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Cron

cron is a time-based job scheduler. A scheduled job is known as a cron job. Although typically used to automate system maintenance and administration it can be used to automate any task. cron is most suitable for scheduling repetitive tasks, as scheduling a one-time task can be accomplished via at.

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History, Overview & Cron expression

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Explore the main themes, entities and connections around Cron. Start with the topic map, then use the sections below for research and deeper semantic analysis.

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Key facts & relationships

High-confidence facts extracted from structured source data. Use them as anchors for further research.

Developer
AT&T Bell Laboratories
Operating system
Unix and Unix-like, Plan 9, Inferno
Release
May 1975; 51 years ago (1975-05)
Type
Job scheduler
Written in
C

Topics to explore

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Overview

History

Cron expression

Advanced semantic analysis

Deeper signals for content research, entity SEO and topical coverage. The plain-language headings explain what each technical view is useful for.

Map overview Semantic statistics

Number of nodes, edges, triples, density and central hubs. Use it to gauge the size and connectivity of the map.

Cron

Nodes58
Edges57
Triples80
Avg. degree1.97
Density0.034483
Components1

How this topic connects Entity context

Quick relationship hints grouped by predicate. Useful for spotting recurring semantic connections around the current entity.

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Cron

Top relations

related to Modern versions · 15
Cron → Anacron, BSDs, GNU Project, In, ISC Cron, January, Linux, PAM, Paul Vixie, Red Hat, SELinux, The, Version, Vixie, With
related to Multi-user capability · 13
Cron → ACM, An, August, Communications, Franta, In, Kurt Maly, MIPS, The, Though, Unix, Unix System, Unix-like
related to Early versions · 6
Cron → Its, Read/usr/lib/crontabDetermine, Sleep, The, Unix, Version
related to External links · 6
Cron → ISC Cron, Shell, The Open GroupGNU, The Single UNIX Specification, Utilities Reference, Version
related to Standardization efforts · 5
Cron → In, OCPS, Open Cron Pattern Specification, The, Vixie
related to Nonstandard predefined scheduling definitions · 4
Cron → Debian, Since, Some, This
related to Time zone handling · 4
Cron → DST, Most, This, Thus
related to Non-standard characters · 3
Cron → Note, Quartz Java, The
related to overview · 3
Cron → Each, The, Users
see also · 3
Cron → LaunchdList, POSIX, Task Scheduler

Important terminology Word statistics

Frequent words and multi-word phrases across the lead, headings, infobox and body. Useful for terminology coverage.

Use these terms to understand the vocabulary surrounding the topic, not as a checklist for keyword stuffing.

Important terminology

time crontab daemon system job user run version file must users used task unix also scheduling files command event list

Entity relationships Subject–Predicate–Object triples

Extracted RDF-like relationships with confidence and source. The table includes structured facts and lower-confidence contextual relations.
SubjectPredicateObjectConfidenceSrc
CronDeveloperAT&T Bell Laboratories1.00infobox
CronOperating systemUnix and Unix-like, Plan 9, Inferno1.00infobox
CronReleaseMay 1975; 51 years ago (1975-05)1.00infobox
CronTypeJob scheduler1.00infobox
CronWritten inC1.00infobox
Cronis atime-based job scheduler0.90text
Cronis amere pattern-matcher0.90text
first-weekdayinstance ofas well as supporting additional expression features0.80text
last-day-of-month.Nonstandard predefined scheduling definitionsSome cron implementations support the following non-standard macrosinstance ofas well as supporting additional expression features0.80text
PAMinstance ofadding features0.80text
SELinux supportinstance ofadding features0.80text
predefined schedulesinstance ofwith future versions planned to incrementally add features0.80text

Related concept clusters Concept neighborhoods

Clusters of nearby vocabulary surrounding the topic. Scan them for adjacent concepts and language you may have missed.

These clusters group vocabulary that occurs around closely connected concepts in the source material.

    Connections between topic areas Semantic bridges

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