crontab

crontab - Schedule jobs that are executed automatically on a regular basis.

 crontab(1)                                                       crontab(1) NAME      crontab - user job file scheduler SYNOPSIS      crontab [file]      crontab -e      crontab -l      crontab -r DESCRIPTION      The crontab command manages a crontab file for the user.  You can use      a crontab file to schedule jobs that are executed automatically by      cron (see cron(1M)) on a regular basis.  The command has four forms:           crontab [file]    Create or replace your crontab file by copying                             the specified file, or standard input if file                             is omitted or - is specified as file , into the                             crontab directory, /var/spool/cron/crontabs.                             The name of your crontab file in the crontab                             directory is the same as your effective user                             name.           crontab -e        Edit a copy of your crontab file, or create an                             empty file to edit if the crontab file does not                             exist. When editing is complete, the file will                             be copied into the crontab directory as your                             crontab file.           crontab -l        List your crontab file.           crontab -r        Remove your crontab file from the crontab                             directory.      The entries in a crontab file are lines of six fields each.  The      fields are separated by spaces or tabs.  The lines have the following      format:           minute  hour  monthday  month  weekday  command      The first five are integer patterns that specify when the sixth field,      command, should be executed.  They can have the following ranges of      values:           minute         The minute of the hour, 0-59           hour           The hour of the day, 0-23           monthday       The day of the month, 1-31           month          The month of the year, 1-12           weekday        The day of the week, 0-6, 0=Sunday      Each pattern can be either an asterisk (*), meaning all legal values,      or a list of elements separated by commas.  An element is either a      number in the ranges shown above, or two numbers in the range      separated by a hyphen (meaning an inclusive range).  Note that the      specification of days can be made in two fields: monthday and weekday.      If both are specified in an entry, they are cumulative.  For example,           0   0   1,15   *   1   command      runs command at midnight on the first and fifteenth of each month, as      well as every Monday.  To specify days in only one field, set the      other field to asterisk (*).  For example,           0   0   *   *   1   command      runs command only on Mondays.      The sixth field, command (the balance of a line including blanks in a      crontab file), is a string that is executed by the shell at the      specified times.  A percent character (%) in this field (unless      escaped by a backslash (\)) is translated to a newline character,      dividing the field into "lines".  Only the first "line" (up to a % or      end-of-line) of the command field is executed by the shell.  Any other      "lines" are made available to the command as standard input.      Blank lines and those whose first non-blank character is # will be      ignored.      cron invokes the command from the user's HOME directory with the POSIX      shell, (/usr/bin/sh).  It runs in the c queue (see queuedefs(4)).      cron supplies a default environment for every shell, defining:           HOME=user's-home-directory           LOGNAME=user's-login-id           PATH=/usr/bin:/usr/sbin:.           SHELL=/usr/bin/sh      Users who desire to have their .profile executed must explicitly do so      in the crontab entry or in a script called by the entry.      You can execute crontab if your name appears in the file      /var/adm/cron/cron.allow.  If that file does not exist, you can use      crontab if your name does not appear in the file      /var/adm/cron/cron.deny.  If only cron.deny exists and is empty, all      users can use crontab.  If neither file exists, only the root user can      use crontab.  The allow/deny files consist of one user name per line. EXTERNAL INFLUENCES    Environment Variables      LC_CTYPE determines the interpretation of text within file as single-      and/or multi-byte characters.      LC_MESSAGES determines the language in which messages are displayed.      If LC_CTYPE or LC_MESSAGES is not specified in the environment or is      set to the empty string, the value of LANG is used as a default for      each unspecified or empty variable.  If LANG is not specified or is      set to the empty string, a default of "C" (see lang(5)) is used      instead of LANG.      If any internationalization variable contains an invalid setting,      crontab behaves as if all internationalization variables are set to      "C".  See environ(5).  EDITOR determines the editor to be invoked when      -e option is specified. The default editor is vi.    International Code Set Support      Single-byte and multi-byte character code sets are supported. WARNINGS      Be sure to redirect the standard output and standard error from      commands.  If this is not done, any generated standard output or      standard error is mailed to the user. FILES      /var/adm/cron                 Main cron directory      /var/adm/cron/cron.allow      List of allowed users      /var/adm/cron/cron.deny       List of denied users      /var/adm/cron/log             Accounting information      /var/spool/cron/crontabs      Directory containing the crontab files SEE ALSO      sh(1), cron(1M), queuedefs(4). STANDARDS CONFORMANCE      crontab: SVID2, SVID3, XPG2, XPG3, XPG4