B::Lint(3)             Perl Programmers Reference Guide             B::Lint(3)

       B::Lint - Perl lint

       perl -MO=Lint[,OPTIONS] foo.pl

       The B::Lint module is equivalent to an extended version of the -w
       option of perl. It is named after the program lint which carries out a
       similar process for C programs.

       Option words are separated by commas (not whitespace) and follow the
       usual conventions of compiler backend options. Following any options
       (indicated by a leading -) come lint check arguments. Each such
       argument (apart from the special all and none options) is a word
       representing one possible lint check (turning on that check) or is no-
       foo (turning off that check). Before processing the check arguments, a
       standard list of checks is turned on. Later options override earlier
       ones. Available options are:

       context Produces a warning whenever an array is used in an implicit
               scalar context. For example, both of the lines

                   $foo = length(@bar);
                   $foo = @bar;
               will elicit a warning. Using an explicit B<scalar()> silences the
               warning. For example,

                   $foo = scalar(@bar);

       implicit-read and implicit-write
               These options produce a warning whenever an operation
               implicitly reads or (respectively) writes to one of Perl's
               special variables.  For example, implicit-read will warn about


               and implicit-write will warn about these:


               Both implicit-read and implicit-write warn about this:

                   for (@a) { ... }

               This option warns whenever $_ is used either explicitly
               anywhere or as the implicit argument of a print statement.

               This option warns on each use of any variable, subroutine or
               method name that lives in a non-current package but begins with
               an underscore ("_"). Warnings aren't issued for the special
               case of the single character name "_" by itself (e.g. $_ and

               This option warns whenever an undefined subroutine is invoked.
               This option will only catch explicitly invoked subroutines such
               as foo() and not indirect invocations such as &$subref() or
               $obj->meth(). Note that some programs or modules delay
               definition of subs until runtime by means of the AUTOLOAD

               This option warns whenever one of the regexp variables $', $&
               or $' is used. Any occurrence of any of these variables in your
               program can slow your whole program down. See the perlre
               manpage for details.

       all     Turn all warnings on.

       none    Turn all warnings off.

       -u Package
               Normally, Lint only checks the main code of the program
               together with all subs defined in package main. The -u option
               lets you include other package names whose subs are then
               checked by Lint.

       This is only a very preliminary version.

       Malcolm Beattie, mbeattie@sable.ox.ac.uk.

3rd Berkeley Distribution    perl 5.005, patch 02                   B::Lint(3)