When it comes to managing the time-controlled execution of programs, you can use the entries in the /etc/ crontab file (crontab) for repetitive tasks scheduled at regular intervals, or you can use the at command for a one-time action.
While at uses a kind of order book that stores the commands to be executed at a scheduled time, cron works somewhat differently. The crontab contains the entries for the whole system, while the files in /var/spool/cron/crontabs/ contain user-specific entries. Each line in the crontab fully describes a single job. Care must be taken when specifying the jobs because of the entry format’s fairly arcane syntax. You can learn this syntax, but it is by no means a trivial task. If you have an LPIC-1 certificate, you will be familiar with the entry format.
Despite care and attention, you may find out that jobs fail to start or are executed at the wrong time. A graphical user interface (GUI) can help reduce errors, even for experienced users. However, several earlier attempts at a suitable GUI for time-controlled calls (e.g., KCron, Kcrontab, CroMagnon, Gnome Schedule [1], Gnome Task Scheduler [2], and VCron) have fallen short with development coming to a standstill.
Zeit [3], a graphic front end for at and crontab, promises to remedy this situation and make managing time-triggered events easier. In development since 2015, Zeit is now considered stable for use and offers both English and Russian versions.
Installation
Denne historien er fra #261/August 2022-utgaven av Linux Magazine.
Start din 7-dagers gratis prøveperiode på Magzter GOLD for å få tilgang til tusenvis av utvalgte premiumhistorier og 9000+ magasiner og aviser.
Allerede abonnent ? Logg på
Denne historien er fra #261/August 2022-utgaven av Linux Magazine.
Start din 7-dagers gratis prøveperiode på Magzter GOLD for å få tilgang til tusenvis av utvalgte premiumhistorier og 9000+ magasiner og aviser.
Allerede abonnent? Logg på
Tracking your finances with plain text accounting Plain Numbers
If you're tired of tinkering with spreadsheets, using hledger and plain text accounting offers a simpler method for managing your finances without vendor lock-in
Dependency resolution with apt-get and apt Evolutionary Tale
Over the past 30 years, the apt family has played an important role in dependency resolution for Debian distros.
Cryptomining with Litecoin Traveling Lite
Although not as popular as headliners like Bitcoin and Ethereum, Litecoin is one of the oldest crytocurrencies, and it offers some useful features, such as dual-mining with Dogecoin.
Software Update SnoopGod
SnoopGod delivers an Ubuntu-based pentesting distribution with an emphasis on security education.
Kernel Trouble
This deep look at how intruders attack an out-of-date kernel should be enough to convince you of the need to stay vigilant.
Using Wake-on-LAN for a NAS backup Power Saver
Put your backup server to sleep when you don't need it and then wake it on demand using the Wake-on-LAN feature built into network adapters.
Time Travel
Mike Schilli uses a Go program to check whether a strategy for trading stocks is making gains or losses on the basis of historical price data.
URL filtering with Pi-hole Into the Funnel
Supporting browser plug-ins, network-based DNS blockers like Pi-hole help protect you against online tracking and unwanted content.
Artificial intelligence on the Raspberry Pi Learning Experience
You don't need a powerful computer system to use Al. We show what it takes to benefit from Al on the Raspberry Pi and what tasks the small computer can handle.
MakerSpace Manage your greenhouse with a Raspberry Pi Pico W Sheltered Growth
You can safely assign some greenhouse tasks to a Raspberry Pi Pico W, such as controlling ventilation, automating a heater, and opening and closing windows.
