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lib/Advanced/Config/Options.pm  view on Meta::CPAN

=head1 The Read Options

In most cases the defaults should do nicely for you.  But when you share config
files between applications, you may not have any control over the config file's
format.  This may also apply if your organization requires a specific format
for its config files.

So this section deals with the options you can use to override how it parses and
interprets the config file when it is loaded into memory.  None of these options
below allows leading or trailing spaces in the option's value.  And if any are
found, they will be automatically trimmed off before their value is used.
Internal spaces are OK when non-numeric values are expected.  In most cases
values with a length of B<0> or B<undef> are not allowed.

Just be aware that some combinations of I<Read> options may result in this
module being unable to parse the config file.  If you encounter such a
combination open a CPAN ticket and I'll see what I can do about it.  But some
combinations may just be too ambiguous to handle.

Also note that some I<Read> options have B<left> and B<right> variants.  These
options are used in pairs and both must anchor the target in order for the rule
to be applied to it.  These start/end anchors can be set to the same string or
different strings.  Your choice.

=head2 Tag(s) Best Set in Call to the Constructor new().

While not required to set these options during the call to B<new>, changing
their settings later on can cause unexpected issues if you are not careful.

But it's still recommended that most I<Read> Options be set during the call to
B<new> to avoid having to keep on resetting them all the time and limit these
later changes to handle exceptions to your defaults.

=over 4

B<tag_case> - Config files are made up of tag/value pairs.  This option controls
whether the tags are case sensitive (B<0>, the default) or case insensitive
(B<1>).  IE do tags B<ABC> and B<abc> represent the same tag or not?  So if set,
all tags are assumed to be in lower case for the get/set methods!

=back

=head2 Generic Read Options

These options are also usually set during the call to B<new>, but setting them
later on doesn't produce strange behavior if you change the settings later on.

=over 4

B<croak> - This controls what happens when a function hits an unexpected error
while parsing the config file.  Set to B<0> to return an error code (default),
B<-1> to return an error code and print a warning to your screen, B<1> to call
die and terminate your program.

B<export> - Tells if we should export all tag/value pairs to perl's %ENV hash
or not.  The default is B<0> for I<No>.  Set to B<1> if you want this to happen.
But if set, it reverses the meaning of the B<export_lbl> option defined later
on.

B<use_utf8> - Defaults to B<0>.  Set to B<1> if the config file was created
using utf8 encoding.  (IE Unicode or Wide Characters.)  Guessing this
setting wrong means the file will be unusable as a config file.

B<disable_quotes> - Defaults to B<0>.  Set to B<1> if you want to disallow
the stripping of balanced quotes in your config files.

B<disable_variables> - Defaults to B<0>.  Set to B<1> if you want to disable
variable expansion in your config files when they are loaded into memory.

B<disable_variable_modifiers> - Defaults to B<0>.  Set to B<1> if you want to
disable this feature.  See L<http://wiki.bash-hackers.org/syntax/pe> for more
details.  This feature allows you to put logic into your config files via
your variable definitions.  Automatically disabled when variables are
disabled.  Useful when you put a lot of special chars into your variable
names.

B<disable_decryption> - Defaults to B<0>.  Set to B<1> if you want to disable
decrypting values that have been marked as encrypted.  If a variable references
an encrypted value while disable_decription is active, that variable isn't
expanded.

=cut 

# B<enable_backquotes> - Defaults to B<0>.  Set to B<1> if you want to enable
# this feature.  It's disabled by default since it can be considered a security
# hole if an unauthorized user can modify your config file or your code.

=pod

B<trap_recursion> - Defaults to B<0>.  Set to B<1> if you want to treat
recursion as a fatal error when loading a config file.  By default it just
ignores the recursion request to prevent infinite loops.

B<source_cb_opts> - A work area for holding values between calls to the
callback function.  This is expected to be a hash reference to provide any
needed configuration values needed to parse the next config file.  This way
you can avoid global variables.  Defaults to an empty hash reference.

B<source_cb> - An optional callback routine called each time your config file
sources in another config file.  It's main use is when the I<Read Options>
and/or I<Date Format Options> required to parse each config file change between
files.  It's automatically called right before the sourced in file is opened up
for parsing.

Once the new file is sourced in, it inherits most of the options currently used
unless you override them.  The only ones not inherited deal with decryption.

Here is the callback function's expected definition:

  my ($rOpts, $dOpts) = source_callback_func ($file[, $cbOpts]);

  $file --> The file being sourced in.

  $cbOpts --> A hash reference containing values needed by your callback
              function to decide what options are required to source in the
              requested file.  You may update the contents of this hash to
              preserve info between calls.  This module will "never" examine
              the contents of this hash!

