Text::CSV_PP(3)

NAME
Text::CSV_PP - Text::CSV_XS compatible pure-Perl module

SYNOPSIS
 use Text::CSV_PP;

 $csv = Text::CSV_PP->new();     # create a new object
 # If you want to handle non-ascii char.
 $csv = Text::CSV_PP->new({binary => 1});

 $status = $csv->combine(@columns);    # combine columns into a string
 $line   = $csv->string();             # get the combined string

 $status  = $csv->parse($line);        # parse a CSV string into fields
 @columns = $csv->fields();            # get the parsed fields

 $status       = $csv->status ();      # get the most recent status
 $bad_argument = $csv->error_input (); # get the most recent bad argument
 $diag         = $csv->error_diag ();  # if an error occurred, explains WHY

 $status = $csv->print ($io, $colref); # Write an array of fields
                                       # immediately to a file $io
 $colref = $csv->getline ($io);        # Read a line from file $io,
                                       # parse it and return an array
                                       # ref of fields
 $csv->column_names (@names);          # Set column names for getline_hr ()
 $ref = $csv->getline_hr ($io);        # getline (), but returns a hashref
 $eof = $csv->eof ();                  # Indicate if last parse or
                                       # getline () hit End Of File

 $csv->types(\@t_array);               # Set column types

DESCRIPTION
Text::CSV_PP is a pure-perl module that provides facilities for the composition and decomposition of comma-separated values. This is (almost) compatible with much faster Text::CSV_XS, and mainly used as its fallback module when you use Text::CSV module without having installed Text::CSV_XS. If you don't have any reason to use this module directly, use Text::CSV for speed boost and portability (or maybe Text::CSV_XS when you write an one-off script and don't need to care about portability).

The following caveats are taken from the doc of Text::CSV_XS.

  Embedded newlines
Important Note: The default behavior is to accept only ASCII characters in the range from 0x20 (space) to 0x7E (tilde). This means that the fields can not contain newlines. If your data contains newlines embedded in fields, or characters above 0x7E (tilde), or binary data, you must set "binary => 1" in the call to "new". To cover the widest range of parsing options, you will always want to set binary.

But you still have the problem that you have to pass a correct line to the "parse" method, which is more complicated from the usual point of usage:

 my $csv = Text::CSV_PP->new ({ binary => 1, eol => $/ });
 while (<>) {           #  WRONG!
     $csv->parse ($_);
     my @fields = $csv->fields ();
     }

this will break, as the "while" might read broken lines: it does not care about the quoting. If you need to support embedded newlines, the way to go is to not pass "eol" in the parser (it accepts "\n", "\r", and "\r\n" by default) and then

 my $csv = Text::CSV_PP->new ({ binary => 1 });
 open my $io, "<", $file or die "$file: $!";
 while (my $row = $csv->getline ($io)) {
     my @fields = @$row;
     }

The old(er) way of using global file handles is still supported

 while (my $row = $csv->getline (*ARGV)) { ... }

  Unicode
Unicode is only tested to work with perl-5.8.2 and up.

The simplest way to ensure the correct encoding is used for in- and output is by either setting layers on the filehandles, or setting the "encoding" argument for "csv".

 open my $fh, "<:encoding(UTF-8)", "in.csv"  or die "in.csv: $!";
or
 my $aoa = csv (in => "in.csv",     encoding => "UTF-8");

 open my $fh, ">:encoding(UTF-8)", "out.csv" or die "out.csv: $!";
or
 csv (in => $aoa, out => "out.csv", encoding => "UTF-8");

On parsing (both for "getline" and "parse"), if the source is marked being UTF8, then all fields that are marked binary will also be marked UTF8.

On combining ("print" and "combine"): if any of the combining fields was marked UTF8, the resulting string will be marked as UTF8. Note however that all fields before the first field marked UTF8 and contained 8-bit characters that were not upgraded to UTF8, these will be "bytes" in the resulting string too, possibly causing unexpected errors. If you pass data of different encoding, or you don't know if there is different encoding, force it to be upgraded before you pass them on:

 $csv->print ($fh, [ map { utf8::upgrade (my $x = $_); $x } @data ]);

For complete control over encoding, please use Text::CSV::Encoded:

 use Text::CSV::Encoded;
 my $csv = Text::CSV::Encoded->new ({
     encoding_in  => "iso-8859-1", # the encoding comes into   Perl
     encoding_out => "cp1252",     # the encoding comes out of Perl
     });

 $csv = Text::CSV::Encoded->new ({ encoding  => "utf8" });
 # combine () and print () accept *literally* utf8 encoded data
 # parse () and getline () return *literally* utf8 encoded data

 $csv = Text::CSV::Encoded->new ({ encoding  => undef }); # default
 # combine () and print () accept UTF8 marked data
 # parse () and getline () return UTF8 marked data

METHODS
This whole section is also taken from Text::CSV_XS.

  version ()
(Class method) Returns the current module version.

  new (\%attr)
(Class method) Returns a new instance of Text::CSV_PP. The attributes are described by the (optional) hash ref "\%attr".

 my $csv = Text::CSV_PP->new ({ attributes ... });

The following attributes are available:

eol

 my $csv = Text::CSV_PP->new ({ eol => $/ });
           $csv->eol (undef);
 my $eol = $csv->eol;

The end-of-line string to add to rows for "print" or the record separator for "getline".

When not passed in a parser instance, the default behavior is to accept "\n", "\r", and "\r\n", so it is probably safer to not specify "eol" at all. Passing "undef" or the empty string behave the same.

When not passed in a generating instance, records are not terminated at all, so it is probably wise to pass something you expect. A safe choice for "eol" on output is either $/ or "\r\n".

Common values for "eol" are "\012" ("\n" or Line Feed), "\015\012" ("\r\n" or Carriage Return, Line Feed), and "\015" ("\r" or Carriage Return). The "eol" attribute cannot exceed 7 (ASCII) characters.

If both $/ and "eol" equal "\015", parsing lines that end on only a Carriage Return without Line Feed, will be "parse"d correct.

sep_char

 my $csv = Text::CSV_PP->new ({ sep_char => ";" });
         $csv->sep_char (";");
 my $c = $csv->sep_char;

The char used to separate fields, by default a comma. (","). Limited to a single-byte character, usually in the range from 0x20 (space) to 0x7E (tilde). When longer sequences are required, use "sep".

The separation character can not be equal to the quote character or to the escape character.

sep

 my $csv = Text::CSV_PP->new ({ sep => "\N{FULLWIDTH COMMA}" });
           $csv->sep (";");
 my $sep = $csv->sep;

The chars used to separate fields, by default undefined. Limited to 8 bytes.

When set, overrules "sep_char". If its length is one byte it acts as an alias to "sep_char".

quote_char

 my $csv = Text::CSV_PP->new ({ quote_char => "'" });
         $csv->quote_char (undef);
 my $c = $csv->quote_char;

The character to quote fields containing blanks or binary data, by default the double quote character ("""). A value of undef suppresses quote chars (for simple cases only). Limited to a single-byte character, usually in the range from 0x20 (space) to 0x7E (tilde). When longer sequences are required, use "quote".

"quote_char" can not be equal to "sep_char".

quote

 my $csv = Text::CSV_PP->new ({ quote => "\N{FULLWIDTH QUOTATION MARK}" });
             $csv->quote ("'");
 my $quote = $csv->quote;

The chars used to quote fields, by default undefined. Limited to 8 bytes.

When set, overrules "quote_char". If its length is one byte it acts as an alias to "quote_char".

escape_char

 my $csv = Text::CSV_PP->new ({ escape_char => "\\" });
         $csv->escape_char (undef);
 my $c = $csv->escape_char;

The character to escape certain characters inside quoted fields. This is limited to a single-byte character, usually in the range from 0x20 (space) to 0x7E (tilde).

