AT(1)               UNIX Programmer's Manual                AT(1)

NAME
     at - execute commands at a later time

SYNTAX
     at [ -m ] time [ day ] [ file ]

DESCRIPTION
     _A_t squirrels away a copy of the named _f_i_l_e (standard input
     default) to be used as input to _s_h(1) or _c_s_h(1) at a speci-
     fied later time.  A csh script must have a '#' as the first
     character.  If no file is given input is taken from the
     standard input and the shell is determined by the SHELL
     environment variable.  A _c_d(1) command to the current direc-
     tory is inserted at the beginning, followed by assignments
     to all environment variables except TERMCAP.  In _c_s_h, the
     users .cshrc file is then run. When the script is run, it
     uses the user and group ID of the creator of the copy file.
     Mail is sent to that user stating when the file ran and giv-
     ing any output on stdout or stdin.  The -m flag causes no
     mail to be sent.

     The _t_i_m_e is 1 to 4 digits, with an optional following `A',
     `P', `N' or `M' for AM, PM, noon or midnight.  The letters
     may be upper or lower case. One and two digit numbers are
     taken to be hours, three and four digits to be hours and
     minutes.  If no letters follow the digits, a 24 hour clock
     time is understood.

     The optional _d_a_y is either (1) a month name followed by a
     day number, or (2) a day of the week; if the word `week'
     follows invocation is moved seven days further off.  If no
     day is specified, today is assumed if the time is after the
     current time.  If the time is before the current time,
     tomorrow is assumed.  Names of months and days may be recog-
     nizably truncated.  Examples of legitimate commands are:

          at 8am jan 24
          at 1530 fr week

     _A_t scripts are executed by periodic execution of the command
     /_u_s_r/_l_i_b/_a_t_r_u_n from _c_r_o_n(8) typically every 5 minutes.

FILES
     /usr/spool/at/yy.ddd.hhhh.uu
                     activity to be performed at hour _h_h_h_h of
                     year day _d_d_d of year _y_y.  _u_u is a unique
                     number.

     /usr/spool/at/lasttimedone
                     contains _h_h_h_h for last hour of atrun exe-
                     cuted.

Printed 7/22/83                                                 1

AT(1)               UNIX Programmer's Manual                AT(1)

     /usr/spool/at/past
                     directory of activities now in progress

     /usr/lib/atrun  program that executes activities that are
                     due

     _p_w_d(1)          To find current directory

     _M_a_i_l(1)         To mail output of script

SEE ALSO
     calendar(1), cron(8)

DIAGNOSTICS
     Complains about various syntax errors and times out of
     range.
     If the process dies during execution look in
     /_u_s_r/_s_p_o_o_l/_a_t/_p_a_s_t for the executing file.  The mail file is
     the same name as the executing file except the first number
     has been changed to 'M'.

BUGS
     Scripts beginning with a '#' are assumed to be csh scripts;
     this may be inappropriate for scripts that start with
     "#!/bin/sh".

AUTHOR
     UNIX Version 7.  Modified for csh and mail by Peter L. Ward,
     U.S. Geological Survey, Menlo Park, California.

Printed 7/22/83                                                 2