Free Knowledge Resources


Linux Manual Pages


Free Software * Books

Source Code

Free Media

Linux

crontab(1)


NAME

   crontab - maintain crontab files for individual users

SYNOPSIS

   crontab [-u user] file
   crontab [-u user] [-l | -r | -e | -s] [-i]

   (blank)
          default operation is replace

   -u, --user
          edit some other user's crontab

   -l, --list
          list user's crontab

   -r, --remove
          delete user's crontab

   -e, --edit
          edit user's crontab

   -s, --show
          show all user who have a crontab

   -i, --ask
          prompt before deleting user's crontab

DESCRIPTION

   Crontab  is  the  program  used to let users install, deinstall or list
   recurrent jobs in the legacy cron format.
   Each user can have their own crontab, and though  these  are  files  in
   /var/spool/cron/crontabs, they are not intended to be edited directly.
   These  jobs are then automatically translated in systemd Timers & Units
   by systemd-crontab-generator.

FILES

   /var/spool/cron/crontabs
          Directory for users crontabs.

   /etc/cron.allow
          list of users that can use crontab

   /etc/cron.deny
          list of users that aren't allowed to use crontab
          (by default, only root can use crontab)

LIMITATIONS

   SELinux is not supported.

AUTHOR

   Konstantin Stepanov <me@kstep.me>
   Alexandre Detiste <alexandre@detiste.be>  for  this  manpage  &  setgid
   helper



Opportunity


Personal Opportunity - Free software gives you access to billions of dollars of software at no cost. Use this software for your business, personal use or to develop a profitable skill. Access to source code provides access to a level of capabilities/information that companies protect though copyrights. Open source is a core component of the Internet and it is available to you. Leverage the billions of dollars in resources and capabilities to build a career, establish a business or change the world. The potential is endless for those who understand the opportunity.

Business Opportunity - Goldman Sachs, IBM and countless large corporations are leveraging open source to reduce costs, develop products and increase their bottom lines. Learn what these companies know about open source and how open source can give you the advantage.



Free Software


Free Software provides computer programs and capabilities at no cost but more importantly, it provides the freedom to run, edit, contribute to, and share the software. The importance of free software is a matter of access, not price. Software at no cost is a benefit but ownership rights to the software and source code is far more significant.

Free Office Software - The Libre Office suite provides top desktop productivity tools for free. This includes, a word processor, spreadsheet, presentation engine, drawing and flowcharting, database and math applications. Libre Office is available for Linux or Windows.



Free Books


The Free Books Library is a collection of thousands of the most popular public domain books in an online readable format. The collection includes great classical literature and more recent works where the U.S. copyright has expired. These books are yours to read and use without restrictions.

Source Code - Want to change a program or know how it works? Open Source provides the source code for its programs so that anyone can use, modify or learn how to write those programs themselves. Visit the GNU source code repositories to download the source.



Education


Study at Harvard, Stanford or MIT - Open edX provides free online courses from Harvard, MIT, Columbia, UC Berkeley and other top Universities. Hundreds of courses for almost all major subjects and course levels. Open edx also offers some paid courses and selected certifications.

Linux Manual Pages - A man or manual page is a form of software documentation found on Linux/Unix operating systems. Topics covered include computer programs (including library and system calls), formal standards and conventions, and even abstract concepts.


birds banner