The "escape_char" defaults to being the double-quote mark ("""). In other words the same as the default "quote_char". This means that doubling the quote mark in a field escapes it:

 "foo","bar","Escape ""quote mark"" with two ""quote marks""","baz"

If you change the "quote_char" without changing the "escape_char", the "escape_char" will still be the double-quote ("""). If instead you want to escape the "quote_char" by doubling it you will need to also change the "escape_char" to be the same as what you have changed the "quote_char" to.

The escape character can not be equal to the separation character.

binary

 my $csv = Text::CSV_PP->new ({ binary => 1 });
         $csv->binary (0);
 my $f = $csv->binary;

If this attribute is 1, you may use binary characters in quoted fields, including line feeds, carriage returns and "NULL" bytes. (The latter could be escaped as ""0".) By default this feature is off.

If a string is marked UTF8, "binary" will be turned on automatically when binary characters other than "CR" and "NL" are encountered. Note that a simple string like "\x{00a0}" might still be binary, but not marked UTF8, so setting "{ binary => 1 }" is still a wise option.

decode_utf8

 my $csv = Text::CSV_PP->new ({ decode_utf8 => 1 });
         $csv->decode_utf8 (0);
 my $f = $csv->decode_utf8;

This attributes defaults to TRUE.

While parsing, fields that are valid UTF-8, are automatically set to be UTF-8, so that

  $csv->parse ("\xC4\xA8\n");

results in

  PV("\304\250"\0) [UTF8 "\x{128}"]

Sometimes it might not be a desired action. To prevent those upgrades, set this attribute to false, and the result will be

  PV("\304\250"\0)

auto_diag

 my $csv = Text::CSV_PP->new ({ auto_diag => 1 });
         $csv->auto_diag (2);
 my $l = $csv->auto_diag;

Set this attribute to a number between 1 and 9 causes "error_diag" to be automatically called in void context upon errors.

In case of error "2012 - EOF", this call will be void.

If "auto_diag" is set to a numeric value greater than 1, it will "die" on errors instead of "warn". If set to anything unrecognized, it will be silently ignored.

Future extensions to this feature will include more reliable auto-detection of "autodie" being active in the scope of which the error occurred which will increment the value of "auto_diag" with 1 the moment the error is detected.

diag_verbose

 my $csv = Text::CSV_PP->new ({ diag_verbose => 1 });
         $csv->diag_verbose (2);
 my $l = $csv->diag_verbose;

Set the verbosity of the output triggered by "auto_diag". Currently only adds the current input-record-number (if known) to the diagnostic output with an indication of the position of the error.

blank_is_undef

 my $csv = Text::CSV_PP->new ({ blank_is_undef => 1 });
         $csv->blank_is_undef (0);
 my $f = $csv->blank_is_undef;

Under normal circumstances, "CSV" data makes no distinction between quoted- and unquoted empty fields. These both end up in an empty string field once read, thus

 1,"",," ",2

is read as

 ("1", "", "", " ", "2")

When writing "CSV" files with either "always_quote" or "quote_empty" set, the unquoted empty field is the result of an undefined value. To enable this distinction when reading "CSV" data, the "blank_is_undef" attribute will cause unquoted empty fields to be set to "undef", causing the above to be parsed as

 ("1", "", undef, " ", "2")

note that this is specifically important when loading "CSV" fields into a database that allows "NULL" values, as the perl equivalent for "NULL" is "undef" in DBI land.

empty_is_undef

 my $csv = Text::CSV_PP->new ({ empty_is_undef => 1 });
         $csv->empty_is_undef (0);
 my $f = $csv->empty_is_undef;

Going one step further than "blank_is_undef", this attribute converts all empty fields to "undef", so

 1,"",," ",2

is read as

 (1, undef, undef, " ", 2)

Note that this effects only fields that are originally empty, not fields that are empty after stripping allowed whitespace. YMMV.

allow_whitespace

 my $csv = Text::CSV_PP->new ({ allow_whitespace => 1 });
         $csv->allow_whitespace (0);
 my $f = $csv->allow_whitespace;

When this option is set to true, the whitespace ("TAB"'s and "SPACE"'s) surrounding the separation character is removed when parsing. If either "TAB" or "SPACE" is one of the three characters "sep_char", "quote_char", or "escape_char" it will not be considered whitespace.

Now lines like:

 1 , "foo" , bar , 3 , zapp

are parsed as valid "CSV", even though it violates the "CSV" specs.

Note that all whitespace is stripped from both start and end of each field. That would make it more than a feature to enable parsing bad "CSV" lines, as

 1,   2.0,  3,   ape  , monkey

will now be parsed as

 ("1", "2.0", "3", "ape", "monkey")

even if the original line was perfectly acceptable "CSV".

allow_loose_quotes

 my $csv = Text::CSV_PP->new ({ allow_loose_quotes => 1 });
         $csv->allow_loose_quotes (0);
 my $f = $csv->allow_loose_quotes;

By default, parsing unquoted fields containing "quote_char" characters like

 1,foo "bar" baz,42

would result in parse error 2034. Though it is still bad practice to allow this format, we cannot help the fact that some vendors make their applications spit out lines styled this way.

If there is really bad "CSV" data, like

 1,"foo "bar" baz",42

or

 1,""foo bar baz"",42

there is a way to get this data-line parsed and leave the quotes inside the quoted field as-is. This can be achieved by setting "allow_loose_quotes" AND making sure that the "escape_char" is not equal to "quote_char".

allow_loose_escapes

 my $csv = Text::CSV_PP->new ({ allow_loose_escapes => 1 });
         $csv->allow_loose_escapes (0);
 my $f = $csv->allow_loose_escapes;

Parsing fields that have "escape_char" characters that escape characters that do not need to be escaped, like:

 my $csv = Text::CSV_PP->new ({ escape_char => "\\" });
 $csv->parse (qq{1,"my bar\'s",baz,42});

would result in parse error 2025. Though it is bad practice to allow this format, this attribute enables you to treat all escape character sequences equal.

allow_unquoted_escape

 my $csv = Text::CSV_PP->new ({ allow_unquoted_escape => 1 });
         $csv->allow_unquoted_escape (0);
 my $f = $csv->allow_unquoted_escape;

A backward compatibility issue where "escape_char" differs from "quote_char" prevents "escape_char" to be in the first position of a field. If "quote_char" is equal to the default """ and "escape_char" is set to "\", this would be illegal:

 1,\0,2

Setting this attribute to 1 might help to overcome issues with backward compatibility and allow this style.

always_quote

 my $csv = Text::CSV_PP->new ({ always_quote => 1 });
         $csv->always_quote (0);
 my $f = $csv->always_quote;

By default the generated fields are quoted only if they need to be. For example, if they contain the separator character. If you set this attribute to 1 then all defined fields will be quoted. ("undef" fields are not quoted, see "blank_is_undef"). This makes it quite often easier to handle exported data in external applications.

quote_space

 my $csv = Text::CSV_PP->new ({ quote_space => 1 });
         $csv->quote_space (0);
 my $f = $csv->quote_space;

By default, a space in a field would trigger quotation. As no rule exists this to be forced in "CSV", nor any for the opposite, the default is true for safety. You can exclude the space from this trigger by setting this attribute to 0.

quote_empty

 my $csv = Text::CSV_PP->new ({ quote_empty => 1 });
         $csv->quote_empty (0);
 my $f = $csv->quote_empty;

By default the generated fields are quoted only if they need to be. An empty (defined) field does not need quotation. If you set this attribute to 1 then empty defined fields will be quoted. ("undef" fields are not quoted, see "blank_is_undef"). See also "always_quote".

quote_binary

 my $csv = Text::CSV_PP->new ({ quote_binary => 1 });
         $csv->quote_binary (0);
 my $f = $csv->quote_binary;

By default, all "unsafe" bytes inside a string cause the combined field to be quoted. By setting this attribute to 0, you can disable that trigger for bytes >= 0x7F.

escape_null or quote_null (deprecated)

 my $csv = Text::CSV_PP->new ({ escape_null => 1 });
         $csv->escape_null (0);
 my $f = $csv->escape_null;

By default, a "NULL" byte in a field would be escaped. This option enables you to treat the "NULL" byte as a simple binary character in binary mode (the "{ binary => 1 }" is set). The default is true. You can prevent "NULL" escapes by setting this attribute to 0.

