sha1sum(1)


NAME

   sha1sum - compute and check SHA1 message digest

SYNOPSIS

   sha1sum [OPTION]... [FILE]...

DESCRIPTION

   Print or check SHA1 (160-bit) checksums.

   With no FILE, or when FILE is -, read standard input.

   -b, --binary
          read in binary mode

   -c, --check
          read SHA1 sums from the FILEs and check them

   --tag  create a BSD-style checksum

   -t, --text
          read in text mode (default)

   The following five options are useful only when verifying checksums:
   --ignore-missing
          don't fail or report status for missing files

   --quiet
          don't print OK for each successfully verified file

   --status
          don't output anything, status code shows success

   --strict
          exit non-zero for improperly formatted checksum lines

   -w, --warn
          warn about improperly formatted checksum lines

   --help display this help and exit

   --version
          output version information and exit

   The  sums  are computed as described in FIPS-180-1.  When checking, the
   input should be a former output of this program.  The default  mode  is
   to  print  a  line with checksum, a space, a character indicating input
   mode ('*' for binary, ' ' for text or where binary  is  insignificant),
   and name for each FILE.

AUTHOR

   Written by Ulrich Drepper, Scott Miller, and David Madore.

REPORTING BUGS

   GNU coreutils online help: <http://www.gnu.org/software/coreutils/>
   Report           sha1sum          translation          bugs          to
   <http://translationproject.org/team/>

COPYRIGHT

   Copyright  2016 Free Software Foundation, Inc.   License  GPLv3+:  GNU
   GPL version 3 or later <http://gnu.org/licenses/gpl.html>.
   This  is  free  software:  you  are free to change and redistribute it.
   There is NO WARRANTY, to the extent permitted by law.

SEE ALSO

   Full documentation at: <http://www.gnu.org/software/coreutils/sha1sum>
   or available locally via: info '(coreutils) sha1sum invocation'





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.