Commit | Line | Data |
---|---|---|
74506ec1 BJ |
1 | .TH AT 1 |
2 | .SH NAME | |
3 | at \- execute commands at a later time | |
4 | .SH SYNOPSIS | |
5 | .B at | |
6 | time | |
7 | [ | |
8 | day | |
9 | ] | |
10 | [ | |
11 | file | |
12 | ] | |
13 | .SH DESCRIPTION | |
14 | .I At | |
15 | squirrels away a copy of the named | |
16 | .I file | |
17 | (standard input default) | |
18 | to be used as input to | |
19 | .IR sh (1) | |
20 | at a specified later time. | |
21 | A | |
22 | .IR cd (1) | |
23 | command to the current directory is inserted | |
24 | at the beginning, | |
25 | followed by assignments to all environment variables. | |
26 | When the script is run, it uses the user and group ID | |
27 | of the creator of the copy file. | |
28 | .PP | |
29 | The | |
30 | .I time | |
31 | is 1 to 4 digits, with an optional following | |
32 | `A', `P', `N' or `M' for | |
33 | AM, PM, noon or midnight. | |
34 | One and two digit numbers are taken to be hours, three and four digits | |
35 | to be hours and minutes. | |
36 | If no letters follow the digits, a 24 hour clock time is understood. | |
37 | .PP | |
38 | The optional | |
39 | .I day | |
40 | is either | |
41 | (1) a month name followed by a day number, | |
42 | or | |
43 | (2) a day of the week; if the word `week' follows | |
44 | invocation is moved seven days further off. | |
45 | Names of months and days may be recognizably truncated. | |
46 | Examples of legitimate commands are | |
47 | .IP | |
48 | at 8am jan 24 | |
49 | .br | |
50 | at 1530 fr week | |
51 | .PP | |
52 | .I At | |
53 | programs are executed by periodic execution | |
54 | of the command | |
55 | .I /usr/lib/atrun | |
56 | from | |
57 | .IR cron (1m). | |
58 | The granularity of | |
59 | .I at | |
60 | depends upon how often | |
61 | .I atrun | |
62 | is executed. | |
63 | .PP | |
64 | Standard output or error output is lost unless redirected. | |
65 | .SH FILES | |
66 | /usr/spool/at/yy.ddd.hhhh.uu | |
67 | .br | |
68 | activity to be performed at hour | |
69 | .I hhhh | |
70 | of year day | |
71 | .I ddd | |
72 | of year | |
73 | .IR yy . | |
74 | .I uu | |
75 | is a unique number. | |
76 | .br | |
77 | /usr/spool/at/lasttimedone contains | |
78 | .I hhhh | |
79 | for last hour of activity. | |
80 | .br | |
81 | /usr/spool/at/past directory of activities now in progress | |
82 | .br | |
83 | /usr/lib/atrun program that executes activities that | |
84 | are due | |
85 | .br | |
86 | pwd(1) | |
87 | .SH "SEE ALSO" | |
88 | calendar(1), | |
89 | cron(1m) | |
90 | .SH DIAGNOSTICS | |
91 | Complains about various syntax errors and times out of range. | |
92 | .SH BUGS | |
93 | Due to the granularity of the execution of | |
94 | .I /usr/lib/atrun, | |
95 | there may be bugs in scheduling things almost | |
96 | exactly 24 hours into the future. |