Job Scheduling - Part 1

Duration: 23 min

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Inside: a video lesson and guided study material.

Module outline

  1. About Course: UPPSC Course Overview
  2. Interview Preparation & Guidance: Interview Preparation
  3. Paper 1 | General Hindi: भाषा, लिपि, ध्वनि, वर्ण, अक्षर, स्वर, व्यंजन, मात्रा और संयुक्ताक्षर, वर्तनी, वर्ण-विन्यास, अनुस्वार, अनुनासिक, चंद्रबिंदु और ‘र’ के रूप, शब्द, पद और शब्द-भेद, हिन्दी की रूप रचना, संज्ञा और सर्वनाम, विशेषण और क्रिया, लिंग, वचन, पुरुष और कारक, काल, वाच्य, वाक्य और वाक्य-भेद, वर्णमाला, समास, संधि, Multi-Topic Content (Cross-Concept Material), हिन्दी की ध्वनि और स्वनिम व्यवस्था, प्राचीन और मध्यकालीन भारतीय आर्यभाषाएँ, काव्य के लक्षण, हेतु और प्रयोजन, हिन्दी शब्द रचना, हिन्दी साहित्येतिहास दर्शन, भक्तिकालीन काव्यधाराएँ, भारतीय काव्यशास्त्र की परंपरा, भारतीय नवजागरण और स्वाधीनता आंदोलन, अन्य गद्य विधाएँ एवं प्रवासी साहित्य, निर्धारित उपन्यासों का तुलनात्मक अध्ययन, गोदान, हिन्दी कहानी का विकास, स्वातंत्र्योत्तर और नयी कहानी, हिन्दी निबंध का विकास, शुक्लोत्तर निबंध, द्विवेदी और शुक्ल युग के निबंध, हिन्दी की संवैधानिक स्थिति, आधुनिक भारतीय आर्यभाषाएँ और हिन्दी का उद्भव, हिन्दी भाषा प्रयोग के विविध रूप, रीतिकाल, जीवनी, द्विवेदी युग और छायावाद, रीति, वक्रोक्ति और औचित्य सिद्धान्त, शब्दशक्ति और ध्वनि सिद्धान्त, रस सिद्धान्त और साधारणीकरण, उत्तर आधुनिकतावाद, लोहिया दर्शन, हिन्दी उपन्यास का विकास, हिन्दी नवजागरण, अंबेडकर दर्शन, आदिकाल, प्रयोगवाद और नयी कविता, छायावादी काव्य: प्रसाद और निराला, प्रगतिवाद से समकालीन कविता, निर्गुण भक्ति काव्य, द्विवेदीयुगीन काव्य, रीतिकालीन काव्य, आरंभिक हिन्दी उपन्यास, स्वातंत्र्योत्तर उपन्यास, आत्मकथा, स्वाधीनता-पूर्व प्रेमचंदोत्तर उपन्यास, निर्धारित कहानियों का तुलनात्मक अध्ययन, साठोत्तरी नाटक, प्रसाद और प्रसादोत्तर युग के नाटक, भारतेन्दु युगीन नाटक, स्वातंत्र्योत्तर नाटक, भारतेन्दु युगीन निबंध, संस्मरण और रेखाचित्र, व्यंग्य, एक साहित्यिक की डायरी, संस्कृति के चार अध्याय, सगुण भक्ति काव्य, हिन्दी नाटक, एकांकी और रंगमंच, आधुनिक गद्य और हिन्दी नवजागरण, अलंकार सिद्धान्त, हिन्दी आलोचना का विकास, भक्ति आंदोलन, कल्पना, बिम्ब, प्रतीक, मिथक और फंतासी, नयी कविता का विस्तार और साठोत्तरी कविता, उत्तर-छायावादी और प्रगतिवादी काव्य, काव्यगुण और काव्यदोष, प्लेटो, अरस्तू और पाश्चात्य परंपरा, मार्क्सवाद, स्वच्छन्दतावादी काव्यशास्त्र, आधुनिक पाश्चात्य आलोचना, भाषा और भाषा परिवार, देवनागरी लिपि
  4. Paper 2 | General Studies: State Wise GK, Polity, Geography, History, GK- Current Affairs
  5. Paper 1 | Programming Language: Language Design, C Fundamentals, Control Flow, Functions, Arrays & Pointers, Storage Classes, Structures & Enums, DMA, Macros, Scoping & File Handling, OOPS with C++
  6. Paper 1 | Database Management Systems: Basics of DBMS, ER Diagram, Relational Model & Functional Dependencies, Keys & Integrity Constraints, Normalization (1NF - BCNF), Decomposition Properties & 4NF, File Organization & Indexing, Relational Algebra, SQL, Relational Calculus, Transaction Management, Concurrency Control, ORDBMS, NoSQL
  7. Paper 1 | Cyber Security: कंप्यूटर की मूल बातें और हार्डवेयर / Computer Fundamentals and Hardware, प्रत्यक्ष बोध / Literal Comprehension, कंप्यूटर सॉफ्टवेयर / Computer Software, निष्कर्षात्मक बोध / Inferential Comprehension, आलोचनात्मक बोध / Critical Comprehension, इंटरनेट और वर्ल्ड वाइड वेब / Internet and World Wide Web, ई-मेल और ऑनलाइन संचार / Email and Online Communication, साइबर सुरक्षा / Cyber Security, अपशिष्ट प्रबंधन / Waste Management, डिजिटल नैतिकता, बौद्धिक संपदा और समाज / Digital Ethics, IPR and Society, डिजिटल एवं नव माध्यम / Digital and New Media, शोध नैतिकता / Research Ethics, उभरती प्रौद्योगिकियाँ / Emerging Technologies, शिक्षा और शासन में ICT / ICT in Education and Governance, Society, Law & Ethics, Cyber Threats and Malware Attacks, Role of Internet and Web Services, Security in Mobile and Wireless Computing, Electronic Data Interchange and E-Commerce, Physical Security and Cryptography Basics, Intrusion Detection Systems (IDS), Cyber Safety and Security, Ethical Hacking, भौगोलिक संकेतों का संरक्षण / Protection of Geographical Indications
