Provided by: libtext-recordparser-perl_1.6.3-1_all 
NAME
Text::RecordParser - read record-oriented files
SYNOPSIS
use Text::RecordParser;
# use default record (\n) and field (,) separators
my $p = Text::RecordParser->new( $file );
# or be explicit
my $p = Text::RecordParser->new({
filename => $file,
field_separator => "\t",
});
$p->filename('foo.csv');
# Split records on two newlines
$p->record_separator("\n\n");
# Split fields on tabs
$p->field_separator("\t");
# Skip lines beginning with hashes
$p->comment( qr/^#/ );
# Trim whitespace
$p->trim(1);
# Use the fields in the first line as column names
$p->bind_header;
# Get a list of the header fields (in order)
my @columns = $p->field_list;
# Extract a particular field from the next row
my ( $name, $age ) = $p->extract( qw[name age] );
# Return all the fields from the next row
my @fields = $p->fetchrow_array;
# Define a field alias
$p->set_field_alias( name => 'handle' );
# Return all the fields from the next row as a hashref
my $record = $p->fetchrow_hashref;
print $record->{'name'};
# or
print $record->{'handle'};
# Return the record as an object with fields as accessors
my $object = $p->fetchrow_object;
print $object->name; # or $object->handle;
# Get all data as arrayref of arrayrefs
my $data = $p->fetchall_arrayref;
# Get all data as arrayref of hashrefs
my $data = $p->fetchall_arrayref( { Columns => {} } );
# Get all data as hashref of hashrefs
my $data = $p->fetchall_hashref('name');
DESCRIPTION
This module is for reading record-oriented data in a delimited text file. The most common
example have records separated by newlines and fields separated by commas or tabs, but
this module aims to provide a consistent interface for handling sequential records in a
file however they may be delimited. Typically this data lists the fields in the first
line of the file, in which case you should call "bind_header" to bind the field name (or
not, and it will be called implicitly). If the first line contains data, you can still
bind your own field names via "bind_fields". Either way, you can then use many methods to
get at the data as arrays or hashes.
METHODS
new
This is the object constructor. It takes a hash (or hashref) of arguments. Each argument
can also be set through the method of the same name.
· filename
The path to the file being read. If the filename is passed and the fh is not, then it
will open a filehandle on that file and sets "fh" accordingly.
· comment
A compiled regular expression identifying comment lines that should be skipped.
· data
The data to read.
· fh
The filehandle of the file to read.
· field_separator | fs
The field separator (default is comma).
· record_separator | rs
The record separator (default is newline).
· field_filter
A callback applied to all the fields as they are read.
· header_filter
A callback applied to the column names.
· trim
Boolean to enable trimming of leading and trailing whitespace from fields (useful if
splitting on whitespace only).
See methods for each argument name for more information.
Alternately, if you supply a single argument to "new", it will be treated as the
"filename" argument.
bind_fields
$p->bind_fields( qw[ name rank serial_number ] );
Takes an array of field names and memorizes the field positions for later use. If the
input file has no header line but you still wish to retrieve the fields by name (or even
if you want to call "bind_header" and then give your own field names), simply pass in the
an array of field names you wish to use.
Pass in an empty array reference to unset:
$p->bind_field( [] ); # unsets fields
bind_header
$p->bind_header;
my $name = $p->extract('name');
Takes the fields from the next row under the cursor and assigns the field names to the
values. Usually you would call this immediately after opening the file in order to bind
the field names in the first row.
comment
$p->comment( qr/^#/ ); # Perl-style comments
$p->comment( qr/^--/ ); # SQL-style comments
Takes a regex to apply to a record to see if it looks like a comment to skip.
data
$p->data( $string );
$p->data( \$string );
$p->data( @lines );
$p->data( [$line1, $line2, $line3] );
$p->data( IO::File->new('<data') );
Allows a scalar, scalar reference, glob, array, or array reference as the thing to read
instead of a file handle.
It's not advised to pass a filehandle to "data" as it will read the entire contents of the
file rather than one line at a time if you set it via "fh".
extract
my ( $foo, $bar, $baz ) = $p->extract( qw[ foo bar baz ] );
Extracts a list of fields out of the last row read. The field names must correspond to
the field names bound either via "bind_fields" or "bind_header".
fetchrow_array
my @values = $p->fetchrow_array;
Reads a row from the file and returns an array or array reference of the fields.
fetchrow_hashref
my $record = $p->fetchrow_hashref;
print "Name = ", $record->{'name'}, "\n";
Reads a line of the file and returns it as a hash reference. The keys of the hashref are
the field names bound via "bind_fields" or "bind_header". If you do not bind fields prior
to calling this method, the "bind_header" method will be implicitly called for you.
fetchrow_object
while ( my $object = $p->fetchrow_object ) {
my $id = $object->id;
my $name = $object->naem; # <-- this will throw a runtime error
}
This will return the next data record as a Text::RecordParser::Object object that has
read-only accessor methods of the field names and any aliases. This allows you to enforce
field names, further helping ensure that your code is reading the input file correctly.
