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Anacron
anacron is a computer program that performs periodic command scheduling, which is traditionally done by cron, but without assuming that the system is running continuously. Thus, it can be used to control the execution of daily, weekly, and monthly jobs (or anything with a period of ''n'' days) on systems that don't run 24 hours a day. anacron was originally conceived and implemented by Christian Schwarz in Perl, for the Unix operating system. It was later rewritten in C by Itai Tzur; maintainers have included Sean 'Shaleh' Perry and Pascal Hakim. Since 2009, Red Hat's cron implementation, cronie, has included anacron. Since then, anacron has been updated by Red Hat as a part of cronie. Advantages Unix systems commonly run "housekeeping chores" such as log rotation, unused files deletion, indexing local files for the search engine, sending disk usage reports, etc. A program called cron may be used to schedule these tasks. With cron, tasks are commonly scheduled to be exec ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fcron
fcron is a computer program with a GNU General Public License (GNU GPL) license that performs periodic command scheduling. It has been developed on Linux and should work on POSIX systems. As with Anacron, it does not assume that the system is running continuously, and can run in systems that do not run all the time or regularly. It aims to replace Vixie-cron and Anacron with a single integrated program, providing many features missing from the original Cron daemon. Some of the supported options permit: * run jobs one by one * set the max system load average value under which the job should be run * set a nice value for a job * run jobs at fcron's startup if they should have been run during system down time * mail user to tell them a job has not run and why * run fcron by scripts * run several instances of fcron simultaneously * have fcron exit after it has run the pending jobs See also * Cron * List of Unix commands This is a list of the shell commands of the most recent ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cron
The cron command-line utility is a job scheduler on Unix-like operating systems. Users who set up and maintain software environments use cron to schedule jobs (commands or shell scripts), also known as cron jobs, to run periodically at fixed times, dates, or intervals. It typically automates system maintenance or administration—though its general-purpose nature makes it useful for things like downloading files from the Internet and downloading email at regular intervals. Cron is most suitable for scheduling repetitive tasks. Scheduling one-time tasks can be accomplished using the associated ''at'' utility. Cron's name originates from Chronos, the Greek word for time. Overview The actions of cron are driven by a crontab (cron table) file, a configuration file that specifies shell commands to run periodically on a given schedule. The crontab files are stored where the lists of jobs and other instructions to the cron daemon are kept. Users can have their own individual cr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Vixiecron
The cron command-line utility is a job scheduler on Unix-like operating systems. Users who set up and maintain software environments use cron to schedule jobs (commands or shell scripts), also known as cron jobs, to run periodically at fixed times, dates, or intervals. It typically automates system maintenance or administration—though its general-purpose nature makes it useful for things like downloading files from the Internet and downloading email at regular intervals. Cron is most suitable for scheduling repetitive tasks. Scheduling one-time tasks can be accomplished using the associated ''at'' utility. Cron's name originates from Chronos, the Greek word for time. Overview The actions of cron are driven by a crontab (cron table) file, a configuration file that specifies shell commands to run periodically on a given schedule. The crontab files are stored where the lists of jobs and other instructions to the cron daemon are kept. Users can have their own individual cront ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
C (programming Language)
C (''pronounced'' '' – like the letter c'') is a general-purpose programming language. It was created in the 1970s by Dennis Ritchie and remains very widely used and influential. By design, C's features cleanly reflect the capabilities of the targeted Central processing unit, CPUs. It has found lasting use in operating systems code (especially in Kernel (operating system), kernels), device drivers, and protocol stacks, but its use in application software has been decreasing. C is commonly used on computer architectures that range from the largest supercomputers to the smallest microcontrollers and embedded systems. A successor to the programming language B (programming language), B, C was originally developed at Bell Labs by Ritchie between 1972 and 1973 to construct utilities running on Unix. It was applied to re-implementing the kernel of the Unix operating system. During the 1980s, C gradually gained popularity. It has become one of the most widely used programming langu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
