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A lesson in Perl Package Syntax

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I was given a perl program today, however running on my Fedora Core 5 install gave me the following error.

$ ./nameofcommand
Can't locate Term/ReadKey.pm in @INC (@INC contains: /usr/lib/perl5/site_perl/5.8.8/i386-linux-thread-multi
/usr/lib/perl5/site_perl/5.8.7/i386-linux-thread-multi /usr/lib/perl5/site_perl/5.8.6/i386-linux-thread-multi
/usr/lib/perl5/site_perl/5.8.5/i386-linux-thread-multi /usr/lib/perl5/site_perl/5.8.4/i386-linux-thread-multi
/usr/lib/perl5/site_perl/5.8.3/i386-linux-thread-multi /usr/lib/perl5/site_perl/5.8.8 /usr/lib/perl5/site_perl/5.8.7 /usr/lib/perl5/site_perl/5.8.6
/usr/lib/perl5/site_perl/5.8.5 /usr/lib/perl5/site_perl/5.8.4 /usr/lib/perl5/site_perl/5.8.3 /usr/lib/perl5/site_perl
/usr/lib/perl5/vendor_perl/5.8.8/i386-linux-thread-multi /usr/lib/perl5/vendor_perl/5.8.7/i386-linux-thread-multi
/usr/lib/perl5/vendor_perl/5.8.6/i386-linux-thread-multi /usr/lib/perl5/vendor_perl/5.8.5/i386-linux-thread-multi
/usr/lib/perl5/vendor_perl/5.8.4/i386-linux-thread-multi /usr/lib/perl5/vendor_perl/5.8.3/i386-linux-thread-multi /usr/lib/perl5/vendor_perl/5.8.8
/usr/lib/perl5/vendor_perl/5.8.7 /usr/lib/perl5/vendor_perl/5.8.6 /usr/lib/perl5/vendor_perl/5.8.5 /usr/lib/perl5/vendor_perl/5.8.4
/usr/lib/perl5/vendor_perl/5.8.3 /usr/lib/perl5/vendor_perl /usr/lib/perl5/5.8.8/i386-linux-thread-multi /usr/lib/perl5/5.8.8 .)
at ./nameofcommand line 28.

A quick check of the things I know about Perl.

$ rpm -qa | grep perl
perl-Digest-HMAC-1.01-14.2
perl-XML-Parser-2.34-6.1.2.2
perl-DBI-1.50-2.2
perl-Digest-SHA1-2.11-1.2
perl-URI-1.35-2.2
perl-Compress-Zlib-1.41-1.2.2
perl-HTML-Parser-3.51-1.FC5
perl-5.8.8-5
perl-Net-DNS-0.57-1
perl-HTML-Tagset-3.10-2.1
perl-Net-IP-1.25-1.fc5
perl-libwww-perl-5.805-1.1
perl-SGMLSpm-1.03ii-16.2
perl-String-CRC32-1.4-1.FC5

$ perl --version
This is perl, v5.8.8 built for i386-linux-thread-multi

$ cpan Term/ReadKey
Going to read /root/.cpan/sources/authors/01mailrc.txt.gz
CPAN: Compress::Zlib loaded ok
Going to read /root/.cpan/sources/modules/02packages.details.txt.gz
  Database was generated on Thu, 31 Aug 2006 11:32:19 GMT
CPAN: HTTP::Date loaded ok

  There's a new CPAN.pm version (v1.87) available!
  [Current version is v1.7602]
  You might want to try
    install Bundle::CPAN
    reload cpan
  without quitting the current session. It should be a seamless upgrade
  while we are running...

