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Text::CSV_XS - comma-separated values manipulation routines |
Text::CSV_XS - comma-separated values manipulation routines
# Functional interface use Text::CSV_XS qw( csv );
# Read whole file in memory
my $aoa = csv (in => "data.csv"); # as array of array
my $aoh = csv (in => "data.csv",
headers => "auto"); # as array of hash
# Write array of arrays as csv file csv (in => $aoa, out => "file.csv", sep_char=> ";");
# Only show lines where "code" is odd
csv (in => "data.csv", filter => { code => sub { $_ % 2 }});
# Object interface use Text::CSV_XS;
my @rows;
# Read/parse CSV
my $csv = Text::CSV_XS->new ({ binary => 1, auto_diag => 1 });
open my $fh, "<:encoding(utf8)", "test.csv" or die "test.csv: $!";
while (my $row = $csv->getline ($fh)) {
$row->[2] =~ m/pattern/ or next; # 3rd field should match
push @rows, $row;
}
close $fh;
# and write as CSV open $fh, ">:encoding(utf8)", "new.csv" or die "new.csv: $!"; $csv->say ($fh, $_) for @rows; close $fh or die "new.csv: $!";
Text::CSV_XS provides facilities for the composition and decomposition of
comma-separated values. An instance of the Text::CSV_XS class will combine
fields into a CSV string and parse a CSV string into fields.
The module accepts either strings or files as input and support the use of user-specified characters for delimiters, separators, and escapes.
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_XS->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_XS->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 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 the Text::CSV::Encoded manpage:
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
While no formal specification for CSV exists, RFC 4180 1) describes the
common format and establishes text/csv as the MIME type registered with
the IANA. RFC 7111 2 adds fragments to CSV.
Many informal documents exist that describe the CSV format. ``How To: The
Comma Separated Value (CSV) File Format'' 3) provides an overview of the
CSV format in the most widely used applications and explains how it can
best be used and supported.
1) http://tools.ietf.org/html/rfc4180 2) http://tools.ietf.org/html/rfc7111 3) http://www.creativyst.com/Doc/Articles/CSV/CSV01.htm
The basic rules are as follows:
CSV is a delimited data format that has fields/columns separated by the
comma character and records/rows separated by newlines. Fields that contain
a special character (comma, newline, or double quote), must be enclosed in
double quotes. However, if a line contains a single entry that is the empty
string, it may be enclosed in double quotes. If a field's value contains a
double quote character it is escaped by placing another double quote
character next to it. The CSV file format does not require a specific
character encoding, byte order, or line terminator format.
LF=0x0A) or
a carriage return and line feed pair (ASCII/CRLF=0x0D 0x0A), however,
line-breaks may be embedded.
Fields are separated by commas.
Allowable characters within a CSV field include 0x09 (TAB) and the
inclusive range of 0x20 (space) through 0x7E (tilde). In binary mode
all characters are accepted, at least in quoted fields.
A field within CSV must be surrounded by double-quotes to contain a
separator character (comma).
Though this is the most clear and restrictive definition, Text::CSV_XS is way more liberal than this, and allows extension:
0x20 (space) to 0x7E (tilde). Characters outside
this range may or may not work as expected. Multibyte characters, like UTF
U+060C (ARABIC COMMA), U+FF0C (FULLWIDTH COMMA), U+241B (SYMBOL
FOR ESCAPE), U+2424 (SYMBOL FOR NEWLINE), U+FF02 (FULLWIDTH QUOTATION
MARK), and U+201C (LEFT DOUBLE QUOTATION MARK) (to give some examples of
what might look promising) work for newer versions of perl for sep_char,
and quote_char but not for escape_char.
If you use perl-5.8.2 or higher these three attributes are utf8-decoded, to
increase the likelihood of success. This way U+00FE will be allowed as a
quote character.
CSV must be surrounded by double-quotes to make an embedded
double-quote, represented by a pair of consecutive double-quotes, valid. In
binary mode you may additionally use the sequence "0 for representation
of a NULL byte. Using 0x00 in binary mode is just as valid.
Several violations of the above specification may be lifted by passing some
options as attributes to the object constructor.
(Class method) Returns the current module version.
(Class method) Returns a new instance of class Text::CSV_XS. The attributes
are described by the (optional) hash ref \%attr.
my $csv = Text::CSV_XS->new ({ attributes ... });
The following attributes are available:
my $csv = Text::CSV_XS->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 parsed correct.
my $csv = Text::CSV_XS->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.
See also CAVEATS
my $csv = Text::CSV_XS->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.
See also CAVEATS
my $csv = Text::CSV_XS->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.
my $csv = Text::CSV_XS->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.