  $rOpts --> A reference to the "Read Options" hash used to parse the file
             you want to source in.  Returns "undef" if the options don't

lib/Advanced/Config/Options.pm  view on Meta::CPAN

      # Can't use on unix due to sudo issue returns wrong user.
      $user = getlogin () || "??";
   }
   DBUG_RETURN ($user);
}

# ==============================================================
# A stub of the source callback function ...
sub _source_callback_stub
{
   DBUG_ENTER_FUNC ( @_ );
   my $file = shift;
   my $opts = shift;
   DBUG_RETURN ( undef, undef );
}


# ==============================================================
# A stub of the encryption/decryption callback function ...
sub _encryption_callback_stub
{
   DBUG_MASK_NEXT_FUNC_CALL (2);   # Mask $value!
   DBUG_ENTER_FUNC ( @_ );
   my $mode   = shift;
   my $tag    = shift;
   my $value  = shift;   # Clear text sensitive value ...
   my $file   = shift;
   my $cbOpts = shift;
   DBUG_MASK ( 0 );
   DBUG_RETURN ( $value );
}


# ==============================================================
# Initialize the global hashes with their default values ...
BEGIN
{
   DBUG_ENTER_FUNC ();

   # ---------------------------------------------------------------------
   # Make sure no hash value is undef !!!
   # ---------------------------------------------------------------------

   # You can only add to this list, you can't remove anything from it!
   # See should_we_hide_sensitive_data () on how this list is used.
   DBUG_PRINT ("INFO", "Initializing the tag patterns to hide from fish ...");
   push ( @hide_from_fish, "password" );
   push ( @hide_from_fish, "pass" );
   push ( @hide_from_fish, "pwd" );

   # ---------------------------------------------------------------------

   DBUG_PRINT ("INFO", "Initializing the READ options global hash ...");
   # Should always be set in the constructor ...
   $default_read_opts{tag_case}   = 0;         # Case sensitive tags.

   # The generic options ...
   my %src_empty;
   $default_read_opts{croak}      = 0;         # Don't croak by default.
   $default_read_opts{export}     = 0;         # Don't export any tag/val pairs.
   $default_read_opts{use_utf8}   = 0;         # Doesn't support utf8/Unicode/Wide Chars.
   $default_read_opts{disable_quotes}     = 0; # Don't disable balanced quotes.
   $default_read_opts{disable_variables}  = 0; # Don't disable variables!
   $default_read_opts{disable_variable_modifiers} = 0; # Don't disable variable modifiers!
   $default_read_opts{disable_decryption} = 0; # Don't disable decryption!
 # $default_read_opts{enable_backquotes}  = 0; # Don't allow random command execution.
   $default_read_opts{trap_recursion}     = 0; # Recursion is ignored, not fatal
   $default_read_opts{source_cb}  = __PACKAGE__->can ("_source_callback_stub");
   $default_read_opts{source_cb_opts} = \%src_empty;

   # The file parsing options ...
   $default_read_opts{assign}          = '=';   # The assignment operator
   $default_read_opts{comment}         = '#';   # The comment symbol
   $default_read_opts{source}          = '.';   # The file source symbol
   $default_read_opts{section_left}    = '[';   # The start section string
   $default_read_opts{section_right}   = ']';   # The end section string
   $default_read_opts{variable_left}   = '${';  # The start variable string
   $default_read_opts{variable_right}  = '}';   # The end variable string

   # Unlikely default values due to security concerns.
   # $default_read_opts{backquote_left}  = '`'x101;  # The start backquote string
   # $default_read_opts{backquote_right} = '`'x102;  # The end backquote string

   # The quote chars ... (Special case doesn't work for anything else.)
   # See  using_default_quotes()  if this changes ...
   $default_read_opts{quote_left} = $default_read_opts{quote_right} = "['\"]";

   # The tag/value modifiers.  These labels are found inside the comments!
   $default_read_opts{export_lbl}  = "EXPORT";    # Label for a single %ENV.
   $default_read_opts{hide_lbl}    = "HIDE";      # Mark as sensitive.
   $default_read_opts{encrypt_lbl} = "ENCRYPT";   # Pending encryption.
   $default_read_opts{decrypt_lbl} = "DECRYPT";   # Already encrypted.
   $default_read_opts{source_file_section_lbl} = "DEFAULT";  # Override default.

   # The Encrypt/Decrypt options ... (Encode/Decode)
   my %empty_encrypt;
   $default_read_opts{alias}               = "";
   $default_read_opts{pass_phrase}         = "";
   $default_read_opts{inherit_pass_phrase} = 0;
   $default_read_opts{encrypt_by_user}     = 0;
   $default_read_opts{encrypt_cb}      = __PACKAGE__->can ("_encryption_callback_stub");
   $default_read_opts{encrypt_cb_opts} = \%empty_encrypt;

   # Special undocumented test prog option for overriding fish in parse_line().
   $default_read_opts{dbug_test_use_case_parse_override} = 0;  # Always off.

   # Special undocumented test prog option for overriding fish in read_config().
   $default_read_opts{dbug_test_use_case_hide_override} = 0;   # Always off.


   # ---------------------------------------------------------------------

   DBUG_PRINT ("INFO", "Initializing the GET options global hash ...");
   # Should always be set in the constructor ...
   $default_get_opts{inherit} = 0;        # Can inherit from the parent section.

   # The generic options ... Who cares where set!
   $default_get_opts{required}  = 0;         # Return undef by default.
   $default_get_opts{vcase}     = 0;         # Case of the value. (0 = as is)
   $default_get_opts{split_pattern} = qr /\s+/;  # Space separated lists.