4.4BSD/usr/share/man/cat1/at.0

AT(1)                        BSD Reference Manual                        AT(1)

NNAAMMEE
     aatt - schedule execution of commands `at' a given time

SSYYNNOOPPSSIISS
     aatt [--cc] [--mm] [--ss] _t_i_m_e [_d_a_y] [_c_o_m_m_a_n_d___f_i_l_e]

DDEESSCCRRIIPPTTIIOONN
     AAtt schedules execution of commands at the specified _t_i_m_e. The commands
     may be given to aatt via the _c_o_m_m_a_n_d___f_i_l_e or accepted from the standard in-
     put.  AAtt will pass these commands to the appropriate shell at the re-
     quested time. While awaiting execution, the jobs reside in a spool direc-
     tory and may be examined by the atq(1) program.

     Options available:

     --cc      _C_o_m_m_a_n_d___f_i_l_e contains csh(1) commands.

     --ss      _C_o_m_m_a_n_d___f_i_l_e contains sh(1) commands.

     --mm      Mail will be sent to the user after the job has been run. If er-
             rors occur during execution of the job, then a copy of the error
             diagnostics will be sent to the user. If no errors occur, then a
             short message is sent informing the user that no errors occurred.

     If a _c_o_m_m_a_n_d___f_i_l_e is not specified, aatt prompts for commands from standard
     input until a `^D' is typed.

     The format of the spool file is as follows: a four line header that in-
     cludes the owner of the job, the name of the job, the shell used to run
     the job, and whether mail will be sent after the job is executed. The
     header is followed by a ccdd command to the current directory and a uummaasskk
     command to set the modes on any files created by the job.  AAtt copies all
     relevant environment variables to the spool file.  When the script is
     run, it uses the user and group ID of the creator of the spool file.

     The _t_i_m_e is either a 24 hour military time _h_h_m_m_, where _h_h is hour and _m_m
     is minutes, or the traditional 12 hour time with qualifying options:

                 am, a   am
                 pm, p   pm
                 n       noon
                 m       midnight

     The time can be abbreviated as shown below in EXAMPLES.

     A _d_a_y of the week may be specified by the first two letters of its name.
     A week (7 days) may be specified by the argument _w_e_e_k. If a month name is
     given, the following argument is expected to be the day (numeric).

EENNVVIIRROONNMMEENNTT
     If a shell is not specified, the current environment variable SHELL is
     used.

EEXXAAMMPPLLEESS
     at 10p  Execute at 10pm today, or tomorrow if 10pm has past. Use the
             shell found in the environment variable SHELL.

     at -c -m 1705 mo
             Execute at 5:05pm on Monday using csh(1) and send mail upon com-
             pletion or termination of the job.

     at -s -m 1200n week
             Execute at noon one week from today, using sh(1) and send mail

             upon completetion.

     at -s 8a apr 1
             Ideally this would be given late in March.  The commands would be
             run at 8 am on April first, using the sh(1).

EERRRROORRSS
     Errors must be collected via the --mm option or by redirecting the standard
     output from inside the _c_o_m_m_a_n_d___f_i_l_e_.

FFIILLEESS
     /var/spool/at                spooling area
     /var/spool/at/yy.ddd.hhhh.*  job file
     /var/spool/at/past           directory where jobs are executed from
     /var/spool/at/lasttimedone   last time atrun was run
     /var/libexec/atrun           executor (run by cron(8))

SSEEEE AALLSSOO
     atq(1),  atrm(1),  calendar(1),  cron(8) sleep(1),

DDIIAAGGNNOOSSTTIICCSS
     Complains about various syntax errors and times out of range.

BBUUGGSS
     The queueing mechanism _/_u_s_r_/_l_i_b_e_x_e_c_/_a_t_r_u_n, is scheduled by cron(8).  If
     it is run infrequently, a job may fall thru the cracks.

     There are known problems attempting to specify a time of 2400 hours to
     aatt.

     If the system crashes, mail is not sent to the user informing them that
     the job was not completed.

     Sometimes old spool files are not removed from the directory
     _/_v_a_r_/_s_p_o_o_l_/_a_t_/_p_a_s_t. This is usually due to a system crash, and requires
     that they be removed by hand.

HHIISSTTOORRYY
     An aatt command appeared in Version 7 AT&T UNIX.

4th Berkeley Distribution        June 29, 1993                               2