NAME File::Package - test load a pm and import symbols without eval and $@ misbehavoirs SYNOPSIS ########## # Subroutine interface # use File::Package qw(is_package_loaded load_package); $yes = is_package_loaded($package, $program_module); $error = load_package($program_module); $error = load_package($program_module, @import); $error = load_package($program_module, [@package_list]); $error = load_package($program_module, @import, [@package_list]); ########## # Class Interface # use File::Package; $yes = is_package_loaded($package, $program_module); $error = File::Package->load_package($program_module); $error = File::Package->load_package($program_module, @import); $error = File::Package->load_package($program_module, [@package_list]); $error = File::Package->load_package($program_module, @import, [@package_list]); DESCRIPTION In a perfect Perl, everything would behave exactly the same running under "eval". Many times the reason to use an "eval" is the anticipation that the expression may die. When that happens, a perfect Perl would have deposited all the output fromm the "warn" and "die" in "$@". Maybe you have a perfect Perl. However, it is shocking that there are some Perls on some platforms out in the wild that are mutants and are not perfect. A "require" under eval works just fine just to see if a program will load or not. If working locally, you can simply devise a quick debug setup and track down the problem. However, when running tests remotely, on different remote platforms, running continuously unattended where uptime is important, or any number of situations it is very helpful to have meaningful error messages when a problem arise. Thus, the reason to run under "eval" is not only to avoid the "die" but also to pick up the error message returned by "eval" in "$@". In certain situations it is extremely critical to obtain reliable error messages when a failure occurs. Well, a "eval "require $program_module"" failure returns a reasonble looking "$@" except for one small thing. Not all the warnings make it to "$@" at least on one Perl, probably more. And there can be quite a few warnings when loading a broken program module. It would be nice if everyone could update to a Perl where the "eval" deposits all the warnings in "$@". But as the acient proverb says, "If wishes were horses, beggers would ride.". One workaround is to catch the warnings with "$SIG{__WARN__}" when running the "require" under a "eval". This collects all the warnings which is good. Now when a load fails, the program does not die, it gracefully collects all the warnings and logs them or ships back. Now try the "import" under "eval" and pick up the error messages. The "import" and "eval" is big time "failure to communicate" aka the movie "Cool Hand Luke". The "import" uses the caller stack to determine where to stuff the symbols and there is a lot of "Carp" "croak" gyrations such as making "import" look like "use", trapping "warnings" and "dies". The "eval" takes off on its own caller stack which to quote President Bush: "is not helpful". The "import" uses the "croak" instead of "die" directly or else any efforts to get meaningfull error messages would be dead on arrival. Perl is designed so that it is nearly impossible to avoid a die unless running under a "eval". A workaround is hooking in a "croak" that does not die and collecting the error messages. Subroutines is_package_loaded $package = is_package_loaded($program_module, $package) The "is_package_loaded" subroutine determines if the "$package" is present and the "$progarm_module" loaded. If "$package" is absent, 0 or '', "$package" is set to the "program_module". load_package $error = load_package($program_module, @import, [@package_list]); The "load_package" subroutine attempts to capture any load problems by loading the package with a "require " under an eval and capturing all the "warn" and $@ messages. If the "$program_module" load is successful, the checks that the packages in the @package list are present. If @package list is absent, the "$program_module" uses the "program_module" name as a list of one package. Although a program module and package have the same name syntax, they are entirely different. A program module is a file. A package is a hash of symbols, a symbol table. The Perl convention is that the names for each are the same which enhances the appearance that they are the same when in fact they are different. Thus, a program module may have a single package with a different name or many different packages. Finally the "$program_module" subroutine will import the symbols in the "@import" list. If "@import" is absent "$program_module" subroutine does not import any symbols; if "@import" is '', all symbols are imported. A "@import" of 0 usually results in an "$error". The "$program_module" traps all load errors and all import "Carp::Crock" errors and returns them in the "$error" string. One