The default when using the "csv" function is "false".

keep_meta_info

 my $csv = Text::CSV_PP->new ({ keep_meta_info => 1 });
         $csv->keep_meta_info (0);
 my $f = $csv->keep_meta_info;

By default, the parsing of input records is as simple and fast as possible. However, some parsing information - like quotation of the original field - is lost in that process. Setting this flag to true enables retrieving that information after parsing with the methods "meta_info", "is_quoted", and "is_binary" described below. Default is false for performance.

If you set this attribute to a value greater than 9, than you can control output quotation style like it was used in the input of the the last parsed record (unless quotation was added because of other reasons).

 my $csv = Text::CSV_PP->new ({
    binary         => 1,
    keep_meta_info => 1,
    quote_space    => 0,
    });

 my $row = $csv->parse (q{1,,"", ," ",f,"g","h""h",help,"help"});

 $csv->print (*STDOUT, \@row);
 # 1,,, , ,f,g,"h""h",help,help
 $csv->keep_meta_info (11);
 $csv->print (*STDOUT, \@row);
 # 1,,"", ," ",f,"g","h""h",help,"help"

verbatim

 my $csv = Text::CSV_PP->new ({ verbatim => 1 });
         $csv->verbatim (0);
 my $f = $csv->verbatim;

This is a quite controversial attribute to set, but makes some hard things possible.

The rationale behind this attribute is to tell the parser that the normally special characters newline ("NL") and Carriage Return ("CR") will not be special when this flag is set, and be dealt with as being ordinary binary characters. This will ease working with data with embedded newlines.

When "verbatim" is used with "getline", "getline" auto-"chomp"'s every line.

Imagine a file format like

 M^^Hans^Janssen^Klas 2\n2A^Ja^11-06-2007#\r\n

where, the line ending is a very specific "#\r\n", and the sep_char is a "^" (caret). None of the fields is quoted, but embedded binary data is likely to be present. With the specific line ending, this should not be too hard to detect.

By default, Text::CSV_PP' parse function is instructed to only know about "\n" and "\r" to be legal line endings, and so has to deal with the embedded newline as a real "end-of-line", so it can scan the next line if binary is true, and the newline is inside a quoted field. With this option, we tell "parse" to parse the line as if "\n" is just nothing more than a binary character.

For "parse" this means that the parser has no more idea about line ending and "getline" "chomp"s line endings on reading.

types

A set of column types; the attribute is immediately passed to the "types" method.

callbacks

See the "Callbacks" section below.

accessors

To sum it up,

 $csv = Text::CSV_PP->new ();

is equivalent to

 $csv = Text::CSV_PP->new ({
     eol                   => undef, # \r, \n, or \r\n
     sep_char              => ',',
     sep                   => undef,
     quote_char            => '"',
     quote                 => undef,
     escape_char           => '"',
     binary                => 0,
     decode_utf8           => 1,
     auto_diag             => 0,
     diag_verbose          => 0,
     blank_is_undef        => 0,
     empty_is_undef        => 0,
     allow_whitespace      => 0,
     allow_loose_quotes    => 0,
     allow_loose_escapes   => 0,
     allow_unquoted_escape => 0,
     always_quote          => 0,
     quote_empty           => 0,
     quote_space           => 1,
     escape_null           => 1,
     quote_binary          => 1,
     keep_meta_info        => 0,
     verbatim              => 0,
     types                 => undef,
     callbacks             => undef,
     });

For all of the above mentioned flags, an accessor method is available where you can inquire the current value, or change the value

 my $quote = $csv->quote_char;
 $csv->binary (1);

It is not wise to change these settings halfway through writing "CSV" data to a stream. If however you want to create a new stream using the available "CSV" object, there is no harm in changing them.

If the "new" constructor call fails, it returns "undef", and makes the fail reason available through the "error_diag" method.

 $csv = Text::CSV_PP->new ({ ecs_char => 1 }) or
     die "".Text::CSV_PP->error_diag ();

"error_diag" will return a string like

 "INI - Unknown attribute 'ecs_char'"

  known_attributes
 @attr = Text::CSV_PP->known_attributes;
 @attr = Text::CSV_PP::known_attributes;
 @attr = $csv->known_attributes;

This method will return an ordered list of all the supported attributes as described above. This can be useful for knowing what attributes are valid in classes that use or extend Text::CSV_PP.

  print
 $status = $csv->print ($io, $colref);

Similar to "combine" + "string" + "print", but much more efficient. It expects an array ref as input (not an array!) and the resulting string is not really created, but immediately written to the $io object, typically an IO handle or any other object that offers a "print" method.

For performance reasons "print" does not create a result string, so all "string", "status", "fields", and "error_input" methods will return undefined information after executing this method.

If $colref is "undef" (explicit, not through a variable argument) and "bind_columns" was used to specify fields to be printed, it is possible to make performance improvements, as otherwise data would have to be copied as arguments to the method call:

 $csv->bind_columns (\($foo, $bar));
 $status = $csv->print ($fh, undef);

  say
 $status = $csv->say ($io, $colref);

Like "print", but "eol" defaults to "$\".

  print_hr
 $csv->print_hr ($io, $ref);

Provides an easy way to print a $ref (as fetched with "getline_hr") provided the column names are set with "column_names".

It is just a wrapper method with basic parameter checks over

 $csv->print ($io, [ map { $ref->{$_} } $csv->column_names ]);

  combine
 $status = $csv->combine (@fields);

This method constructs a "CSV" record from @fields, returning success or failure. Failure can result from lack of arguments or an argument that contains an invalid character. Upon success, "string" can be called to retrieve the resultant "CSV" string. Upon failure, the value returned by "string" is undefined and "error_input" could be called to retrieve the invalid argument.

  string
 $line = $csv->string ();

This method returns the input to "parse" or the resultant "CSV" string of "combine", whichever was called more recently.

  getline
 $colref = $csv->getline ($io);

This is the counterpart to "print", as "parse" is the counterpart to "combine": it parses a row from the $io handle using the "getline" method associated with $io and parses this row into an array ref. This array ref is returned by the function or "undef" for failure. When $io does not support "getline", you are likely to hit errors.

When fields are bound with "bind_columns" the return value is a reference to an empty list.

The "string", "fields", and "status" methods are meaningless again.

  getline_all
 $arrayref = $csv->getline_all ($io);
 $arrayref = $csv->getline_all ($io, $offset);
 $arrayref = $csv->getline_all ($io, $offset, $length);

This will return a reference to a list of getline ($io) results. In this call, "keep_meta_info" is disabled. If $offset is negative, as with "splice", only the last "abs ($offset)" records of $io are taken into consideration.

Given a CSV file with 10 lines:

 lines call
 ----- ---------------------------------------------------------
 0..9  $csv->getline_all ($io)         # all
 0..9  $csv->getline_all ($io,  0)     # all
 8..9  $csv->getline_all ($io,  8)     # start at 8
 -     $csv->getline_all ($io,  0,  0) # start at 0 first 0 rows
 0..4  $csv->getline_all ($io,  0,  5) # start at 0 first 5 rows
 4..5  $csv->getline_all ($io,  4,  2) # start at 4 first 2 rows
 8..9  $csv->getline_all ($io, -2)     # last 2 rows
 6..7  $csv->getline_all ($io, -4,  2) # first 2 of last  4 rows

  getline_hr
The "getline_hr" and "column_names" methods work together to allow you to have rows returned as hashrefs. You must call "column_names" first to declare your column names.

