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AT(1)			    UNIX Reference Manual			 AT(1)

N\bNA\bAM\bME\bE
     a\bat\bt - schedule execution of commands `at' a given time

S\bSY\bYN\bNO\bOP\bPS\bSI\bIS\bS
     a\bat\bt [-\b-c\bc] [-\b-s\bs] [-\b-m\bm] _\bt_\bi_\bm_\be [_\bd_\ba_\by] [_\bc_\bo_\bm_\bm_\ba_\bn_\bd__\bf_\bi_\bl_\be]

D\bDE\bES\bSC\bCR\bRI\bIP\bPT\bTI\bIO\bON\bN
     A\bAt\bt schedules execution of commands at the specified _\bt_\bi_\bm_\be.	The commands
     may be given to a\bat\bt via the _\bc_\bo_\bm_\bm_\ba_\bn_\bd__\bf_\bi_\bl_\be or accepted from the standard in-
     put.  A\bAt\bt 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:

     -\b-c\bc        _\bC_\bo_\bm_\bm_\ba_\bn_\bd__\bf_\bi_\bl_\be contains csh(1) commands.

     -\b-s\bs        _\bC_\bo_\bm_\bm_\ba_\bn_\bd__\bf_\bi_\bl_\be contains sh(1) commands.

     -\b-m\bm        Mail will be sent to the user after the job has been run. If
	       errors 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 _\bc_\bo_\bm_\bm_\ba_\bn_\bd__\bf_\bi_\bl_\be is not specified, a\bat\bt 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
     includes 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 c\bcd\bd command to the current directory and a u\bum\bma\bas\bsk\bk
     command to set the modes on any files created by the job.	Then a\bat\bt 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 _\bt_\bi_\bm_\be is either a 24 hour military time _\bh_\bh_\bm_\bm, where _\bh_\bh is hour and _\bm_\bm
     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 _\bd_\ba_\by of the week may be specified by the first two letters of its name.
     A week (7 days) may be specified by the argument _\bw_\be_\be_\bk.  If a month name
     is given, the following argument is expected to be the day (numeric).

E\bEN\bNV\bVI\bIR\bRO\bON\bNM\bME\bEN\bNT\bT
     If a shell is not specified, the current environment variable SHELL is
     used.

E\bEX\bXA\bAM\bMP\bPL\bLE\bES\bS
     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
		 completion or termination of the job.

     at -s -m 1200n week
		 Use sh(1), send mail upon completetion, start at noon
		 o'clock, one week from today.
     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).

E\bER\bRR\bRO\bOR\bRS\bS
     Errors must be collected via the -\b-m\bm option or by redirecting the standard
     output from inside the _\bc_\bo_\bm_\bm_\ba_\bn_\bd__\bf_\bi_\bl_\be.

F\bFI\bIL\bLE\bES\bS
     /_\bv_\ba_\br/_\bs_\bp_\bo_\bo_\bl/_\ba_\bt		   spooling area
     /_\bv_\ba_\br/_\bs_\bp_\bo_\bo_\bl/_\ba_\bt/_\by_\by._\bd_\bd_\bd._\bh_\bh_\bh_\bh.*   job file
     /_\bv_\ba_\br/_\bs_\bp_\bo_\bo_\bl/_\ba_\bt/_\bp_\ba_\bs_\bt            directory where jobs are executed from
     /_\bv_\ba_\br/_\bs_\bp_\bo_\bo_\bl/_\ba_\bt/_\bl_\ba_\bs_\bt_\bt_\bi_\bm_\be_\bd_\bo_\bn_\be    last time atrun was run
     /_\bv_\ba_\br/_\bl_\bi_\bb_\be_\bx_\be_\bc/_\ba_\bt_\br_\bu_\bn            executor (run by cron(8))


S\bSE\bEE\bE A\bAL\bLS\bSO\bO
     atq(1), atrm(1), calendar(1), cron(8) sleep(1),

D\bDI\bIA\bAG\bGN\bNO\bOS\bST\bTI\bIC\bCS\bS
     Complains about various syntax errors and times out of range.

H\bHI\bIS\bST\bTO\bOR\bRY\bY
     A\bAt\bt appeared in Version 7 AT&T UNIX.

B\bBU\bUG\bGS\bS
     The queueing mechanism /_\bu_\bs_\br/_\bl_\bi_\bb_\be_\bx_\be_\bc/_\ba_\bt_\br_\bu_\bn, is scheduled by cron(8).  Fre-
     quency with which cron(8) runs /_\bu_\bs_\br/_\bl_\bi_\bb_\be_\bx_\be_\bc/_\ba_\bt_\br_\bu_\bn is site dependent.  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
     a\bat\bt.

     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
     /_\bv_\ba_\br/_\bs_\bp_\bo_\bo_\bl/_\ba_\bt/_\bp_\ba_\bs_\bt.  This is usually due to a system crash, and requires
     that they be removed by hand.