See also CAVEATS
my $csv = Text::CSV_XS->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.
my $csv = Text::CSV_XS->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.
my $csv = Text::CSV_XS->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)
my $csv = Text::CSV_XS->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.
my $csv = Text::CSV_XS->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.
my $csv = Text::CSV_XS->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.
my $csv = Text::CSV_XS->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.
my $csv = Text::CSV_XS->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.
my $csv = Text::CSV_XS->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.
my $csv = Text::CSV_XS->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_XS->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.
my $csv = Text::CSV_XS->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.
my $csv = Text::CSV_XS->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. (Poor creatures who are better to
use Text::CSV_XS. :)
my $csv = Text::CSV_XS->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.
my $csv = Text::CSV_XS->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.
my $csv = Text::CSV_XS->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.
my $csv = Text::CSV_XS->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.
my $csv = Text::CSV_XS->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_XS->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"
my $csv = Text::CSV_XS->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_XS' 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 chomps line endings on reading.
A set of column types; the attribute is immediately passed to the types method.
See the Callbacks section below.
To sum it up,
$csv = Text::CSV_XS->new ();
is equivalent to
$csv = Text::CSV_XS->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_XS->new ({ ecs_char => 1 }) or
die "".Text::CSV_XS->error_diag ();
error_diag will return a string like
"INI - Unknown attribute 'ecs_char'"
@attr = Text::CSV_CS->known_attributes; @attr = Text::CSV_CS::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_XS.
$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);
A short benchmark
my @data = ("aa" .. "zz");
$csv->bind_columns (\(@data));
$csv->print ($io, [ @data ]); # 11800 recs/sec $csv->print ($io, \@data ); # 57600 recs/sec $csv->print ($io, undef ); # 48500 recs/sec
$status = $csv->say ($io, $colref);
Like print, but eol defaults to $\.
$csv->print_hr ($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 ]);
$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.
$line = $csv->string ();
This method 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, 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.
$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
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. With perl-5.14.2 the comparison for a 100_000 line file with 14 rows:
Rate hashrefs getlines
hashrefs 1.00/s -- -76%
getlines 4.15/s 313% --
$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.
$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.
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=4 row=5-7 row=6-* row=1-2;4;6-*
col=2 col=1-3 col=4-* col=1-2;4;7-*
,) is used to pair row and column
cell=4,1
The range operator (-) using cells 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 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.
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.
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_XS 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_XS->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.
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.
$csv->header ($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.
$csv->header ($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.
$csv->header ($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.
$csv->header ($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.
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_XS->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};
}
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.
$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 (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_XS::IV (),
Text::CSV_XS::NV (),
Text::CSV_XS::NV (),
Text::CSV_XS::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 ();
@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.
@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 0x0002See 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 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.
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.
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.
$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).
$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.
Text::CSV_XS->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.
$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.
$csv->SetDiag (0);
Use to reset the diagnostics if you are dealing with errors.
This function is not exported by default and should be explicitly requested:
use Text::CSV_XS qw( csv );
This is the second draft. This function will stay, but the arguments might change based on user feedback.
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_XS->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
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_XS::csv (in => "file.csv");
my $csv = Text::CSV_XS->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_XS->new ({ sep_char => ";" });
my $aoa = $csv->csv (in => "file.csv", sep_char => ",");
will parse using ; as sep_char, not ,.
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)
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.
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 this attribute is not given, the default behavior is to produce an array of arrays.
If headers is supplied, it should be either an anonymous list of column
names, an anonymous hashref or a flag: auto or skip. When skip is
used, the header will not be included in the output.
my $aoa = csv (in => $fh, headers => "skip");
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");
If headers is an anonymous list, the entries in the list will be used
instead
my $aoh = csv (in => $fh, headers => [qw( Foo Bar )]); csv (in => $aoa, out => $fh, headers => [qw( code description price )]);
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",
}
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'
}
}
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_XS 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};
Callbacks enable actions triggered from the inside of Text::CSV_XS.
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.
$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_XS->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
}
$csv->callbacks (after_parse => sub { push @{$_[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:
after_parse => sub {
$_[1][4] =~ m/^[0-9]{4}\s?[A-Z]{2}$/ or
die "5th field does not have a valid Dutch zipcode";
}
after_parse => sub { $_[1][2] =~ m/^\d+$/ or $_[1][2] = 0 }
after_parse => sub { $_[1][0] =~ m/^\d+$/ or return \"skip"; }
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.
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
},
);
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 { $_ = uc; 1 }}
Predefined filters
Given a file like (line numbers prefixed for doc purpose only):
1:1,2,3 2: 3:, 4:"" 5:,, 6:, , 7:"", 8:" " 9:4,5,6
This filter is a shortcut for
filter => { 0 => sub { @{$_[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.
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 1, 3, 4, 5, and 7 are skipped.
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.
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.
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.
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,
}
]
my $csv = Text::CSV_XS->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.