Going to read /root/.cpan/sources/modules/03modlist.data.gz
CPAN: Storable loaded ok
Going to write /root/.cpan/Metadata
Running make for T/T//T/Te/Term/ReadKey
CPAN: LWP::UserAgent loaded ok
Fetching with LWP:

http://cpan.mirrors.ilisys.com.au/authors/id/T/T//T/Te/Term/ReadKey

Fetching with LWP:

http://cpan.mirrors.ilisys.com.au/authors/id/T/T//T/Te/Term/ReadKey.gz

Trying with "/usr/bin/links -source" to get

http://cpan.mirrors.ilisys.com.au/authors/id/T/T//T/Te/Term/ReadKey

CPAN: Digest::MD5 loaded ok

Trying with "/usr/bin/links -source" to get

http://cpan.mirrors.ilisys.com.au/authors/id/T/T//T/Te/Term/CHECKSUMS

'glob' trapped by operation mask at (eval 25) line 1.
 at /usr/lib/perl5/5.8.8/CPAN.pm line 4265
        CPAN::Distribution::MD5_check_file('CPAN::Distribution=HASH(0xaeee4d4)', '/root/.cpan/sources/authors/id/T/T/T/Te/Term/CHECKSUMS') called at /usr/lib/perl5/5.8.8/CPAN.pm line 4246
        CPAN::Distribution::verifyMD5('CPAN::Distribution=HASH(0xaeee4d4)') called at /usr/lib/perl5/5.8.8/CPAN.pm line 3894
        CPAN::Distribution::get('CPAN::Distribution=HASH(0xaeee4d4)') called at /usr/lib/perl5/5.8.8/CPAN.pm line 4463
        CPAN::Distribution::make('CPAN::Distribution=HASH(0xaeee4d4)') called at /usr/lib/perl5/5.8.8/CPAN.pm line 4703
        CPAN::Distribution::test('CPAN::Distribution=HASH(0xaeee4d4)') called at /usr/lib/perl5/5.8.8/CPAN.pm line 4808
        CPAN::Distribution::install('CPAN::Distribution=HASH(0xaeee4d4)') called at /usr/lib/perl5/5.8.8/CPAN.pm line 2137
        CPAN::Shell::rematein('CPAN::Shell', 'install', 'Term/ReadKey') called at /usr/lib/perl5/5.8.8/CPAN.pm line 2164
        CPAN::Shell::install('CPAN::Shell', 'Term/ReadKey') called at /usr/bin/cpan line 202

Time to IM my friend and Perl expert Tony. I can obviously read Perl ok, have even worked with Perl CGI many many years ago, but this will be some configuration syntax I’m just not familar with because I don’t develop in Perl.

In summary,Tony’s (Mr Perl for today) tips we:

  • perl -e ‘for (@INC) { printf “%d %sn”, $i++, $_} ‘
  • PERL5LIB env variable
  • or -I command line switch, syntax is -Idirlist dirlist is a colon-separated list of one or more directories to INC
  • but it might need term::readkey perl uses keyword :: package or similar

And indeed it was the syntax. Now some enterprising perl person could rather then just saying Can’t locate Term/ReadKey.pm , could add try cpan Term::ReadKey to install this package.

$ cpan Term::ReadKey
CPAN: Storable loaded ok
Going to read /root/.cpan/Metadata
  Database was generated on Thu, 31 Aug 2006 11:32:19 GMT
Running install for module Term::ReadKey
Running make for J/JS/JSTOWE/TermReadKey-2.30.tar.gz
CPAN: LWP::UserAgent loaded ok
Fetching with LWP:

http://cpan.mirrors.ilisys.com.au/authors/id/J/JS/JSTOWE/TermReadKey-2.30.tar.gz

CPAN: Digest::MD5 loaded ok
Fetching with LWP:

http://cpan.mirrors.ilisys.com.au/authors/id/J/JS/JSTOWE/CHECKSUMS

Checksum for /root/.cpan/sources/authors/id/J/JS/JSTOWE/TermReadKey-2.30.tar.gz ok
Scanning cache /root/.cpan/build for sizes
TermReadKey-2.30/
TermReadKey-2.30/genchars.pl
TermReadKey-2.30/Makefile.PL
TermReadKey-2.30/Configure.pm
TermReadKey-2.30/test.pl
TermReadKey-2.30/ReadKey.pm
TermReadKey-2.30/META.yml
TermReadKey-2.30/ReadKey.xs
TermReadKey-2.30/ppport.h
TermReadKey-2.30/MANIFEST
TermReadKey-2.30/README

