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

 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 occured, 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

Text::CSV_PP has almost same functions of Text::CSV_XS which provides facilities for the composition and decomposition of comma-separated values. As its name suggests, Text::CSV_XS is a XS module and Text::CSV_PP is a Puer Perl one.

    1.29

This module is compatible with Text::CSV_XS 0.80 and later.

On parsing (both for getline () and parse ()), if the source is marked being UTF8, then parsing that source will mark 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 UTF8.

These methods are almost same as Text::CSV_XS. Most of the documentation was shamelessly copied and replaced from Text::CSV_XS.

See to Text::CSV_XS.

(Class method) Returns the current backend module version. If you want the module version, you can use the VERSION method,

 print Text::CSV->VERSION;      # This module version
 print Text::CSV->version;      # The version of the worker module
                                # same as Text::CSV->backend->version

(Class method) Returns a new instance of Text::CSV_XS. The objects attributes are described by the (optional) hash ref \%attr. Currently the following attributes are available:

eol

An end-of-line string to add to rows. undef is replaced with an empty string. The default is $\. Common values for eol are "\012" (Line Feed) or "\015\012" (Carriage Return, Line Feed). Cannot be longer than 7 (ASCII) characters.

If both $/ and eol equal "\015", parsing lines that end on only a Carriage Return without Line Feed, will be parsed correct. Line endings, whether in $/ or eol, other than undef, "\n", "\r\n", or "\r" are not (yet) supported for parsing.

sep_char

The char used for separating fields, by default a comma. (,). Limited to a single-byte character, usually in the range from 0x20 (space) to 0x7e (tilde).

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

See also CAVEATS in Text::CSV_XS

allow_whitespace

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

So lines like:

  1 , "foo" , bar , 3 , zapp

are now correctly parsed, even though it violates the CSV specs.

Note that all whitespace is stripped from start and end of each field. That would make it more a feature than a way to be able to parse 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 sane CSV.

blank_is_undef

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

 1,"",," ",2

is read as

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

When writing CSV files with always_quote set, the unquoted empty field is the result of an undefined value. To make it possible to also make this distinction when reading CSV data, the blank_is_undef option will cause unquoted empty fields to be set to undef, causing the above to be parsed as

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

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 only effects fields that are realy empty, not fields that are empty after stripping allowed whitespace. YMMV.

quote_char

The char used for quoting fields containing blanks, 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).

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

allow_loose_quotes

By default, parsing fields that have quote_char characters inside an unquoted field, like

 1,foo "bar" baz,42

would result in a parse error. Though it is still bad practice to allow this format, we cannot help there are some vendors that make their applications spit out lines styled like this.

In case there is really bad CSV data, like

 1,"foo "bar" baz",42

or

 1,""foo bar baz"",42

there is a way to get that 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.

escape_char

The character used for escaping certain characters inside quoted fields. Limited to a single-byte character, usually in the range from 0x20 (space) to 0x7e (tilde).

The escape_char defaults to being the literal 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 default quote_char without changing the default escape_char, the escape_char will still be the quote mark. If instead you want to escape the quote_char by doubling it, you will need to change the escape_char to be the same as what you changed the quote_char to.

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

allow_loose_escapes

By default, parsing fields that have escape_char characters that escape characters that do not need to be escaped, like:

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

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

binary

If this attribute is TRUE, you may use binary characters in quoted fields, including line feeds, carriage returns and NULL bytes. (The latter must 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 or 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.

types

A set of column types; this attribute is immediately passed to the types method below. You must not set this attribute otherwise, except for using the types method. For details see the description of the types method below.

always_quote

By default the generated fields are quoted only, if they need to, for example, if they contain the separator. If you set this attribute to a TRUE value, then all defined fields will be quoted. This is typically easier to handle in external applications.

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 option to 0.

quote_null

By default, a NULL byte in a field would be escaped. This attribute 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.

keep_meta_info

By default, the parsing of input lines is as simple and fast as possible. However, some parsing information - like quotation of the original field - is lost in that process. Set this flag to true to be able to retrieve that information after parsing with the methods meta_info (), is_quoted (), and is_binary () described below. Default is false.

verbatim

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

The basic thought behind this 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, that shouldn't be too hard to detect.

By default, Text::CSV' parse function however 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 attribute however, we can 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 idea about line ending anymore, and getline () chomps line endings on reading.

auto_diag

Set to true will cause error_diag () to be automatically be called in void context upon errors.

If set to a value greater than 1, it will die on errors instead of warn.

To check future plans and a difference in XS version, please see to auto_diag in Text::CSV_XS.

