debian man page for string::format

Format(3pm)						User Contributed Perl Documentation					       Format(3pm)

NAME
       String::Format - sprintf-like string formatting capabilities with arbitrary format definitions

ABSTRACT
       String::Format allows for sprintf-style formatting capabilities with arbitrary format definitions

SYNOPSIS
	 use String::Format;

	 my %fruit = (
	       'a' => "apples",
	       'b' => "bannanas",
	       'g' => "grapefruits",
	       'm' => "melons",
	       'w' => "watermelons",
	 );

	 my $format = "I like %a, %b, and %g, but not %m or %w.";

	 print stringf($format, %fruit);

	 # prints:
	 # I like apples, bannanas, and grapefruits, but not melons or watermelons.

DESCRIPTION
       String::Format lets you define arbitrary printf-like format sequences to be expanded.  This module would be most useful in configuration
       files and reporting tools, where the results of a query need to be formatted in a particular way.  It was inspired by mutt's index_format
       and related directives (see <URL:http://www.mutt.org/doc/manual/manual-6.html#index_format>).

FUNCTIONS
   stringf
       String::Format exports a single function called stringf.  stringf takes two arguments:  a format string (see FORMAT STRINGS, below) and a
       reference to a hash of name => value pairs.  These name => value pairs are what will be expanded in the format string.

FORMAT STRINGS
       Format strings must match the following regular expression:

	 qr/
	    (%		   # leading '%'
	     (-)?	   # left-align, rather than right
	     (d*)?	   # (optional) minimum field width
	     (?:.(d*))?  # (optional) maximum field width
	     ({.*?})?	   # (optional) stuff inside
	     (S)	   # actual format character
	    )/x;

       If the escape character specified does not exist in %args, then the original string is used.  The alignment, minimum width, and maximum
       width options function identically to how they are defined in sprintf(3) (any variation is a bug, and should be reported).

       Note that Perl's sprintf definition is a little more liberal than the above regex; the deviations were intentional, and all deal with
       numeric formatting (the #, 0, and + leaders were specifically left out).

       The value attached to the key can be a scalar value or a subroutine reference; if it is a subroutine reference, then anything between the
       '{' and '}' ($5 in the above regex) will be passed as $_[0] to the subroutine reference.  This allows for entries such as this:

	 %args = (
	     d => sub { POSIX::strftime($_[0], localtime) },
	 );

       Which can be invoked with this format string:

	 "It is %{%M:%S}d right now, on %{%A, %B %e}d."

       And result in (for example):

	 It is 17:45 right now, on Monday, February 4.

       Note that since the string is passed unmolested to the subroutine reference, and strftime would Do The Right Thing with this data, the
       above format string could be written as:

	 "It is %{%M:%S right now, on %A, %B %e}d."

       By default, the formats 'n', 't', and '%' are defined to be a newline, tab, and '%', respectively, if they are not already defined in the
       hashref of arguments that gets passed it.  So we can add carriage returns simply:

	 "It is %{%M:%S right now, on %A, %B %e}d.%n"

       Because of how the string is parsed, the normal "
" and "	" are turned into two characters each, and are not treated as a newline and
       tab.  This is a bug.

FACTORY METHOD
       String::Format also supports a class method, named stringfactory, which will return reference to a "primed" subroutine.	stringfatory
       should be passed a reference to a hash of value; the returned subroutine will use these values as the %args hash.

	 my $self = Some::Groovy::Package->new($$, $<, $^T);
	 my %formats = (
	       'i' => sub { $self->id	   },
	       'd' => sub { $self->date    },
	       's' => sub { $self->subject },
	       'b' => sub { $self->body    },
	 );
	 my $index_format = String::Format->stringfactory(\%formats);

	 print $index_format->($format1);
	 print $index_format->($format2);

       This subroutine reference can be assigned to a local symbol table entry, and called normally, of course:

	 *reformat = String::Format->stringfactory(\%formats);

	 my $reformed = reformat($format_string);

LICENSE
       "String::Format" is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published
       by the Free Software Foundation; version 2.

AUTHOR
       darren chamberlain <darren@cpan.org>

perl v5.10.1							    2009-05-17							       Format(3pm)