 $csv->column_names (qw( code name price description ));
 $hr = $csv->getline_hr ($io);
 print "Price for $hr->{name} is $hr->{price} EUR\n";

"getline_hr" will croak if called before "column_names".

Note that "getline_hr" creates a hashref for every row and will be much slower than the combined use of "bind_columns" and "getline" but still offering the same ease of use hashref inside the loop:

 my @cols = @{$csv->getline ($io)};
 $csv->column_names (@cols);
 while (my $row = $csv->getline_hr ($io)) {
     print $row->{price};
     }

Could easily be rewritten to the much faster:

 my @cols = @{$csv->getline ($io)};
 my $row = {};
 $csv->bind_columns (\@{$row}{@cols});
 while ($csv->getline ($io)) {
     print $row->{price};
     }

Your mileage may vary for the size of the data and the number of rows.

  getline_hr_all
 $arrayref = $csv->getline_hr_all ($io);
 $arrayref = $csv->getline_hr_all ($io, $offset);
 $arrayref = $csv->getline_hr_all ($io, $offset, $length);

This will return a reference to a list of getline_hr ($io) results. In this call, "keep_meta_info" is disabled.

  parse
 $status = $csv->parse ($line);

This method decomposes a "CSV" string into fields, returning success or failure. Failure can result from a lack of argument or the given "CSV" string is improperly formatted. Upon success, "fields" can be called to retrieve the decomposed fields. Upon failure calling "fields" will return undefined data and "error_input" can be called to retrieve the invalid argument.

You may use the "types" method for setting column types. See "types"' description below.

  fragment
This function tries to implement RFC7111 (URI Fragment Identifiers for the text/csv Media Type) - http://tools.ietf.org/html/rfc7111

 my $AoA = $csv->fragment ($io, $spec);

In specifications, "*" is used to specify the last item, a dash ("-") to indicate a range. All indices are 1-based: the first row or column has index 1. Selections can be combined with the semi-colon (";").

When using this method in combination with "column_names", the returned reference will point to a list of hashes instead of a list of lists. A disjointed cell-based combined selection might return rows with different number of columns making the use of hashes unpredictable.

 $csv->column_names ("Name", "Age");
 my $AoH = $csv->fragment ($io, "col=3;8");

If the "after_parse" callback is active, it is also called on every line parsed and skipped before the fragment.

row
     row=4
     row=5-7
     row=6-*
     row=1-2;4;6-*

col
     col=2
     col=1-3
     col=4-*
     col=1-2;4;7-*

cell
    In cell-based selection, the comma (",") is used to pair row and column

     cell=4,1

    The range operator ("-") using "cell"s can be used to define top-left and bottom-right "cell" location

     cell=3,1-4,6

    The "*" is only allowed in the second part of a pair

     cell=3,2-*,2    # row 3 till end, only column 2
     cell=3,2-3,*    # column 2 till end, only row 3
     cell=3,2-*,*    # strip row 1 and 2, and column 1

    Cells and cell ranges may be combined with ";", possibly resulting in rows with different number of columns

     cell=1,1-2,2;3,3-4,4;1,4;4,1

    Disjointed selections will only return selected cells. The cells that are not specified will not be included in the returned set, not even as "undef". As an example given a "CSV" like

     11,12,13,...19
     21,22,...28,29
     :            :
     91,...97,98,99

    with "cell=1,1-2,2;3,3-4,4;1,4;4,1" will return:

     11,12,14
     21,22
     33,34
     41,43,44

    Overlapping cell-specs will return those cells only once, So "cell=1,1-3,3;2,2-4,4;2,3;4,2" will return:

     11,12,13
     21,22,23,24
     31,32,33,34
     42,43,44

RFC7111 <http://tools.ietf.org/html/rfc7111> does not allow different types of specs to be combined (either "row" or "col" or "cell"). Passing an invalid fragment specification will croak and set error 2013.

  column_names
Set the "keys" that will be used in the "getline_hr" calls. If no keys (column names) are passed, it will return the current setting as a list.

"column_names" accepts a list of scalars (the column names) or a single array_ref, so you can pass the return value from "getline" too:

 $csv->column_names ($csv->getline ($io));

"column_names" does no checking on duplicates at all, which might lead to unexpected results. Undefined entries will be replaced with the string "\cAUNDEF\cA", so

 $csv->column_names (undef, "", "name", "name");
 $hr = $csv->getline_hr ($io);

Will set "$hr->{"\cAUNDEF\cA"}" to the 1st field, "$hr->{""}" to the 2nd field, and "$hr->{name}" to the 4th field, discarding the 3rd field.

"column_names" croaks on invalid arguments.

  header
This method does NOT work in perl-5.6.x

Parse the CSV header and set "sep", column_names and encoding.

 my @hdr = $csv->header ($fh);
 $csv->header ($fh, { sep_set => [ ";", ",", "|", "\t" ] });
 $csv->header ($fh, { detect_bom => 1, munge_column_names => "lc" });

The first argument should be a file handle.

Assuming that the file opened for parsing has a header, and the header does not contain problematic characters like embedded newlines, read the first line from the open handle then auto-detect whether the header separates the column names with a character from the allowed separator list.

If any of the allowed separators matches, and none of the other allowed separators match, set "sep" to that separator for the current CSV_PP instance and use it to parse the first line, map those to lowercase, and use that to set the instance "column_names":

 my $csv = Text::CSV_PP->new ({ binary => 1, auto_diag => 1 });
 open my $fh, "<", "file.csv";
 binmode $fh; # for Windows
 $csv->header ($fh);
 while (my $row = $csv->getline_hr ($fh)) {
     ...
     }

If the header is empty, contains more than one unique separator out of the allowed set, contains empty fields, or contains identical fields (after folding), it will croak with error 1010, 1011, 1012, or 1013 respectively.

If the header contains embedded newlines or is not valid CSV in any other way, this method will croak and leave the parse error untouched.

A successful call to "header" will always set the "sep" of the $csv object. This behavior can not be disabled.

return value

On error this method will croak.

In list context, the headers will be returned whether they are used to set "column_names" or not.

In scalar context, the instance itself is returned. Note: the values as found in the header will effectively be lost if "set_column_names" is false.

Options

sep_set
     $csv->header ($fh, { sep_set => [ ";", ",", "|", "\t" ] });

    The list of legal separators defaults to "[ ";", "," ]" and can be changed by this option. As this is probably the most often used option, it can be passed on its own as an unnamed argument:

     $csv->header ($fh, [ ";", ",", "|", "\t", "::", "\x{2063}" ]);

    Multi-byte sequences are allowed, both multi-character and Unicode. See "sep".

detect_bom
     $csv->header ($fh, { detect_bom => 1 });

    The default behavior is to detect if the header line starts with a BOM. If the header has a BOM, use that to set the encoding of $fh. This default behavior can be disabled by passing a false value to "detect_bom".

    Supported encodings from BOM are: UTF-8, UTF-16BE, UTF-16LE, UTF-32BE, and UTF-32LE. BOM's also support UTF-1, UTF-EBCDIC, SCSU, BOCU-1, and GB-18030 but Encode does not (yet). UTF-7 is not supported.

    The encoding is set using "binmode" on $fh.

    If the handle was opened in a (correct) encoding, this method will not alter the encoding, as it checks the leading bytes of the first line.

munge_column_names
    This option offers the means to modify the column names into something that is most useful to the application. The default is to map all column names to lower case.