That is, if you are using the "fetchrow_hashref" method to read each line, you may
misspell the hash key and introduce a bug in your code. With this method, Perl will throw
an error if you attempt to read a field not defined in the file's headers. Additionally,
any defined field aliases will be created as additional accessor methods.
fetchall_arrayref
my $records = $p->fetchall_arrayref;
for my $record ( @$records ) {
print "Name = ", $record->[0], "\n";
}
my $records = $p->fetchall_arrayref( { Columns => {} } );
for my $record ( @$records ) {
print "Name = ", $record->{'name'}, "\n";
}
Like DBI's fetchall_arrayref, returns an arrayref of arrayrefs. Also accepts optional "{
Columns => {} }" argument to return an arrayref of hashrefs.
fetchall_hashref
my $records = $p->fetchall_hashref('id');
for my $id ( keys %$records ) {
my $record = $records->{ $id };
print "Name = ", $record->{'name'}, "\n";
}
Like DBI's fetchall_hashref, this returns a hash reference of hash references. The keys
of the top-level hashref are the field values of the field argument you supply. The field
name you supply can be a field created by a "field_compute".
fh
open my $fh, '<', $file or die $!;
$p->fh( $fh );
Gets or sets the filehandle of the file being read.
field_compute
A callback applied to the fields identified by position (or field name if "bind_fields" or
"bind_header" was called).
The callback will be passed two arguments:
1. The current field
2. A reference to all the other fields, either as an array or hash reference, depending
on the method which you called.
If data looks like this:
parent children
Mike Greg,Peter,Bobby
Carol Marcia,Jane,Cindy
You could split the "children" field into an array reference with the values like so:
$p->field_compute( 'children', sub { [ split /,/, shift() ] } );
The field position or name doesn't actually have to exist, which means you could create
new, computed fields on-the-fly. E.g., if you data looks like this:
1,3,5
32,4,1
9,5,4
You could write a field_compute like this:
$p->field_compute( 3,
sub {
my ( $cur, $others ) = @_;
my $sum;
$sum += $_ for @$others;
return $sum;
}
);
Field "3" will be created as the sum of the other fields. This allows you to further
write:
my $data = $p->fetchall_arrayref;
for my $rec ( @$data ) {
print "$rec->[0] + $rec->[1] + $rec->[2] = $rec->[3]\n";
}
Prints:
1 + 3 + 5 = 9
32 + 4 + 1 = 37
9 + 5 + 4 = 18
field_filter
$p->field_filter( sub { $_ = shift; uc(lc($_)) } );
A callback which is applied to each field. The callback will be passed the current value
of the field. Whatever is passed back will become the new value of the field. The above
example capitalizes field values. To unset the filter, pass in the empty string.
field_list
$p->bind_fields( qw[ foo bar baz ] );
my @fields = $p->field_list;
print join ', ', @fields; # prints "foo, bar, baz"
Returns the fields bound via "bind_fields" (or "bind_header").
field_positions
my %positions = $p->field_positions;
Returns a hash of the fields and their positions bound via "bind_fields" (or
"bind_header"). Mostly for internal use.
field_separator
$p->field_separator("\t"); # splits fields on tabs
$p->field_separator('::'); # splits fields on double colons
$p->field_separator(qr/\s+/); # splits fields on whitespace
my $sep = $p->field_separator; # returns the current separator
Gets and sets the token to use as the field delimiter. Regular expressions can be
specified using qr//. If not specified, it will take a guess based on the filename
extension ("comma" for ".txt," ".dat," or ".csv"; "tab" for ".tab"). The default is a
comma.
filename
$p->filename('/path/to/file.dat');
Gets or sets the complete path to the file to be read. If a file is already opened, then
the handle on it will be closed and a new one opened on the new file.
get_field_aliases
my @aliases = $p->get_field_aliases('name');
Allows you to define alternate names for fields, e.g., sometimes your input file calls
city "town" or "township," sometimes a file uses "Moniker" instead of "name."
header_filter
$p->header_filter( sub { $_ = shift; s/\s+/_/g; lc $_ } );
A callback applied to column header names. The callback will be passed the current value
of the header. Whatever is returned will become the new value of the header. The above
example collapses spaces into a single underscore and lowercases the letters. To unset a
filter, pass in the empty string.
record_separator
$p->record_separator("\n//\n");
$p->field_separator("\n");
Gets and sets the token to use as the record separator. The default is a newline ("\n").
The above example would read a file that looks like this:
field1
field2
field3
//
data1
data2
data3
//
set_field_alias
$p->set_field_alias({
name => 'Moniker,handle', # comma-separated string
city => [ qw( town township ) ], # or anonymous arrayref
});
Allows you to define alternate names for fields, e.g., sometimes your input file calls
city "town" or "township," sometimes a file uses "Moniker" instead of "name."
trim
my $trim_value = $p->trim(1);
Provide "true" argument to remove leading and trailing whitespace from fields. Use a
"false" argument to disable.
AUTHOR
Ken Youens-Clark <kclark@cpan.org>
SOURCE
http://github.com/kyclark/text-recordparser
CREDITS
Thanks to the following:
· Benjamin Tilly
For Text::xSV, the inspirado for this module
· Tim Bunce et al.
For DBI, from which many of the methods were shamelessly stolen
· Tom Aldcroft
For contributing code to make it easy to parse whitespace-delimited data
· Liya Ren
For catching the column-ordering error when parsing with "no-headers"
· Sharon Wei
For catching bug in "extract" that sets up infinite loops
· Lars Thegler
For bug report on missing "script_files" arg in Build.PL
BUGS
None known. Please use http://rt.cpan.org/ for reporting bugs.
LICENSE AND COPYRIGHT
Copyright (C) 2006-10 Ken Youens-Clark. All rights reserved.
This program 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.
This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY;
without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
See the GNU General Public License for more details.