79 lines
2.1 KiB
Markdown
79 lines
2.1 KiB
Markdown
---
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title: Cron
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category: CLI
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updated: 2024-03-17
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weight: -3
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---
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## Format
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{: .-two-column}
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### Format
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```
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Min Hour Day Mon Weekday
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```
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{: .-setup}
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```
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* * * * * command to be executed
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```
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```
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┬ ┬ ┬ ┬ ┬
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│ │ │ │ └─ Weekday (0=Sun .. 6=Sat)
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│ │ │ └────── Month (1..12)
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│ │ └─────────── Day (1..31)
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│ └──────────────── Hour (0..23)
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└───────────────────── Minute (0..59)
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```
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{: .-setup.-box-chars}
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### Operators
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| Operator | Description |
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| --- | --- |
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| `*` | all values |
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| `,` | separate individual values |
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| `-` | a range of values |
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| `/` | divide a value into steps |
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### Special strings
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| String | Description |
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| --- | --- |
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| `@reboot` | every rebot |
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| `@hourly` | once every hour - same as `0 * * * *` |
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| `@daily` | once every day - same as `0 0 * * *` |
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| `@midnight` | once every midnight - same as `@daily` |
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| `@weekly` | once every week - same as `0 0 * * 0` |
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| `@monthly` | once every month - same as `0 0 1 * *` |
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| `@yearly` | once every year - same as `0 0 1 1 *` |
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### Examples
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| Example | Description |
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| --- | --- |
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| `0 * * * *` | every hour |
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| `*/15 * * * *` | every 15 mins |
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| `0 */2 * * *` | every 2 hours |
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| `0 18 * * 0-6` | every week Mon-Sat at 6pm |
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| `10 2 * * 6,7` | every Sat and Sun on 2:10am |
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| `0 0 * * 0` | every Sunday midnight |
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### Crontab
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```bash
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# Adding tasks easily
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echo "@reboot echo hi" | crontab
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# Open in editor - optional for another user
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crontab -e [-u user]
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# List tasks - optional for another user
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crontab -l [-u user]
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# Delete crontab file - optional for another user
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crontab -r [-u user]
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```
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