     $csv->header ($fh, { munge_column_names => "lc" });

    The following values are available:

      lc   - lower case
      uc   - upper case
      none - do not change
      \&cb - supply a callback

     $csv->header ($fh, { munge_column_names => sub { fc } });
     $csv->header ($fh, { munge_column_names => sub { "column_".$col++ } });
     $csv->header ($fh, { munge_column_names => sub { lc (s/\W+/_/gr) } });

    As this callback is called in a "map", you can use $_ directly.

set_column_names
     $csv->header ($fh, { set_column_names => 1 });

    The default is to set the instances column names using "column_names" if the method is successful, so subsequent calls to "getline_hr" can return a hash. Disable setting the header can be forced by using a false value for this option.

Validation

When receiving CSV files from external sources, this method can be used to protect against changes in the layout by restricting to known headers (and typos in the header fields).

 my %known = (
     "record key" => "c_rec",
     "rec id"     => "c_rec",
     "id_rec"     => "c_rec",
     "kode"       => "code",
     "code"       => "code",
     "vaule"      => "value",
     "value"      => "value",
     );
 my $csv = Text::CSV_PP->new ({ binary => 1, auto_diag => 1 });
 open my $fh, "<", $source or die "$source: $!";
 $csv->header ($fh, { munge_column_names => sub {
     s/\s+$//;
     s/^\s+//;
     $known{lc $_} or die "Unknown column '$_' in $source";
     }});
 while (my $row = $csv->getline_hr ($fh)) {
     say join "\t", $row->{c_rec}, $row->{code}, $row->{value};
     }

  bind_columns
Takes a list of scalar references to be used for output with "print" or to store in the fields fetched by "getline". When you do not pass enough references to store the fetched fields in, "getline" will fail with error 3006. If you pass more than there are fields to return, the content of the remaining references is left untouched.

 $csv->bind_columns (\$code, \$name, \$price, \$description);
 while ($csv->getline ($io)) {
     print "The price of a $name is \x{20ac} $price\n";
     }

To reset or clear all column binding, call "bind_columns" with the single argument "undef". This will also clear column names.

 $csv->bind_columns (undef);

If no arguments are passed at all, "bind_columns" will return the list of current bindings or "undef" if no binds are active.

Note that in parsing with "bind_columns", the fields are set on the fly. That implies that if the third field of a row causes an error, the first two fields already have been assigned the values of the current row, while the rest will still hold the values of the previous row.

  eof
 $eof = $csv->eof ();

If "parse" or "getline" was used with an IO stream, this method will return true (1) if the last call hit end of file, otherwise it will return false (''). This is useful to see the difference between a failure and end of file.

Note that if the parsing of the last line caused an error, "eof" is still true. That means that if you are not using "auto_diag", an idiom like

 while (my $row = $csv->getline ($fh)) {
     # ...
     }
 $csv->eof or $csv->error_diag;

will not report the error. You would have to change that to

 while (my $row = $csv->getline ($fh)) {
     # ...
     }
 +$csv->error_diag and $csv->error_diag;

  types
 $csv->types (\@tref);

This method is used to force that (all) columns are of a given type. For example, if you have an integer column, two columns with doubles and a string column, then you might do a

 $csv->types ([Text::CSV_PP::IV (),
               Text::CSV_PP::NV (),
               Text::CSV_PP::NV (),
               Text::CSV_PP::PV ()]);

Column types are used only for decoding columns while parsing, in other words by the "parse" and "getline" methods.

You can unset column types by doing a

 $csv->types (undef);

or fetch the current type settings with

 $types = $csv->types ();

IV  Set field type to integer.

NV  Set field type to numeric/float.

PV  Set field type to string.

  fields
 @columns = $csv->fields ();

This method returns the input to "combine" or the resultant decomposed fields of a successful "parse", whichever was called more recently.

Note that the return value is undefined after using "getline", which does not fill the data structures returned by "parse".

  meta_info
 @flags = $csv->meta_info ();

This method returns the "flags" of the input to "combine" or the flags of the resultant decomposed fields of "parse", whichever was called more recently.

For each field, a meta_info field will hold flags that inform something about the field returned by the "fields" method or passed to the "combine" method. The flags are bit-wise-"or"'d like:

" "0x0001
    The field was quoted.

" "0x0002
    The field was binary.

See the "is_***" methods below.

  is_quoted
 my $quoted = $csv->is_quoted ($column_idx);

Where $column_idx is the (zero-based) index of the column in the last result of "parse".

This returns a true value if the data in the indicated column was enclosed in "quote_char" quotes. This might be important for fields where content ",20070108," is to be treated as a numeric value, and where ","20070108"," is explicitly marked as character string data.

This method is only valid when "keep_meta_info" is set to a true value.

  is_binary
 my $binary = $csv->is_binary ($column_idx);

Where $column_idx is the (zero-based) index of the column in the last result of "parse".

This returns a true value if the data in the indicated column contained any byte in the range "[\x00-\x08,\x10-\x1F,\x7F-\xFF]".

This method is only valid when "keep_meta_info" is set to a true value.

  is_missing
 my $missing = $csv->is_missing ($column_idx);

Where $column_idx is the (zero-based) index of the column in the last result of "getline_hr".

 $csv->keep_meta_info (1);
 while (my $hr = $csv->getline_hr ($fh)) {
     $csv->is_missing (0) and next; # This was an empty line
     }

When using "getline_hr", it is impossible to tell if the parsed fields are "undef" because they where not filled in the "CSV" stream or because they were not read at all, as all the fields defined by "column_names" are set in the hash-ref. If you still need to know if all fields in each row are provided, you should enable "keep_meta_info" so you can check the flags.

If "keep_meta_info" is "false", "is_missing" will always return "undef", regardless of $column_idx being valid or not. If this attribute is "true" it will return either 0 (the field is present) or 1 (the field is missing).

A special case is the empty line. If the line is completely empty - after dealing with the flags - this is still a valid CSV line: it is a record of just one single empty field. However, if "keep_meta_info" is set, invoking "is_missing" with index 0 will now return true.

  status
 $status = $csv->status ();

This method returns the status of the last invoked "combine" or "parse" call. Status is success (true: 1) or failure (false: "undef" or 0).

  error_input
 $bad_argument = $csv->error_input ();

This method returns the erroneous argument (if it exists) of "combine" or "parse", whichever was called more recently. If the last invocation was successful, "error_input" will return "undef".

  error_diag
 Text::CSV_PP->error_diag ();
 $csv->error_diag ();
 $error_code               = 0  + $csv->error_diag ();
 $error_str                = "" . $csv->error_diag ();
 ($cde, $str, $pos, $rec, $fld) = $csv->error_diag ();

If (and only if) an error occurred, this function returns the diagnostics of that error.

If called in void context, this will print the internal error code and the associated error message to STDERR.

If called in list context, this will return the error code and the error message in that order. If the last error was from parsing, the rest of the values returned are a best guess at the location within the line that was being parsed. Their values are 1-based. The position currently is index of the byte at which the parsing failed in the current record. It might change to be the index of the current character in a later release. The records is the index of the record parsed by the csv instance. The field number is the index of the field the parser thinks it is currently trying to parse. See examples/csv-check for how this can be used.

If called in scalar context, it will return the diagnostics in a single scalar, a-la $!. It will contain the error code in numeric context, and the diagnostics message in string context.

When called as a class method or a direct function call, the diagnostics are that of the last "new" call.

  record_number
 $recno = $csv->record_number ();

Returns the records parsed by this csv instance. This value should be more accurate than $. when embedded newlines come in play. Records written by this instance are not counted.

  SetDiag
 $csv->SetDiag (0);

Use to reset the diagnostics if you are dealing with errors.

