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 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

DESCRIPTION
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.

VERSION
    1.31

This module is compatible with Text::CSV_XS 0.99. (except for diag_verbose and allow_unquoted_escape)

  Unicode (UTF8)
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.

FUNCTIONS
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.

  version ()
(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

  new (\%attr)
(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 "parse"d 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 really 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'"

  print
 $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.

  combine
 $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.

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

This object function 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, 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.

  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

  parse
 $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.

  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 ()".

  getline_hr_all
 $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.

  column_names
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.

  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 ]);

  bind_columns
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
 $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.

  types
 $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.

  fields
 @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 ()".

  meta_info
 @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.

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

  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]

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

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

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

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

  error_diag
 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 occurred, 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.

  SetDiag
 $csv->SetDiag (0);

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

DIAGNOSTICS
If an error occurred, $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 occurred - 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"

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>

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

SEE ALSO
Text::CSV_XS, Text::CSV

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