very useful application of the "load_package" subroutine is in test scripts. If a package does load, it is very helpful that the program does not die and reports the reason the package did not load. This information is readily available when loaded at a local site. However, it the load occurs at a remote site and the load crashes Perl, the remote tester usually will not have this information readily available. Other applications include using backup alternative software if a package does not load. For example if the package 'Compress::Zlib' did not load, an attempt may be made to use the gzip system command. BUGS The "load_package" cannot load program modules whose name contain the '-' characters. The 'eval' function used to trap the die errors believes it means subtraction. REQUIREMENTS Coming. DEMONSTRATION ######### # perl Package.d ### ~~~~~~ Demonstration overview ~~~~~ Perl code begins with the prompt => The selected results from executing the Perl Code follow on the next lines. For example, => 2 + 2 4 ~~~~~~ The demonstration follows ~~~~~ => use File::Package; => my $uut = 'File::Package'; => ################## => # Good Load => # => ### => my $error = $uut->load_package( 'File::Basename' ) '' => $error = $uut->load_package( '_File_::BadLoad' ) 'Cannot load _File_::BadLoad syntax error at E:/User/SoftwareDiamonds/installation/t/File/_File_/BadLoad.pm line 13, near "$FILE " Global symbol "$FILE" requires explicit package name at E:/User/SoftwareDiamonds/installation/t/File/_File_/BadLoad.pm line 13. Compilation failed in require at (eval 12) line 1. Scalar found where operator expected at E:/User/SoftwareDiamonds/installation/t/File/_File_/BadLoad.pm line 13, near "$FILE" (Missing semicolon on previous line?) ' => $uut->load_package( '_File_::BadPackage' ) '# _File_::BadPackage file but package(s) _File_::BadPackage absent. ' => $uut->load_package( '_File_::Multi' ) '# _File_::Multi file but package(s) _File_::Multi absent. ' => $error = $uut->load_package( '_File_::Hyphen-Test' ) 'Cannot load _File_::Hyphen-Test syntax error at (eval 15) line 1, near "require _File_::Hyphen-" Warning: Use of "require" without parens is ambiguous at (eval 15) line 1. ' => ################## => # No &File::Find::find import baseline => # => ### => !defined($main::{'find'}) '1' => ################## => # Load File::Find, Import &File::Find::find => # => ### => $error = $uut->load_package( 'File::Find', 'find', ['File::Find'] ) '' => ################## => # &File::Find::find imported => # => ### => defined($main::{'find'}) '1' => ################## => # &File::Find::finddepth not imported => # => ### => !defined($main::{'finddepth'}) '1' => ################## => # Import error => # => ### => $uut->load_package( 'File::Find', 'Jolly_Green_Giant') '"Jolly_Green_Giant" is not exported by the File::Find module Can't continue after import errors at D:/Perl/lib/Exporter/Heavy.pm line 127 Exporter::heavy_export('File::Find', 'main', 'Jolly_Green_Giant') called at D:/Perl/lib/Exporter.pm line 45 Exporter::import('File::Find', 'Jolly_Green_Giant') called at (eval 9) line 81 File::Package::load_package('File::Package', 'File::Find', 'Jolly_Green_Giant') called at E:\User\SoftwareDiamonds\installation\t\File\Package.d line 195 ' => ################## => # &File::Find::finddepth still no imported => # => ### => !defined($main::{'finddepth'}) '1' => ################## => # Import all File::Find functions => # => ### => $error = $uut->load_package( 'File::Find', '') '' => ################## => # &File::Find::finddepth imported => # => ### => defined($main::{'finddepth'}) '1' QUALITY ASSURANCE Running the test script "package.t" verifies the requirements for this module. The cover script for Test::STDmaker automatically generated the "package.t" test script, "package.d" demo script, and "t::File::Package" STD program module POD, from the "t::File::Package" program module contents. The "t::File::Package" program module is in the distribution file File-Package-$VERSION.tar.gz. NOTES AUTHOR The holder of the copyright and maintainer is COPYRIGHT NOTICE Copyrighted (c) 2002 Software Diamonds All Rights Reserved BINDING REQUIREMENTS NOTICE Binding requirements are indexed with the pharse 'shall[dd]' where dd is an unique number for each header section. This conforms to standard federal government practices, 490A (the 3.2.3.6 entry in the STD490A manpage). In accordance with the License, Software Diamonds is not liable for any requirement, binding or otherwise. LICENSE Software Diamonds permits the redistribution and use in source and binary forms, with or without modification, provided that the following conditions are met: 1 Redistributions of source code must retain the above copyright notice, this list of conditions and the following disclaimer. 