FUNCTIONS
This whole section is also taken from Text::CSV_XS.

  csv
This function is not exported by default and should be explicitly requested:

 use Text::CSV_PP qw( csv );

This is an high-level function that aims at simple (user) interfaces. This can be used to read/parse a "CSV" file or stream (the default behavior) or to produce a file or write to a stream (define the "out" attribute). It returns an array- or hash-reference on parsing (or "undef" on fail) or the numeric value of "error_diag" on writing. When this function fails you can get to the error using the class call to "error_diag"

 my $aoa = csv (in => "test.csv") or
     die Text::CSV_PP->error_diag;

This function takes the arguments as key-value pairs. This can be passed as a list or as an anonymous hash:

 my $aoa = csv (  in => "test.csv", sep_char => ";");
 my $aoh = csv ({ in => $fh, headers => "auto" });

The arguments passed consist of two parts: the arguments to "csv" itself and the optional attributes to the "CSV" object used inside the function as enumerated and explained in "new".

If not overridden, the default option used for CSV is

 auto_diag   => 1
 escape_null => 0

The option that is always set and cannot be altered is

 binary      => 1

As this function will likely be used in one-liners, it allows "quote" to be abbreviated as "quo", and "escape_char" to be abbreviated as "esc" or "escape".

Alternative invocations:

 my $aoa = Text::CSV_PP::csv (in => "file.csv");

 my $csv = Text::CSV_PP->new ();
 my $aoa = $csv->csv (in => "file.csv");

In the latter case, the object attributes are used from the existing object and the attribute arguments in the function call are ignored:

 my $csv = Text::CSV_PP->new ({ sep_char => ";" });
 my $aoh = $csv->csv (in => "file.csv", bom => 1);

will parse using ";" as "sep_char", not ",".

in

Used to specify the source. "in" can be a file name (e.g. "file.csv"), which will be opened for reading and closed when finished, a file handle (e.g. $fh or "FH"), a reference to a glob (e.g. "\*ARGV"), the glob itself (e.g. *STDIN), or a reference to a scalar (e.g. "\q{1,2,"csv"}").

When used with "out", "in" should be a reference to a CSV structure (AoA or AoH) or a CODE-ref that returns an array-reference or a hash-reference. The code-ref will be invoked with no arguments.

 my $aoa = csv (in => "file.csv");

 open my $fh, "<", "file.csv";
 my $aoa = csv (in => $fh);

 my $csv = [ [qw( Foo Bar )], [ 1, 2 ], [ 2, 3 ]];
 my $err = csv (in => $csv, out => "file.csv");

If called in void context without the "out" attribute, the resulting ref will be used as input to a subsequent call to csv:

 csv (in => "file.csv", filter => { 2 => sub { length > 2 }})

will be a shortcut to

 csv (in => csv (in => "file.csv", filter => { 2 => sub { length > 2 }}))

where, in the absence of the "out" attribute, this is a shortcut to

 csv (in  => csv (in => "file.csv", filter => { 2 => sub { length > 2 }}),
      out => *STDOUT)

out

In output mode, the default CSV options when producing CSV are

 eol       => "\r\n"

The "fragment" attribute is ignored in output mode.

"out" can be a file name (e.g. "file.csv"), which will be opened for writing and closed when finished, a file handle (e.g. $fh or "FH"), a reference to a glob (e.g. "\*STDOUT"), or the glob itself (e.g. *STDOUT).

 csv (in => sub { $sth->fetch },            out => "dump.csv");
 csv (in => sub { $sth->fetchrow_hashref }, out => "dump.csv",
      headers => $sth->{NAME_lc});

When a code-ref is used for "in", the output is generated per invocation, so no buffering is involved. This implies that there is no size restriction on the number of records. The "csv" function ends when the coderef returns a false value.

encoding

If passed, it should be an encoding accepted by the ":encoding()" option to "open". There is no default value. This attribute does not work in perl 5.6.x. "encoding" can be abbreviated to "enc" for ease of use in command line invocations.

If "encoding" is set to the literal value "auto", the method "header" will be invoked on the opened stream to check if there is a BOM and set the encoding accordingly. This is equal to passing a true value in the option "detect_bom".

detect_bom

If "detect_bom" is given, the method "header" will be invoked on the opened stream to check if there is a BOM and set the encoding accordingly.

"detect_bom" can be abbreviated to "bom".

This is the same as setting "encoding" to "auto".

Note that as "header" is invoked, its default is to also set the headers.

headers

If this attribute is not given, the default behavior is to produce an array of arrays.

If "headers" is supplied, it should be an anonymous list of column names, an anonymous hashref, a coderef, or a literal flag: "auto", "lc", "uc", or "skip".

skip
    When "skip" is used, the header will not be included in the output.

     my $aoa = csv (in => $fh, headers => "skip");

auto
    If "auto" is used, the first line of the "CSV" source will be read as the list of field headers and used to produce an array of hashes.

     my $aoh = csv (in => $fh, headers => "auto");

lc  If "lc" is used, the first line of the "CSV" source will be read as the list of field headers mapped to lower case and used to produce an array of hashes. This is a variation of "auto".

     my $aoh = csv (in => $fh, headers => "lc");

uc  If "uc" is used, the first line of the "CSV" source will be read as the list of field headers mapped to upper case and used to produce an array of hashes. This is a variation of "auto".

     my $aoh = csv (in => $fh, headers => "uc");

CODE
    If a coderef is used, the first line of the "CSV" source will be read as the list of mangled field headers in which each field is passed as the only argument to the coderef. This list is used to produce an array of hashes.

     my $aoh = csv (in      => $fh,
                    headers => sub { lc ($_[0]) =~ s/kode/code/gr });

    this example is a variation of using "lc" where all occurrences of "kode" are replaced with "code".

ARRAY
    If "headers" is an anonymous list, the entries in the list will be used as field names. The first line is considered data instead of headers.

     my $aoh = csv (in => $fh, headers => [qw( Foo Bar )]);
     csv (in => $aoa, out => $fh, headers => [qw( code description price )]);

HASH
    If "headers" is an hash reference, this implies "auto", but header fields for that exist as key in the hashref will be replaced by the value for that key. Given a CSV file like

     post-kode,city,name,id number,fubble
     1234AA,Duckstad,Donald,13,"X313DF"

    using

     csv (headers => { "post-kode" => "pc", "id number" => "ID" }, ...

    will return an entry like

     { pc     => "1234AA",
       city   => "Duckstad",
       name   => "Donald",
       ID     => "13",
       fubble => "X313DF",
       }

See also "munge_column_names" and "set_column_names".

munge_column_names

If "munge_column_names" is set, the method "header" is invoked on the opened stream with all matching arguments to detect and set the headers.

"munge_column_names" can be abbreviated to "munge".

key

If passed, will default "headers" to "auto" and return a hashref instead of an array of hashes.

 my $ref = csv (in => "test.csv", key => "code");

with test.csv like

 code,product,price,color
 1,pc,850,gray
 2,keyboard,12,white
 3,mouse,5,black

will return

  { 1   => {
        code    => 1,
        color   => 'gray',
        price   => 850,
        product => 'pc'
        },
    2   => {
        code    => 2,
        color   => 'white',
        price   => 12,
        product => 'keyboard'
        },
    3   => {
        code    => 3,
        color   => 'black',
        price   => 5,
        product => 'mouse'
        }
    }

fragment

Only output the fragment as defined in the "fragment" method. This option is ignored when generating "CSV". See "out".

Combining all of them could give something like

 use Text::CSV_PP qw( csv );
 my $aoh = csv (
     in       => "test.txt",
     encoding => "utf-8",
     headers  => "auto",
     sep_char => "|",
     fragment => "row=3;6-9;15-*",
     );
 say $aoh->[15]{Foo};

sep_set

If "sep_set" is set, the method "header" is invoked on the opened stream to detect and set "sep_char" with the given set.

