b::lint(3pm)
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 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 ssccaallaarr(()) 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 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. Typical 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 anywhere 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 definition of subs until runtime by means of the AUTOLOAD mechanism.
- 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.