At (command)
at is a shell command for scheduling commands to be executed at a future time; once. The command was developed for Unix and is available on Unix and Unix-like systems, Windows, and ReactOS. Variants Unix-like On Unix-like operating systems, at reads a series of commands from standard input and collects them into one "at-job" which is carried out at a later date. The job inherits the current environment, so that it is executed in the same working directory and with the same environment variables set as when it was scheduled. It differs from cron, which is used for recurring executions (e.g. once an hour, every Tuesday, January 1 every year). As with cron, many Unix systems allow the administrator to restrict access to the at command. at can be made to mail a user when done carrying out a scheduled job, can use more than one job queue, and can read a list of jobs to carry out from a file instead of standard input. The Linux at command was mostly written by Thomas Koenig. Th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
List Of Unix Commands
This is a list of the shell commands of the most recent version of the Portable Operating System Interface (POSIX) IEEE Std 1003.1-2024 which is part of the Single UNIX Specification (SUS). These commands are implemented in many shells on modern Unix, Unix-like and other operating systems. This list does not cover commands for all versions of Unix and Unix-like shells nor other versions of POSIX. See also * GNOME Core Applications * GNU Core Utilities * List of GNU packages * List of KDE applications * List of Unix daemons * Unix philosophy The Unix philosophy, originated by Ken Thompson, is a set of cultural norms and philosophical approaches to Minimalism (computing), minimalist, Modularity (programming), modular software development. It is based on the experience of leading devel ... * References External links IEEE Std 1003.1,2004 specificationsIEEE Std 1003.1,2008 specificationsIEEE Std 1003.1,2024 specifications– configurable list of equivalent pro ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Log Rotation
In information technology, log rotation is an automated process used in system administration in which log files are compressed, moved (archived), renamed or deleted once they are too old or too big (there can be other metrics that can apply here). New incoming log data is directed into a new fresh file (at the same location). The main purpose of log rotation is to restrict the volume of the log data to avoid overflowing the record store, while keeping the log files small enough so viewers can still open them. Servers which run large applications, such as LAMP stacks, often log every request: in the face of bulky logs, log rotation provides a way to limit the total size of the logs retained while still allowing analysis of recent events. Even though some arguments in favor of log rotation imply that maintaining smaller files increases writing performance, the size of a file doesn’t affect its writing performance. The reason is that in most modern filesystem implementation ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
System Administrator
An IT administrator, system administrator, sysadmin, or admin is a person who is responsible for the upkeep, configuration, and reliable operation of computer systems, especially multi-user computers, such as Server (computing), servers. The system administrator seeks to ensure that the uptime, Computer performance, performance, System resource, resources, and Computer security, security of the computers they manage meet the needs of the User (computing), users, without exceeding a set budget when doing so. To meet these needs, a system administrator may acquire, install, or upgrade computer components and software; provide routine automation; maintain security policies; troubleshoot; train or supervise staff; or offer technical support for projects. Related fields Many organizations staff offer jobs related to system administration. In a larger company, these may all be separate positions within a computer support or Information Services (IS) department. In a smaller group ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Linux
Linux ( ) is a family of open source Unix-like operating systems based on the Linux kernel, an kernel (operating system), operating system kernel first released on September 17, 1991, by Linus Torvalds. Linux is typically package manager, packaged as a Linux distribution (distro), which includes the kernel and supporting system software and library (computing), libraries—most of which are provided by third parties—to create a complete operating system, designed as a clone of Unix and released under the copyleft GPL license. List of Linux distributions, Thousands of Linux distributions exist, many based directly or indirectly on other distributions; popular Linux distributions include Debian, Fedora Linux, Linux Mint, Arch Linux, and Ubuntu, while commercial distributions include Red Hat Enterprise Linux, SUSE Linux Enterprise, and ChromeOS. Linux distributions are frequently used in server platforms. Many Linux distributions use the word "Linux" in their name, but the Free ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
