SYNOPSIS
# non-OO
use Lintian::Output qw(:messages);
$Lintian::Output::GLOBAL->verbosity_level(1);
msg("Something interesting");
v_msg("Something less interesting");
debug_msg(3, "Something very specific");
# OO
use Lintian::Output;
my $out = Lintian::Output->new;
$out->verbosity_level(-1);
$out->msg("Something interesting");
$out->v_msg("Something less interesting");
$out->debug_msg(3, "Something very specific");
DESCRIPTION
Lintian::Output is used for all interaction between lintian and the user. It is designed to be easily extensible via subclassing.To simplify usage in the most common cases, many Lintian::Output methods can be used as class methods and will therefor automatically use the object $Lintian::Output::GLOBAL unless their first argument "isa('Lintian::Output')".
ACCESSORS
The following fields define the behaviours of Lintian::Output.- verbosity_level
- Determine how verbose the output should be. ``0'' is the default value (tags and msg only), ``-1'' is quiet (tags only) and ``1'' is verbose (tags, msg and v_msg).
- debug
- If set to a positive integer, will enable all debug messages issued with a level lower or equal to its value.
- color
-
Can take the values ``never'', ``always'', ``auto'' or ``html''.
Whether to colorize tags based on their severity. The default is ``never'', which never uses color. ``always'' will always use color, ``auto'' will use color only if the output is going to a terminal.
``html'' will output HTML <span> tags with a color style attribute (instead of ANSI color escape sequences).
- stdout
- I/O handle to use for output of messages and tags. Defaults to "\*STDOUT".
- stderr
- I/O handle to use for warnings. Defaults to "\*STDERR".
- showdescription
- Whether to show the description of a tag when printing it.
- issuedtags
- Hash containing the names of tags which have been issued.
- tag_display_limit
- Get/Set the number of times a tag is emitted per processable.
CLASS/INSTANCE METHODS
These methods can be used both with and without an object. If no object is given, they will fall back to the $Lintian::Output::GLOBAL object.- "msg(@args)"
- Will output the strings given in @args, one per line, each line prefixed with 'N: '. Will do nothing if verbosity_level is less than 0.
- "v_msg(@args)"
- Will output the strings given in @args, one per line, each line prefixed with 'N: '. Will do nothing unless verbosity_level is greater than 0.
- "debug_msg($level, @args)"
-
$level should be a positive integer.
Will output the strings given in @args, one per line, each line prefixed with 'N: '. Will do nothing unless debug is set to a positive integer >= $level.
- "warning(@args)"
- Will output the strings given in @args on stderr, one per line, each line prefixed with 'warning: '.
- "perf_log(@args)"
-
Like ``v_msg'', except output is possibly sent to a dedicated log
file.
Will output the strings given in @args, one per line. The lines will not be prefixed. Will do nothing unless perf_debug is set to a positive integer.
- "delimiter()"
-
Gives back a string that is usable for separating messages in the output.
Note: This does not print anything, it just gives back the string, use
with one of the methods above, e.g.
v_msg('foo', delimiter(), 'bar'); - "issued_tag($tag_name)"
- Indicate that the named tag has been issued. Returns a boolean value indicating whether the tag had previously been issued by the object.
- "string($lead, @args)"
- TODO: Is this part of the public interface?
INSTANCE METHODS FOR CONTEXT-AWARE OUTPUT
The following methods are designed to be called at specific points during program execution and require very specific arguments. They can only be called as instance methods.- "print_tag($pkg_info, $tag_info, $extra, $override)"
- Print a tag. The first two arguments are hash reference with the information about the package and the tag, $extra is the extra information for the tag (if any) as an array reference, and $override is either undef if the tag is not overridden or the override for this tag. Called from Lintian::Tags::tag().
- "print_start_pkg($pkg_info)"
- Called before lintian starts to handle each package. The version in Lintian::Output uses v_msg() for output. Called from Tags::select_pkg().
- "print_start_pkg($pkg_info)"
- Called after lintian is finished with a package. The version in Lintian::Output does nothing. Called from Lintian::Tags::file_start() and Lintian::Tags::file_end().
INSTANCE METHODS FOR SUBCLASSING
The following methods are only intended for subclassing and are only available as instance methods. The methods mentioned in ``CLASS/INSTANCE METHODS'' usually only check whether they should do anything at all (according to the values of verbosity_level and debug) and then call one of the following methods to do the actual printing. Almost all of them finally call _print() to do that. This convoluted scheme is necessary to be able to use the methods above as class methods and still make the behaviour overridable in subclasses.- "_message(@args)"
- Called by msg(), v_msg(), and debug_msg() to print the message.
- "_warning(@args)"
- Called by warning() to print the warning.
- "_print($stream, $lead, @args)"
-
Called by _message(), _warning(), and print_tag() to do
the actual printing.
If you override these three methods, you can change the calling convention for this method to pretty much whatever you want.
The version in Lintian::Output prints the strings in @args, one per line, each line preceded by $lead to the I/O handle given in $stream.
- "_delimiter()"
- Called by delimiter().
- "_do_color()"
- Called by print_tag() to determine whether to produce colored output.
- "_quote_print($string)"
- Called to quote a string. By default it will replace all non-printables with ``?''. Sub-classes can override it if they allow non-ascii printables etc.
CLASS METHODS
- "_global_or_object(@args)"
- If $args[0] is a object which satisfies "isa('Lintian::Output')" returns @args, otherwise returns "($Lintian::Output::GLOBAL, @_)".
EXPORTS
Lintian::Output exports nothing by default, but the following export tags are available:- :messages
- Exports all the methods in ``CLASS/INSTANCE METHODS''
- :util
- Exports all the methods in ``CLASS METHODS''