2 Redistributions in binary form must reproduce the above copyright notice, this list of conditions and the following disclaimer in the documentation and/or other materials provided with the distribution. SOFTWARE DIAMONDS, http::www.softwarediamonds.com, PROVIDES THIS SOFTWARE 'AS IS' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL SOFTWARE DIAMONDS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING USE OF THIS SOFTWARE, EVEN IF ADVISED OF NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE POSSIBILITY OF SUCH DAMAGE. SEE ALSO Docs::Site_SVD::File_Package Test::STDmaker Title Page Software Version Description for File::Package - test load a pm and import symbs without eval and $@ misbehavoirs Revision: E Version: 0.06 Date: 2004/04/26 Prepared for: General Public Prepared by: SoftwareDiamonds.com Esupport@SoftwareDiamonds.comE Copyright: copyright © 2003 Software Diamonds Classification: NONE 1.0 SCOPE This paragraph identifies and provides an overview of the released files. 1.1 Identification This release, identified in 3.2, is a collection of Perl modules that extend the capabilities of the Perl language. 1.2 System overview One very useful test of the installation of a package is whether or not the package loaded. If it did not load, the reason it did not load is helpful diagnostics and may be used to programically (automatically) take corrective action. The load_package method attempts to capture any load problems by loading the package with a "require " under an eval and capturing all the "warn" and $@ messages. The error messages are returned with a warn instead of die so that the using program may take the appropriate action such as reporting the errors back to the author when used in test software or perhaps falling back on a system 'gzip' command when the 'Compress::Zlib' module fails to load. 1.3 Document overview. This document releases File::Package version 0.06 providing a description of the inventory, installation instructions and other information necessary to utilize and track this release. 3.0 VERSION DESCRIPTION All file specifications in this SVD use the Unix operating system file specification. 3.1 Inventory of materials released. This document releases the file File-Package-0.06.tar.gz found at the following repository(s): http://www.softwarediamonds/packages/ http://www.perl.com/CPAN/authors/id/S/SO/SOFTDIA/ Restrictions regarding duplication and license provisions are as follows: Copyright. copyright © 2003 Software Diamonds Copyright holder contact. 603 882-0846 Esupport@SoftwareDiamonds.comE License. Software Diamonds permits the redistribution and use in source and binary forms, with or without modification, provided that the following conditions are met: 1 Redistributions of source code, modified or unmodified must retain the above copyright notice, this list of conditions and the following disclaimer. 2 Redistributions in binary form must reproduce the above copyright notice, this list of conditions and the following disclaimer in the documentation and/or other materials provided with the distribution. SOFTWARE DIAMONDS, http://www.SoftwareDiamonds.com, PROVIDES THIS SOFTWARE 'AS IS' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL SOFTWARE DIAMONDS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING USE OF THIS SOFTWARE, EVEN IF ADVISED OF NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE POSSIBILITY OF SUCH DAMAGE. 3.2 Inventory of software contents The content of the released, compressed, archieve file, consists of the following files: file version date comment ------------------------------------------------------------ ------- ---------- ------------------------ lib/Docs/Site_SVD/File_Package.pm 0.06 2004/04/26 revised 0.05 MANIFEST 0.06 2004/04/26 generated, replaces 0.05 Makefile.PL 0.06 2004/04/26 generated, replaces 0.05 README 0.06 2004/04/26 generated, replaces 0.05 lib/File/Package.pm 1.16 2004/04/26 revised 1.15 t/File/Package.d 0.03 2004/04/26 revised 0.02 t/File/Package.pm 0.01 2004/04/10 unchanged t/File/Package.t 0.12 2004/04/26 revised 0.11 t/File/_File_/BadLoad.pm 0.01 2004/04/10 unchanged t/File/_File_/BadPackage.pm 0.01 2004/04/10 unchanged t/File/_File_/Hyphen-Test.pm 1.15 2004/04/10 unchanged t/File/_File_/Multi.pm 1.15 2004/04/10 unchanged t/File/Test/Tech.pm 1.21 2004/04/26 revised 1.17 t/File/Data/Secs2.pm 1.18 2004/04/26 revised 1.15 t/File/Data/SecsPack.pm 0.03 2004/04/26 new t/File/Data/Startup.pm 0.03 2004/04/26 new 3.3 Changes The file names from 0.05 were changed as follows: return if $file =~ s=lib/File/FileUtil.pm=lib/File/Package.pm=; return if $file =~ s=t/File/FileUtil/FileUtil.t=t/File/package.t=; Changes to past revisions are as follows: Test-TestUtil-0.01 Originated Test-TestUtil-0.02 Correct failure from Josts Smokehouse" test run t/Test/TestUtil/TestUtil....Bareword "fspec_dirs" not allowed while "strict subs" in use at /net/sunu991/disc1/.cpanplus/5.8.0/build/Test-TestUtil-0.01/blib/lib/Test/TestUtil.pm line 56. Changed line 56 from my @dirs = (fspec_dirs) ? $from_package->splitdir( $fspec_dirs ) : (); to my @dirs = ($fspec_dirs) ? $from_package->splitdir( $fspec_dirs ) : (); This error is troublesome since the test passed on my system using Active Perl under Microsoft NT. It should never have passed. This error is in a core method, *fspec2fspec*, that changes file specifications from one operating system to another operating system. This method has been in service unchanged for some time. Test-TestUtil-0.03 Correct failure from Josts Smokehouse" test run PERL_DL_NONLAZY=1 /usr/local/perl/bin/perl "-MExtUtils::Command::MM" "-e" "test_harness(0, 'blib/lib', 'blib/arch')" t/Test/TestUtil/TestUtil.t t/Test/TestUtil/TestUtil....