontabs defined by users. +.I /etc/cron.d/ +a directory for storing system crontabs. +.SH "SEE ALSO" +.BR cron (8), +.BR crontab (1) +.SH EXTENSIONS +These special time specification "nicknames" which replace the 5 initial +time and date fields, and are prefixed with the '@' character, are +supported: +.PP +.nf +@reboot : Run once after reboot. +@yearly : Run once a year, ie. "0 0 1 1 *". +@annually : Run once a year, ie. "0 0 1 1 *". +@monthly : Run once a month, ie. "0 0 1 * *". +@weekly : Run once a week, ie. "0 0 * * 0". +@daily : Run once a day, ie. "0 0 * * *". +@hourly : Run once an hour, ie. "0 * * * *". +.fi +.SH CAVEATS +.BR crontab +files have to be regular files or symlinks to regular files, they must +not be executable or writable for anyone else but the owner. This +requirement can be overridden by using the +.B \-p +option on the crond command line. If inotify support is in use, changes +in the symlinked crontabs are not automatically noticed by the cron +daemon. The cron daemon must receive a SIGHUP signal to reload the +crontabs. This is a limitation of the inotify API. +.PP +cron requires that each entry in a crontab end in a newline character. If the +last entry in a crontab is missing a newline (i.e.\& terminated by EOF), +cron will consider the crontab (at least partially) broken. +A warning will be written to syslog. +.SH AUTHOR +.MT vixie@isc.org +Paul Vixie +.ME |