"sep_set" can be abbreviated to "seps".

Note that as "header" is invoked, its default is to also set the headers.

set_column_names

If "set_column_names" is passed, the method "header" is invoked on the opened stream with all arguments meant for "header".

  Callbacks
Callbacks enable actions triggered from the inside of Text::CSV_PP.

While most of what this enables can easily be done in an unrolled loop as described in the "SYNOPSIS" callbacks can be used to meet special demands or enhance the "csv" function.

error
     $csv->callbacks (error => sub { $csv->SetDiag (0) });

    the "error" callback is invoked when an error occurs, but only when "auto_diag" is set to a true value. A callback is invoked with the values returned by "error_diag":

     my ($c, $s);

     sub ignore3006
     {
         my ($err, $msg, $pos, $recno, $fldno) = @_;
         if ($err == 3006) {
             # ignore this error
             ($c, $s) = (undef, undef);
             Text::CSV_PP->SetDiag (0);
             }
         # Any other error
         return;
         } # ignore3006

     $csv->callbacks (error => \&ignore3006);
     $csv->bind_columns (\$c, \$s);
     while ($csv->getline ($fh)) {
         # Error 3006 will not stop the loop
         }

after_parse
     $csv->callbacks (after_parse => sub { push @{$_[1]}, "NEW" });
     while (my $row = $csv->getline ($fh)) {
         $row->[-1] eq "NEW";
         }

    This callback is invoked after parsing with "getline" only if no error occurred. The callback is invoked with two arguments: the current "CSV" parser object and an array reference to the fields parsed.

    The return code of the callback is ignored unless it is a reference to the string "skip", in which case the record will be skipped in "getline_all".

     sub add_from_db
     {
         my ($csv, $row) = @_;
         $sth->execute ($row->[4]);
         push @$row, $sth->fetchrow_array;
         } # add_from_db

     my $aoa = csv (in => "file.csv", callbacks => {
         after_parse => \&add_from_db });

    This hook can be used for validation:

    FAIL
        Die if any of the records does not validate a rule:

         after_parse => sub {
             $_[1][4] =~ m/^[0-9]{4}\s?[A-Z]{2}$/ or
                 die "5th field does not have a valid Dutch zipcode";
             }

    DEFAULT
        Replace invalid fields with a default value:

         after_parse => sub { $_[1][2] =~ m/^\d+$/ or $_[1][2] = 0 }

    SKIP
        Skip records that have invalid fields (only applies to "getline_all"):

         after_parse => sub { $_[1][0] =~ m/^\d+$/ or return \"skip"; }

before_print
     my $idx = 1;
     $csv->callbacks (before_print => sub { $_[1][0] = $idx++ });
     $csv->print (*STDOUT, [ 0, $_ ]) for @members;

    This callback is invoked before printing with "print" only if no error occurred. The callback is invoked with two arguments: the current "CSV" parser object and an array reference to the fields passed.

    The return code of the callback is ignored.

     sub max_4_fields
     {
         my ($csv, $row) = @_;
         @$row > 4 and splice @$row, 4;
         } # max_4_fields

     csv (in => csv (in => "file.csv"), out => *STDOUT,
         callbacks => { before print => \&max_4_fields });

    This callback is not active for "combine".

Callbacks for csv ()

The "csv" allows for some callbacks that do not integrate in XS internals but only feature the "csv" function.

  csv (in        => "file.csv",
       callbacks => {
           filter       => { 6 => sub { $_ > 15 } },    # first
           after_parse  => sub { say "AFTER PARSE";  }, # first
           after_in     => sub { say "AFTER IN";     }, # second
           on_in        => sub { say "ON IN";        }, # third
           },
       );

  csv (in        => $aoh,
       out       => "file.csv",
       callbacks => {
           on_in        => sub { say "ON IN";        }, # first
           before_out   => sub { say "BEFORE OUT";   }, # second
           before_print => sub { say "BEFORE PRINT"; }, # third
           },
       );

filter
    This callback can be used to filter records. It is called just after a new record has been scanned. The callback accepts a hashref where the keys are the index to the row (the field number, 1-based) and the values are subs to return a true or false value.

     csv (in => "file.csv", filter => {
                3 => sub { m/a/ },       # third field should contain an "a"
                5 => sub { length > 4 }, # length of the 5th field minimal 5
                });

     csv (in => "file.csv", filter => "not_blank");
     csv (in => "file.csv", filter => "not_empty");
     csv (in => "file.csv", filter => "filled");

    If the keys to the filter hash contain any character that is not a digit it will also implicitly set "headers" to "auto" unless "headers" was already passed as argument. When headers are active, returning an array of hashes, the filter is not applicable to the header itself.

     csv (in => "file.csv", filter => { foo => sub { $_ > 4 }});

    All sub results should match, as in AND.

    The context of the callback sets $_ localized to the field indicated by the filter. The two arguments are as with all other callbacks, so the other fields in the current row can be seen:

     filter => { 3 => sub { $_ > 100 ? $_[1][1] =~ m/A/ : $_[1][6] =~ m/B/ }}

    If the context is set to return a list of hashes ("headers" is defined), the current record will also be available in the localized %_:

     filter => { 3 => sub { $_ > 100 && $_{foo} =~ m/A/ && $_{bar} < 1000  }}

    If the filter is used to alter the content by changing $_, make sure that the sub returns true in order not to have that record skipped:

     filter => { 2 => sub { $_ = uc }}

    will upper-case the second field, and then skip it if the resulting content evaluates to false. To always accept, end with truth:

     filter => { 2 => sub { $_ = uc; 1 }}

    Predefined filters

    Given a file like (line numbers prefixed for doc purpose only):

     1:1,2,3
     2:
     3:,
     4:""
     5:,,
     6:, ,
     7:"",
     8:" "
     9:4,5,6

    not_blank
        Filter out the blank lines

        This filter is a shortcut for

         filter => { 0 => sub { @{$_[1]} > 1 or
                     defined $_[1][0] && $_[1][0] ne "" } }

        Due to the implementation, it is currently impossible to also filter lines that consists only of a quoted empty field. These lines are also considered blank lines.

        With the given example, lines 2 and 4 will be skipped.

    not_empty
        Filter out lines where all the fields are empty.

        This filter is a shortcut for

         filter => { 0 => sub { grep { defined && $_ ne "" } @{$_[1]} } }

        A space is not regarded being empty, so given the example data, lines 2, 3, 4, 5, and 7 are skipped.

    filled
        Filter out lines that have no visible data

        This filter is a shortcut for

         filter => { 0 => sub { grep { defined && m/\S/ } @{$_[1]} } }

        This filter rejects all lines that not have at least one field that does not evaluate to the empty string.

        With the given example data, this filter would skip lines 2 through 8.

after_in
    This callback is invoked for each record after all records have been parsed but before returning the reference to the caller. The hook is invoked with two arguments: the current "CSV" parser object and a reference to the record. The reference can be a reference to a HASH or a reference to an ARRAY as determined by the arguments.

    This callback can also be passed as an attribute without the "callbacks" wrapper.

before_out
    This callback is invoked for each record before the record is printed. The hook is invoked with two arguments: the current "CSV" parser object and a reference to the record. The reference can be a reference to a HASH or a reference to an ARRAY as determined by the arguments.

    This callback can also be passed as an attribute without the "callbacks" wrapper.

    This callback makes the row available in %_ if the row is a hashref. In this case %_ is writable and will change the original row.

on_in
    This callback acts exactly as the "after_in" or the "before_out" hooks.

    This callback can also be passed as an attribute without the "callbacks" wrapper.