# Test 18 got: '$VAR1 = ''; ' (t/Test/TestUtil/TestUtil.t at line 540 fail #17) # Expected: '$VAR1 = '\\=head1 Title Page The *pm2datah* method is not returning any data for Test 18. This will also cause the test of *pm2data*, test 19 to fail. The *pm2datah* is searching for the string "\n__DATA__\n". The "\n" character on Perl is a logical end of line character sequence. The "\n" end of line is different on Mr. Smokehouse's Unix operating system than on my Windows NT operating system. The test file was created under MSWin32 and uses a MSWin32 "\n". Under UNIX, *pm2datah* method will look for the Unix "\n" and there will not be any. Changed "\n__DATA__\n" to /[\012\015]__DATA__/. During the clean-up for CPAN, broke the *format_hash_table* method for tables in hash of hash format. Fixed the break, added test 29 to the *t/Test/TestUtil/TestUtil.t* test script for this feature, and added a discusssion of this feature in POD discription for *format_hash_table* Test-TestUtil-0.04 item our old friend visits again - DOS and UNIX text file incompatibility This impacts other modules. We have to examine all modules for this portability defect and correct any found defects. Correct failure from Josts Smokehouse" and Kingpin test runs. On Mr. Smokehouse's run email the got: VAR1 clearly showed extra white space line that is not present in the expected: VAR1. In Mr. Kingpin's run the got: VAR1 and expected: VAR1 look visually the same. However, the Unix found a difference(s) and failed the test. For Mr. Smokehouse's run: PERL_DL_NONLAZY=1 /usr/local/bin/perl "-MExtUtils::Command::MM" "-e" "test_harness(0, 'blib/lib', 'blib/arch')" t/Test/TestUtil/TestUtil.t t/Test/TestUtil/TestUtil....NOK 18# Test 18 got: '$VAR1 = '\\=head1 Title Page Software Version Description for File::Package - test load a pm and import symbs without eval and $@ misbehavoirs Revision: E [snip] (t/Test/TestUtil/TestUtil.t at line 565 fail #17) # Expected: '$VAR1 = '\\=head1 Title Page Software Version Description for File::Package - test load a pm and import symbs without eval and $@ misbehavoirs What we have before, was a totally "failure to communicate." aka Cool Hand Luke. VAR1 was empty. Now VAR1 has something. It is not completely dead. One probable cause is the Unix operating system must be producing two Unix \012 new lines for a Microsoft single newline \015\012. Without being able to examine the test with a debugger, the only way to verify this is to provide the fix and see if the problem goes away when this great group of testers try for the fourth time. Revised *fin* method to take a handle, change *pm2datah* method handle, *$fh*, to binary by adding a *binmode $fh* statement, and pass the actual thru the *fin* method for test 18. Use *fin($fh)* to read in the data for *pm2data*, test 19 Unit Under Test (UUT), instead of using the raw file handle. The *fin* method takes any \015\012 combination and changes it into the logical Perl new line, *"\n"*, for the current operating system. File-FileUtil-0.01 * At 02:44 AM 6/14/2003 +0200, Max Maischein wrote: A second thing that I would like you to reconsider is the naming of "Test::TestUtil" respectively "Test::Tech" - neither of those is descriptive of what the routines actually do or what the module implements. I would recommend renaming them to something closer to your other modules, maybe "Test::SVDMaker::Util" and "Test::SVDMaker::Tech", as some routines do not seem to be specific to the Test::-suite but rather general (format_array_table). Some parts (the "scrub" routines) might even better live in another module namespace, "Test::Util::ScrubData" or something like that. Broke away all the file related methods from Test::TestUtil and created this module File::FileUtil so the module name is more descriptive of the methods within the module. * Broke the smart nl code out of the fin method and made it is own separate method, smart_nl method. At 02:44 AM 6/14/2003 +0200, Max Maischein wrote: Perl, as Perl already does smart newline handling, (even though with the advent of 5.8 even Unix-people have to learn the word "binmode" now :-)) The only place where I see Perl does smart newline handling is the crlf IO displine