B::Lint

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



NAME
       B::Lint - Perl lint

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

DESCRIPTION
       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.

OPTIONS AND LINT CHECKS
       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 argu-
       ment (apart from the special all and none options) is a word represent-
       ing one possible lint check (turning on that check) or is no-foo (turn-
       ing 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 scalar() silences the
               warning. For example,

                   $foo = scalar(@bar);

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

                   /foo/;

               and implicit-write will warn about these:

                   s/foo/bar/;

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

                   for (@a) { ... }

       bare-subs
               This option warns whenever a bareword is implicitly quoted, but
               is also the name of a subroutine in the current package. Typi-
               cal mistakes that it will trap are:

                   use constant foo => 'bar';
                   @a = ( foo => 1 );
                   $b{foo} = 2;

               Neither of these will do what a naive user would expect.

       dollar-underscore
               This option warns whenever $_ is used either explicitly any-
               where or as the implicit argument of a print statement.

       private-names
               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
               @_).

       undefined-subs
               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 defi-
               nition of subs until runtime by means of the AUTOLOAD mecha-
               nism.

       regexp-variables
               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 perlre for
               details.

       all     Turn all warnings on.

       none    Turn all warnings off.

NON LINT-CHECK OPTIONS
       -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.

BUGS
       This is only a very preliminary version.

       This module doesn't work correctly on thread-enabled perls.

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



perl v5.8.6                       2001-09-21                        B::Lint(3)