    This callback makes the row available in %_ if the row is a hashref. In this case %_ is writable and will change the original row. So e.g. with

      my $aoh = csv (
          in      => \"foo\n1\n2\n",
          headers => "auto",
          on_in   => sub { $_{bar} = 2; },
          );

    $aoh will be:

      [ { foo => 1,
          bar => 2,
          }
        { foo => 2,
          bar => 2,
          }
        ]

csv The function "csv" can also be called as a method or with an existing Text::CSV_PP object. This could help if the function is to be invoked a lot of times and the overhead of creating the object internally over and over again would be prevented by passing an existing instance.

     my $csv = Text::CSV_PP->new ({ binary => 1, auto_diag => 1 });

     my $aoa = $csv->csv (in => $fh);
     my $aoa = csv (in => $fh, csv => $csv);

    both act the same. Running this 20000 times on a 20 lines CSV file, showed a 53% speedup.

DIAGNOSTICS
This section is also taken from Text::CSV_XS.

If an error occurs, "$csv->error_diag" can be used to get information on the cause of the failure. Note that for speed reasons the internal value is never cleared on success, so using the value returned by "error_diag" in normal cases - when no error occurred - may cause unexpected results.

If the constructor failed, the cause can be found using "error_diag" as a class method, like "Text::CSV_PP->error_diag".

The "$csv->error_diag" method is automatically invoked upon error when the contractor was called with "auto_diag" set to 1 or 2, or when autodie is in effect. When set to 1, this will cause a "warn" with the error message, when set to 2, it will "die". "2012 - EOF" is excluded from "auto_diag" reports.

Errors can be (individually) caught using the "error" callback.

The errors as described below are available. I have tried to make the error itself explanatory enough, but more descriptions will be added. For most of these errors, the first three capitals describe the error category:

•   INI

    Initialization error or option conflict.

•   ECR

    Carriage-Return related parse error.

•   EOF

    End-Of-File related parse error.

•   EIQ

    Parse error inside quotation.

•   EIF

    Parse error inside field.

•   ECB

    Combine error.

•   EHR

    HashRef parse related error.

And below should be the complete list of error codes that can be returned:

•   1001 "INI - sep_char is equal to quote_char or escape_char"

    The separation character cannot be equal to the quotation character or to the escape character, as this would invalidate all parsing rules.

•   1002 "INI - allow_whitespace with escape_char or quote_char SP or TAB"

    Using the "allow_whitespace" attribute when either "quote_char" or "escape_char" is equal to "SPACE" or "TAB" is too ambiguous to allow.

•   1003 "INI - \r or \n in main attr not allowed"

    Using default "eol" characters in either "sep_char", "quote_char", or "escape_char" is not allowed.

•   1004 "INI - callbacks should be undef or a hashref"

    The "callbacks" attribute only allows one to be "undef" or a hash reference.

•   1005 "INI - EOL too long"

    The value passed for EOL is exceeding its maximum length (16).

•   1006 "INI - SEP too long"

    The value passed for SEP is exceeding its maximum length (16).

•   1007 "INI - QUOTE too long"

    The value passed for QUOTE is exceeding its maximum length (16).

•   1008 "INI - SEP undefined"

    The value passed for SEP should be defined and not empty.

•   1010 "INI - the header is empty"

    The header line parsed in the "header" is empty.

•   1011 "INI - the header contains more than one valid separator"

    The header line parsed in the "header" contains more than one (unique) separator character out of the allowed set of separators.

•   1012 "INI - the header contains an empty field"

    The header line parsed in the "header" is contains an empty field.

•   1013 "INI - the header contains nun-unique fields"

    The header line parsed in the "header" contains at least two identical fields.

•   1014 "INI - header called on undefined stream"

    The header line cannot be parsed from an undefined sources.

•   2010 "ECR - QUO char inside quotes followed by CR not part of EOL"

    When "eol" has been set to anything but the default, like "\r\t\n", and the "\r" is following the second (closing) "quote_char", where the characters following the "\r" do not make up the "eol" sequence, this is an error.

•   2011 "ECR - Characters after end of quoted field"

    Sequences like "1,foo,"bar"baz,22,1" are not allowed. "bar" is a quoted field and after the closing double-quote, there should be either a new-line sequence or a separation character.

•   2012 "EOF - End of data in parsing input stream"

    Self-explaining. End-of-file while inside parsing a stream. Can happen only when reading from streams with "getline", as using "parse" is done on strings that are not required to have a trailing "eol".

•   2013 "INI - Specification error for fragments RFC7111"

    Invalid specification for URI "fragment" specification.

•   2021 "EIQ - NL char inside quotes, binary off"

    Sequences like "1,"foo\nbar",22,1" are allowed only when the binary option has been selected with the constructor.

•   2022 "EIQ - CR char inside quotes, binary off"

    Sequences like "1,"foo\rbar",22,1" are allowed only when the binary option has been selected with the constructor.

•   2023 "EIQ - QUO character not allowed"

    Sequences like ""foo "bar" baz",qu" and "2023,",2008-04-05,"Foo, Bar",\n" will cause this error.

•   2024 "EIQ - EOF cannot be escaped, not even inside quotes"

    The escape character is not allowed as last character in an input stream.

•   2025 "EIQ - Loose unescaped escape"

    An escape character should escape only characters that need escaping.

    Allowing the escape for other characters is possible with the attribute "allow_loose_escape".

•   2026 "EIQ - Binary character inside quoted field, binary off"

    Binary characters are not allowed by default. Exceptions are fields that contain valid UTF-8, that will automatically be upgraded if the content is valid UTF-8. Set "binary" to 1 to accept binary data.

•   2027 "EIQ - Quoted field not terminated"

    When parsing a field that started with a quotation character, the field is expected to be closed with a quotation character. When the parsed line is exhausted before the quote is found, that field is not terminated.

•   2030 "EIF - NL char inside unquoted verbatim, binary off"

•   2031 "EIF - CR char is first char of field, not part of EOL"

•   2032 "EIF - CR char inside unquoted, not part of EOL"

•   2034 "EIF - Loose unescaped quote"

•   2035 "EIF - Escaped EOF in unquoted field"

•   2036 "EIF - ESC error"

•   2037 "EIF - Binary character in unquoted field, binary off"

•   2110 "ECB - Binary character in Combine, binary off"

•   2200 "EIO - print to IO failed. See errno"

•   3001 "EHR - Unsupported syntax for column_names ()"

•   3002 "EHR - getline_hr () called before column_names ()"

•   3003 "EHR - bind_columns () and column_names () fields count mismatch"

•   3004 "EHR - bind_columns () only accepts refs to scalars"

•   3006 "EHR - bind_columns () did not pass enough refs for parsed fields"

•   3007 "EHR - bind_columns needs refs to writable scalars"

•   3008 "EHR - unexpected error in bound fields"

•   3009 "EHR - print_hr () called before column_names ()"

•   3010 "EHR - print_hr () called with invalid arguments"

SEE ALSO
Text::CSV_XS, Text::CSV

I got many regexp bases from <http://www.din.or.jp/~ohzaki/perl.htm>

AUTHOR
Makamaka Hannyaharamitu, <makamaka[at]cpan.org>

Text::CSV_XS was written by <joe[at]ispsoft.de> and maintained by <h.m.brand[at]xs4all.nl>.

Text::CSV was written by <alan[at]mfgrtl.com>.

COPYRIGHT AND LICENSE
Copyright 2005-2015 by Makamaka Hannyaharamitu, <makamaka[at]cpan.org>

Most of the code and doc is directly taken from the pure perl part of Text::CSV_XS.

Copyright (C) 2007-2016 H.Merijn Brand. All rights reserved. Copyright (C) 1998-2001 Jochen Wiedmann. All rights reserved. Copyright (C) 1997 Alan Citterman. All rights reserved.

This library is free software; you can redistribute it and/or modify it under the same terms as Perl itself.