To sum it up,

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

is equivalent to

 $csv = Text::CSV_PP->new ({
     quote_char          => '"',
     escape_char         => '"',
     sep_char            => ',',
     eol                 => $\,
     always_quote        => 0,
     quote_space         => 1,
     quote_null          => 1,
     binary              => 0,
     keep_meta_info      => 0,
     allow_loose_quotes  => 0,
     allow_loose_escapes => 0,
     allow_whitespace    => 0,
     blank_is_undef      => 0,
     empty_is_undef      => 0,
     verbatim            => 0,
     auto_diag           => 0,
     });

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

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

It is unwise 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->new ({ ecs_char => 1 }) or
     die "" . Text::CSV->error_diag ();

error_diag () will return a string like

 "INI - Unknown attribute 'ecs_char'"

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

Similar to combine () + string () + print, but more efficient. It expects an array ref as input (not an array!) and the resulting string is not really created (XS version), but immediately written to the $io object, typically an IO handle or any other object that offers a print method. Note, this implies that the following is wrong in perl 5.005_xx and older:

 open FILE, ">", "whatever";
 $status = $csv->print (\*FILE, $colref);

as in perl 5.005 and older, the glob \*FILE is not an object, thus it doesn't have a print method. The solution is to use an IO::File object or to hide the glob behind an IO::Wrap object. See IO::File and IO::Wrap for details.

For performance reasons the print method doesn't create a result string. (If its backend is PP version, result strings are created internally.) In particular the $csv->string (), $csv->status (), $csv-fields ()> and $csv->error_input () methods are meaningless after executing this method.

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

This object function constructs a CSV string from the arguments, returning success or failure. Failure can result from lack of arguments or an argument containing 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 () can be called to retrieve an invalid argument.

 $line = $csv->string ();

This object function returns the input to parse () or the resultant CSV string of combine (), whichever was called more recently.

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

This is the counterpart to print, like parse is the counterpart to combine: It reads a row from the IO object $io using $io->getline () and parses this row into an array ref. This array ref is returned by the function or undef for failure.

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

The $csv->string (), $csv->fields () and $csv->status () methods are meaningless, again.

 $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

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

This object function 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, the value returned by fields () is undefined and error_input () can be called to retrieve the invalid argument.

You may use the types () method for setting column types. See the description below.

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 ().

 $arrayref = $csv->getline_hr_all ($io);

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

Set the keys that will be used in the getline_hr () calls. If no keys (column names) are passed, it'll return the current setting.

column_names () accepts a list of scalars (the column names) or a single array_ref, so you can pass getline ()

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

column_names () does no checking on duplicates at all, which might lead to unwanted 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.

Takes a list of references to scalars to store the fields fetched getline () in. When you don't pass enough references to store the fetched fields in, getline () will fail. If you pass more than there are fields to return, the remaining references are left untouched.

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

 $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.

 $csv->types (\@tref);

This method is used to force that columns are of a given type. For example, if you have an integer column, two double columns 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, 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.

 @columns = $csv->fields ();

This object function returns the input to combine () or the resultant decomposed fields of C 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 ().

 @flags = $csv->meta_info ();

This object function 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 tell something about the field returned by the fields () method or passed to the combine () method. The flags are bitwise-or'd like:

0x0001

The field was quoted.

0x0002

The field was binary.

See the is_*** () methods below.

  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 data where ,20070108, is to be treated as a numeric value, and where ,"20070108", is explicitly marked as character string data.

  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]

 $status = $csv->status ();

This object function returns success (or failure) of combine () or parse (), whichever was called more recently.

 $bad_argument = $csv->error_input ();

This object function returns the erroneous argument (if it exists) of combine () or parse (), whichever was called more recently.

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

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

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

If called in list context, it will return the error code and the error message in that order. If the last error was from parsing, the third value returned is the best guess at the location within the line that was being parsed. It's value is 1-based.

Note: $pos does not show the error point in many cases. It is for conscience's sake.

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.

To achieve this behavior with CSV_PP, the returned diagnostics is blessed object.

 $csv->SetDiag (0);

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

If an error occured, $csv->error_diag () can be used to get more 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 occured - may cause unexpected results.

Note: CSV_PP's diagnostics is different from CSV_XS's:

Text::CSV_XS parses csv strings by dividing one character while Text::CSV_PP by using the regular expressions. That difference makes the different cause of the failure.

Currently these errors are available:

1001 "sep_char is equal to quote_char or escape_char"

The separation character cannot be equal to either the quotation character or the escape character, as that will invalidate all parsing rules.

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

Using allow_whitespace when either escape_char or quote_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.

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

2011 "ECR - Characters after end of quoted field"

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

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

2025 "EIQ - Loose unescaped escape"

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

2027 "EIQ - Quoted field 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",

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"

4002 "EIQ - Unescaped ESC in quoted field"

4003 "EIF - ESC CR"

4004 "EUF - "

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"

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 2005-2010 by Makamaka Hannyaharamitu, <makamaka[at]cpan.org>

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

Text::CSV_XS, Text::CSV

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