Mail::SpamAssassin::Util − utility functions
A general class for utility functions. Please use this for functions that stand alone, without requiring a $self object, Portability functions especially.
NOTE: The functions in this module are to be considered private. Their API may change at any point, and it’s expected that they’ll only be used by other Mail::SpamAssassin modules. ( TODO: we should probably revisit this if it’s useful for plugin development.)
Utility functions should not be changing global variables
such as $_, $1, $2, ... $/, etc.
unless explicitly documented. If these variables are in use
by these functions, they should be localized.
$module = first_available_module (@module_list)
Return the name of the first module that can be successfully loaded with "require" from the list. Returns "undef" if none are available.
This is used instead of "AnyDBM_File" as follows:
my $module = Mail::SpamAssassin::Util::first_available_module
(qw(DB_File GDBM_File NDBM_File SDBM_File));
tie %hash, $module, $path, [... args];
Note that "SDBM_File" is guaranteed to be present, since it comes with Perl.
my ($filepath, $filehandle) = secure_tmpfile();
Generates a filename for a temporary file, opens it exclusively and securely, and returns a filehandle to the open file (opened O_RDWR).
If it cannot open a file after 20 tries, it returns "undef".
my ($dirpath) = secure_tmpdir();
Generates a directory for temporary files. Creates it securely and returns the path to the directory.
If it cannot create a directory after 20 tries, it returns "undef".
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 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.
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.
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.