  8. Paper 1 | Computer Organization and Architecture: Basics of COA, Programming the Basic Computer, Cache Memory Organization, Input Output Organisation, Instr Formats & Modes, Register Transfer and Microoperations, Control Unit Design
  9. Paper 1 | Computer Networks: Introduction to CN, Data Communication, DLL: Access Control, DLL: Flow Control, DLL: Error Control, DLL: Framing, Data Link Layer - Ethernet, Net Layer: IPv4 & Proto, Net Layer: IP Addressing, Net Layer:Routing Protocol, Transport Layer Services, TL: Congestion & UDP, Application Layer, Hardware basics, Network Security
  10. Paper 1 | Design and Analysis of Algorithms: Algorithm Analysis, Time Complexity Analysis, Sorting Algorithms, Greedy Algorithms, Dynamic Programming, Minimum Spanning Trees, Shortest Path Algos, Advanced Algorithms
  11. Paper 1 | Data Structures: Introduction to DS, Array, Linked List, Stack, Queue, Tree, Graphs, Hashing
  12. Paper 1 | Discrete Structures and Theory of Logic: क्रमचय, संचय एवं प्रायिकता / Permutation, Combination and Probability, Set Theory, Relations, Functions, Propositional and Predicate Logic, Graph Theory, Group Theory
  13. Paper 1 | Software Project Management: Software Project Management
  14. Paper 2 | Operating Systems: Introduction to OS, Process Management, CPU Scheduling, Process Synchronization, Threads & Process Creation, Deadlock, Memory Management, Virtual Memory, Disc Scheduling, File Management, Unix OS, Linux OS, Security
  15. Paper 2 | Compiler Design: Intro to Compilers, Lexical Analysis, Grammar & CFG, Syntax Analysis: Top-Down, Syntax Analysis: Bottom-Up, Semantic Analysis & SDT, Intermediate Code Gen, Code Optimization, Run Time Environment, Introduction to TOC, Deterministic FA (DFA), Non-Deterministic FA, Regular Expressions, Pushdown Automata & CFG, Complexity Theory
  16. Paper 2 | Artificial Intelligence & High Performance Computing: Approaches to AI, Search Algorithms, Game Playing, Knowledge Representation, Planning, Multi Agent Systems, Natural Language Processing, क्लाउड और वितरित कंप्यूटिंग / Cloud and Distributed Computing, Emerging Tech Trends
  17. Paper 2 | Image Processing: Digital Image Fundamentals, Image Enhancement, Image Restoration, Color Image Processing, Image Compression
  18. Paper 2 | Software Engineering: Fundamentals of Software Engineering, Software Requirements and Quality Assurance, Software Design, Estimation and Metrics, Software Testing, Software Maintenance and Configuration Management
  19. Paper 2 | Computer Graphics: Basics of Computer Graphics, 2-D Geometrical Transforms and Viewing, 3-D Object Representation, Geometric Transformations and Viewing
  20. Paper 2 | Web Technologies: Website, Browser & Services, Internet Fundamentals, Web Design & Development, Protocols & Services, Web Publishing & Hosting, Server Side & Security, Emerging Technologies, HTML Basics, JavaScript-Basics, Java
  21. Paper 2 | Soft Computing: Fuzzy Sets, Artificial Neural Networks, Genetic Algorithms
  22. Paper 2 | Distributed System: Distributed Systems
  23. UPPSC Live Class Recordings: UPPSC Polytechnic Lecturer 2025 (CS)
  24. Previous Year Papers:
  25. Mock Test:
AI summary & chapters