  CPAN.pm: Going to build J/JS/JSTOWE/TermReadKey-2.30.tar.gz

Checking if your kit is complete...
Looks good
Writing Makefile for Term::ReadKey
cp ReadKey.pm blib/lib/Term/ReadKey.pm
AutoSplitting blib/lib/Term/ReadKey.pm (blib/lib/auto/Term/ReadKey)
/usr/bin/perl -I/usr/lib/perl5/5.8.8 genchars.pl

Writing termio/termios section of cchars.h... Done.
Checking for sgtty...
        Sgtty NOT found.
Writing sgtty section of cchars.h... Done.
/usr/bin/perl /usr/lib/perl5/5.8.8/ExtUtils/xsubpp -noprototypes -typemap /usr/lib/perl5/5.8.8/ExtUtils/typemap  ReadKey.xs > ReadKey.xsc && mv ReadKey.xsc ReadKey.c
gcc -c   -D_REENTRANT -D_GNU_SOURCE -fno-strict-aliasing -pipe -Wdeclaration-after-statement -I/usr/local/include -D_LARGEFILE_SOURCE -D_FILE_OFFSET_BITS=64 -I/usr/include/gdbm -O2 -g -pipe -Wall -Wp,-D_FORTIFY_SOURCE=2 -fexceptions -fstack-protector --param=ssp-buffer-size=4 -m32 -march=i386 -mtune=generic -fasynchronous-unwind-tables   -DVERSION="2.30" -DXS_VERSION="2.30" -fPIC "-I/usr/lib/perl5/5.8.8/i386-linux-thread-multi/CORE"   ReadKey.c
In file included from ReadKey.xs:6:
ppport.h:230:1: warning: "PERL_UNUSED_DECL" redefined
In file included from ReadKey.xs:4:
/usr/lib/perl5/5.8.8/i386-linux-thread-multi/CORE/perl.h:163:1: warning: this is the location of the previous definition
In file included from ReadKey.xs:375:
cchars.h: In function ‘XS_Term__ReadKey_GetControlChars’:
cchars.h:244: warning: unused variable ‘i’
ReadKey.xs: In function ‘ReadMode’:
ReadKey.xs:770: warning: unused variable ‘Perl___notused’
ReadKey.c: In function ‘XS_Term__ReadKey_SetTerminalSize’:
ReadKey.c:1999: warning: unused variable ‘targ’
Running Mkbootstrap for Term::ReadKey ()
chmod 644 ReadKey.bs
rm -f blib/arch/auto/Term/ReadKey/ReadKey.so
gcc  -shared -L/usr/local/lib ReadKey.o  -o blib/arch/auto/Term/ReadKey/ReadKey.so      
        

chmod 755 blib/arch/auto/Term/ReadKey/ReadKey.so
cp ReadKey.bs blib/arch/auto/Term/ReadKey/ReadKey.bs
chmod 644 blib/arch/auto/Term/ReadKey/ReadKey.bs
Manifying blib/man3/Term::ReadKey.3pm
  /usr/bin/make  -- OK
Running make test
PERL_DL_NONLAZY=1 /usr/bin/perl "-Iblib/lib" "-Iblib/arch" -w test.pl
1 .. 8
ok 1
ok 2
ok 3
ok 4
ok 5
ok 6
ok 7
ok 8
  /usr/bin/make test -- OK
Running make install
Installing /usr/lib/perl5/site_perl/5.8.8/i386-linux-thread-multi/auto/Term/ReadKey/ReadKey.so
Installing /usr/lib/perl5/site_perl/5.8.8/i386-linux-thread-multi/auto/Term/ReadKey/ReadKey.bs
Files found in blib/arch: installing files in blib/lib into architecture dependent library tree
Installing /usr/lib/perl5/site_perl/5.8.8/i386-linux-thread-multi/auto/Term/ReadKey/autosplit.ix
Installing /usr/lib/perl5/site_perl/5.8.8/i386-linux-thread-multi/Term/ReadKey.pm
Installing /usr/share/man/man3/Term::ReadKey.3pm
Writing /usr/lib/perl5/site_perl/5.8.8/i386-linux-thread-multi/auto/Term/ReadKey/.packlist
Appending installation info to /usr/lib/perl5/5.8.8/i386-linux-thread-multi/perllocal.pod
  /usr/bin/make install  -- OK