Free Knowledge Resources


Linux Manual Pages


Free Software * Books

Source Code

Free Media

Linux

dpkg-trigger(1)


NAME

   dpkg-trigger - a package trigger utility

SYNOPSIS

   dpkg-trigger [option...] trigger-name
   dpkg-trigger [option...] command

DESCRIPTION

   dpkg-trigger  is  a  tool to explicitly activate triggers and check for
   its support on the running dpkg.

   This can be used by  maintainer  scripts  in  complex  and  conditional
   situations  where  the  file  triggers,  or  the  declarative  activate
   triggers control file directive, are insufficiently rich. It  can  also
   be  used  for  testing  and by system administrators (but note that the
   triggers won't actually be run by dpkg-trigger).

   Unrecognized trigger name syntaxes are an error for dpkg-trigger.

COMMANDS

   --check-supported
          Check if the running dpkg supports triggers (usually called from
          a  postinst). Will exit 0 if a triggers-capable dpkg has run, or
          1 with an error message to stderr if not. Normally, however,  it
          is   better   just   to   activate   the  desired  trigger  with
          dpkg-trigger.

   -?, --help
          Show the usage message and exit.

   --version
          Show the version and exit.

OPTIONS

   --admindir=dir
          Change the location of the dpkg database. The  default  location
          is /var/lib/dpkg.

   --by-package=package
          Override  trigger  awaiter  (normally  set  by  dpkg through the
          DPKG_MAINTSCRIPT_PACKAGE environment variable of the  maintainer
          scripts,  naming  the  package  to which the script belongs, and
          this will be used by default).

   --no-await
          This option arranges that the calling package T  (if  any)  need
          not  await  the  processing  of  this  trigger;  the  interested
          package(s) I, will  not  be  added  to  T's  trigger  processing
          awaited  list  and T's status is unchanged.  T may be considered
          installed even though I may not yet have processed the trigger.

   --await
          This option does the inverse of --no-await (since dpkg 1.17.21).
          It is currently the default behavior.

   --no-act
          Just test, do not actually change anything.

EXIT STATUS

   0      The  requested action was successfully performed.  Or a check or
          assertion command returned true.

   1      A check or assertion command returned false.

   2      Fatal or unrecoverable error due to invalid command-line  usage,
          or  interactions  with  the  system,  such  as  accesses  to the
          database, memory allocations, etc.

ENVIRONMENT

   DPKG_ADMINDIR
          If set and the --admindir option has not been specified, it will
          be used as the dpkg data directory.

SEE ALSO

   dpkg(1), deb-triggers(5), /usr/share/doc/dpkg-dev/triggers.txt.gz.



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