Cron
Apparently you can schedule a file to run with cron command natively in bash :0
0 wget -O - -q -t 1 http://CRON_URL
If you computer is off when it was supposed to be run, doesn't run it
anacrontab apparently can run these jobs after the fact
Other cron syntax
Operator | Purpose | Example |
asterisk ( * ) | Specifies all possible values for a field | An asterisk in the hour time field is equivalent to “every hour.” |
question mark (?) | A question mark ( ? ) is allowed in the day-of-month and day-of-week fields. It is used to specify “no specific value,” which is useful when you need to specify something in one of these two fields, but not in the other. | If you want a trigger to fire on a particular day of the month (for example, the 10th), but you don't care what day of the week that is, enter 10 in the day-of-month field, and ? in the day-of-week field. |
dash ( - ) | Specifies a range of values | 2-5, which is equivalent to 2,3,4,5 |
comma ( , ) | Specifies a list of values | 1,3,4,7,8 |
slash ( / ) | Used to skip a given number of values | /3 in the hour time field is equivalent to 0,3,6,9,12,15,18,21. The asterisk ( ) specifies “every hour,” but the /3 means only the first, fourth, seventh.You can use a number in front of the slash to set the initial value. For example, 2/3 means 2,5,8,11, and so on. |
L (“last”) | The L character is allowed for the day-of-month and day-of-week fields.Specifies either the last day of the month, or the last xxx day of the month. | The value L in the day-of-month field means “the last day of the month,” which is day 31 for January, or day 28 for February in non-leap years. If you use L in the day-of-week field by itself, it simply means 7 or SAT. But if you use it in the day-of-week field after another value, it means “the last xxx day of the month.” For example, 6L means “the last Friday of the month.”HINT:When you use the L option, be careful not to specify lists or ranges of values. Doing so causes confusing results. |
W (“weekday”) | The W character is allowed for the day-of-month field.Specifies the weekday (Monday-Friday) nearest the given day. | If you specify 15W as the value for the day-of-month field, the meaning is “the nearest weekday to the 15th of the month.” So if the 15th is a Saturday, the trigger fires on Friday the 14th. If the 15th is a Sunday, the trigger fires on Monday the 16th. If the 15th is a Tuesday, it fires on Tuesday the 15th. However, if you specify 1W as the value for day-of-month, and the 1st is a Saturday, the trigger fires on Monday the 3rd, because it does not “jump” over the boundary of a month’s days. The W character can only be specified when the day-of-month is a single day, not a range or list of days.HINT:You can combine the L and W characters for the day-of-month expression to yield LW, which translates to “last weekday of the month.” |
pound sign ( # ) | The pound sign ( # ) character is allowed for the day-of-week field. This character is used to specify “the nth” xxx day of the month. | The value of 6#3 in the day-of-week field means the third Friday of the month (day 6 = Friday and #3 = the 3rd one in the month).Other Examples: 2#1 specifies the first Monday of the month and 4#5 specifies the fifth Wednesday of the month. However, if you specify #5 and there are fewer than 5 of the given day-of-week in the month, no firing occurs that month. |
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