AI Summary

An AI-generated summary of this video lecture.

This lecture introduces job scheduling in Linux, focusing on the cron system. It begins by defining job scheduling as automatically running commands or tasks at specified times, highlighting its use for repetitive tasks like backups and maintenance. The lecture distinguishes between one-time jobs and recurring jobs, using an 11 PM backup as a common example. The core of the lesson covers cron and crond, explaining that cron is the time-based scheduler while crond is the background daemon that executes jobs. A detailed breakdown of the cron syntax (minute, hour, day of month, month, day of week) is provided using the example '0 2 * * * /home/user/backup.sh', which runs a backup script daily at 2:00 AM. The lecture also covers the crontab command and its essential flags (-e, -l, -r, -u) for managing scheduled jobs. Finally, it concludes with a table of practical examples, such as running tasks every minute, at specific times like 10:30 AM, on specific days of the week or month, and at intervals like every 5 minutes.

Chapters

  1. 0:00 – 2:00 00:00-02:00

    The lecture opens with a title slide for 'Linux OS' and the topic 'Job Scheduling'. The instructor introduces job scheduling as a method for automatically running commands or tasks at specified times. A slide titled 'Job Scheduling Commands in Linux' lists reasons for its use, including backing up files, running reports, and deleting temporary files. The instructor uses red underlines to emphasize key terms like 'automatically running a command or task' and 'specified time'. A table comparing one-time jobs (runs once) and recurring jobs (runs repeatedly at fixed intervals) is introduced, with an 11 PM backup example for both.

  2. 2:00 – 5:00 02:00-05:00

    The instructor continues to emphasize the importance of job scheduling for repetitive tasks, using red circles around phrases like 'repetitive tasks', 'specific time', and 'manual intervention'. The lecture transitions to a slide titled 'LINUX JOB SCHEDULING COMMANDS', which presents several color-coded command tables. This section serves as a bridge between the conceptual introduction and the specific technical commands used in Linux for scheduling, setting up the detailed explanation of cron and crond that follows.

  3. 5:00 – 10:00 05:00-10:00

    The lecture focuses on 'cron and crond', defining cron as a time-based job scheduler in Linux for repetitive or recurring tasks. The instructor highlights key phrases like 'commands or scripts' and 'repetitive/recurring tasks'. A specific cron example, '0 2 * * * /home/user/backup.sh', is broken down field by field. The instructor annotates the line, labeling each field as minute, hour, day of month, month, and day of week. The example is explained to mean the backup script runs every day at 2:00 AM, connecting abstract syntax to a concrete real-world outcome.

  4. 10:00 – 15:00 10:00-15:00

    The lecture shifts to 'crond', defined as the background daemon or service that runs and manages scheduled cron jobs. It continuously checks schedules and executes commands when their time arrives. A two-column table titled 'cron vs crond' compares the two, noting that cron is the scheduling mechanism while crond is the execution daemon. An example flowchart illustrates the process: crontab defines the job, crond manages it, and the command or script executes. Red teaching marks progressively underline key definitions to reinforce the distinction between the scheduler and the daemon.

  5. 15:00 – 20:00 15:00-20:00

    The lecture covers the 'crontab' command, used to create, view, edit, and remove scheduled jobs. A table of 'Important crontab Commands' lists the flags -e (edit), -l (list), -r (remove), and -u username, each highlighted in red boxes. A 'Basic Workflow' panel outlines four steps, ending with cron/crond executing the command automatically. The instructor emphasizes that crontab is the user-facing tool for interacting with the cron system, while crond operates in the background to ensure jobs run on time.

  6. 20:00 – 23:03 20:00-23:03

    The lecture concludes with a 'crontab - Example & Explanation' slide. Step 1 shows opening the crontab editor with 'crontab -e', and step 2 displays the line '0 2 * * * /home/user/backup.sh'. A green panel explains this means the backup script executes every day at 2:00 AM. A 'CRON FIELDS EXPLAINED' table and a quick tip stating '* means every' are provided. An 'EXAMPLES' table lists five scenarios: running every minute (* * * * *), at 10:30 AM daily (30 10 * * *), every Monday at 9:00 AM (0 9 * * 1), on the 15th at 8:00 PM (0 20 15 * *), and every 5 minutes (*/5 * * *).

The lecture provides a structured introduction to job scheduling in Linux, moving from conceptual definitions to practical command usage. It begins by establishing the purpose of job scheduling: automating repetitive tasks like backups and maintenance at specified times. The distinction between one-time and recurring jobs is clarified early on, with recurring jobs being the primary focus due to their reliance on cron. The core technical content centers on the relationship between cron (the scheduler) and crond (the daemon), using a comparison table to highlight their distinct roles. The cron syntax is taught through a detailed, field-by-field breakdown of the example '0 2 * * * /home/user/backup.sh', making the abstract five-field format concrete. The crontab command is presented as the user interface for managing these jobs, with its key flags (-e, -l, -r) explained. The lecture culminates in a series of practical examples that demonstrate the flexibility of cron syntax for various scheduling needs, from minute-by-minute execution to specific dates and times. This progression ensures students understand both the 'why' and 'how' of job scheduling in Linux.

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