introduce in Perl 5.6. The File::FileUtil has a use 5.001 so that 5.6 Perl built-ins cannot be used. Added comment to smart_nl that for users with 5.6 Perl that it may be better to use the built-in crlf IO discipline. * For the load_package method that uses a eval "require $package" to load the package, the $@ does not capture all the warnings and error messages, at least not with ActiveState Perl. Added code the captures also the warnings, by temporaily reassigning $SIG(__WARN__), and added these to the $@ error messages. * Added two new tests to verify the NOGO paths for the for the load_package method. One tests for load module failure looking for all the possilbe information on why the module did not load. The other verifies that the vocabulary is present after the loading the module. This information is very helpful when you must remote debug a load failure from CPAN testing whose is running on a different platform. File-FileUtil-0.02 Added the method *hex_dump*. File-FileUtil-0.03 test_lib2inc Returns to parent directory of the first t directory going up from the test script instead of the t directory. find_t_roots Added the function find_t_roots that returns the parent directory of all the directories in @INC File-Package-0.01 Removed the methods for loading a program module with the same name from the "File::FileUtil" module to their own module "File::Package" module. The module name is now much more descriptive of the routines in the module. File-Package-0.02 Replace the obsolete "File::FileUtil" with File::Packgage in the test script "t\File\package.t". File-Package-0.03 Added subroutine interfaces. Added @import input to load_packages method File-Package-0.04 Upgraded the 'tlib\Test\Tech' and changed the name of 'tlib\Data\strify' to 'tlib\Data\Secs2'. The new name is more self-explanatory. File-Package-0.05 The lastest build of Test::STDmaker expects the test library in the same directory as the test script. Coordiated with the lastest Test::STDmaker by moving the test library from tlib to t/File, the same directory as the test script and deleting the test library File::TestPath program module. File-Package-0.06 Added "Carp::longmess", that dumps the call stack, to the Carp::croak trap function. File-Package-0.07 Expanded the description. Under the Perl 5.6, Microsoft distribute, "Carp" program module, "import" sends warings out using "&Carp::carp" function as well as "Carp::croak" function. Adjust to also pick up these messages. 3.4 Adaptation data. This installation requires that the installation site has the Perl programming language installed. There are no other additional requirements or tailoring needed of configurations files, adaptation data or other software needed for this installation particular to any installation site. 3.5 Related documents. There are no related documents needed for the installation and test of this release. 3.6 Installation instructions. Instructions for installation, installation tests and installation support are as follows: Installation Instructions. To installed the release file, use the CPAN module pr PPM module in the Perl release or the INSTALL.PL script at the following web site: http://packages.SoftwareDiamonds.com Follow the instructions for the the chosen installation software. If all else fails, the file may be manually installed. Enter one of the following repositories in a web browser: http://www.softwarediamonds/packages/ http://www.perl.com/CPAN/authors/id/S/SO/SOFTDIA/ Right click on 'File-Package-0.06.tar.gz' and download to a temporary installation directory. Enter the following where $make is 'nmake' for microsoft windows; otherwise 'make'. gunzip File-Package-0.06.tar.gz tar -xf File-Package-0.06.tar perl Makefile.PL $make test $make install On Microsoft operating system, nmake, tar, and gunzip must be in the exeuction path. If tar and gunzip are not install, download and install unxutils from http://packages.softwarediamonds.com Prerequistes. None. Security, privacy, or safety precautions. None. Installation Tests. Most Perl installation software will run the following test script(s) as part of the installation: t/File/Package.t Installation support. If there are installation problems or questions with the installation contact 603 882-0846 Esupport@SoftwareDiamonds.comE 3.7 Possible problems and known errors There is still much work needed to ensure the quality of this module as follows: * State the functional requirements for each method including not only the GO paths but also what to expect for the NOGO paths * All the tests are GO path tests. Should add NOGO tests. * Add the requirements addressed as *# R: * comment to the tests 4.0 NOTES The following are useful acronyms: .d extension for a Perl demo script file .pm extension for a Perl Library Module .t extension for a Perl test script file POD Plain Old Documentation 2.0 SEE ALSO File::Package Docs::US_DOD::SVD