The arguments to these internal functions are deliberately not described or documented in order to enable the module authors make changes it when they feel the need for it. Using them is highly discouraged as the API may change in future releases.
my $csv = Text::CSV_XS->new ({ binary => 1, auto_diag => 1 });
open my $fh, "<", "file.csv" or die "file.csv: $!";
while (my $row = $csv->getline ($fh)) {
# do something with @$row
}
close $fh or die "file.csv: $!";
my $csv = Text::CSV_XS->new ({ binary => 1, auto_diag => 1 });
open my $fh, "<", "file.csv" or die "file.csv: $!";
# get only the 4th column
my @column = map { $_->[3] } @{$csv->getline_all ($fh)};
close $fh or die "file.csv: $!";
with csv, you could do
my @column = map { $_->[0] }
@{csv (in => "file.csv", fragment => "col=4")};
my $csv = Text::CSV_XS->new ({ keep_meta_info => 1, binary => 1 });
my $sample_input_string =
qq{"I said, ""Hi!""",Yes,"",2.34,,"1.09","\x{20ac}",};
if ($csv->parse ($sample_input_string)) {
my @field = $csv->fields;
foreach my $col (0 .. $#field) {
my $quo = $csv->is_quoted ($col) ? $csv->{quote_char} : "";
printf "%2d: %s%s%s\n", $col, $quo, $field[$col], $quo;
}
}
else {
print STDERR "parse () failed on argument: ",
$csv->error_input, "\n";
$csv->error_diag ();
}
An example for creating CSV files using the print method:
my $csv = Text::CSV_XS->new ({ binary => 1, eol => $/ });
open my $fh, ">", "foo.csv" or die "foo.csv: $!";
for (1 .. 10) {
$csv->print ($fh, [ $_, "$_" ]) or $csv->error_diag;
}
close $fh or die "$tbl.csv: $!";
or using the slower combine and string methods:
my $csv = Text::CSV_XS->new;
open my $csv_fh, ">", "hello.csv" or die "hello.csv: $!";
my @sample_input_fields = (
'You said, "Hello!"', 5.67,
'"Surely"', '', '3.14159');
if ($csv->combine (@sample_input_fields)) {
print $csv_fh $csv->string, "\n";
}
else {
print "combine () failed on argument: ",
$csv->error_input, "\n";
}
close $csv_fh or die "hello.csv: $!";
Rewrite CSV files with ; as separator character to well-formed CSV:
use Text::CSV_XS qw( csv ); csv (in => csv (in => "bad.csv", sep_char => ";"), out => *STDOUT);
As STDOUT is now default in csv, a one-liner converting a UTF-16 CSV
file with BOM and TAB-separation to valid UTF-8 CSV could be:
$ perl -C3 -MText::CSV_XS=csv -we\
'csv(in=>"utf16tab.csv",encoding=>"utf16",sep=>"\t")' >utf8.csv
Dumping a database table can be simple as this (TIMTOWTDI):
my $dbh = DBI->connect (...); my $sql = "select * from foo";
# using your own loop
open my $fh, ">", "foo.csv" or die "foo.csv: $!\n";
my $csv = Text::CSV_XS->new ({ binary => 1, eol => "\r\n" });
my $sth = $dbh->prepare ($sql); $sth->execute;
$csv->print ($fh, $sth->{NAME_lc});
while (my $row = $sth->fetch) {
$csv->print ($fh, $row);
}
# using the csv function, all in memory csv (out => "foo.csv", in => $dbh->selectall_arrayref ($sql));
# using the csv function, streaming with callbacks
my $sth = $dbh->prepare ($sql); $sth->execute;
csv (out => "foo.csv", in => sub { $sth->fetch });
csv (out => "foo.csv", in => sub { $sth->fetchrow_hashref });
Note that this does not discriminate between ``empty'' values and NULL-values
from the database, as both will be the same empty field in CSV. To enable
distinction between the two, use quote_empty.
csv (out => "foo.csv", in => sub { $sth->fetch }, quote_empty => 1);
If the database import utility supports special sequences to insert NULL
values into the database, like MySQL/MariaDB supports \N, use a filter
or a map
csv (out => "foo.csv", in => sub { $sth->fetch },
on_in => sub { $_ //= "\\N" for @{$_[1]} });
while (my $row = $sth->fetch) {
$csv->print ($fh, [ map { $_ // "\\N" } @$row ]);
}
these special sequences are not recognized by Text::CSV_XS on parsing the CSV generated like this, but map and filter are your friends again
while (my $row = $csv->getline ($io)) {
$sth->execute (map { $_ eq "\\N" ? undef : $_ } @$row);
}
csv (in => "foo.csv", filter => { 1 => sub {
$sth->execute (map { $_ eq "\\N" ? undef : $_ } @{$_[1]}); 0; }});
For more extended examples, see the examples/ 1. sub-directory in the
original distribution or the git repository 2.
1. https://github.com/Tux/Text-CSV_XS/tree/master/examples 2. https://github.com/Tux/Text-CSV_XS
The following files can be found there:
CSV and parse beyond
(expected) errors alternative to using the error callback.
$ perl examples/parser-xs.pl bad.csv >good.csv
CSV file and report on its content.
$ csv-check files/utf8.csv
Checked with examples/csv-check 1.5 using Text::CSV_XS 0.81
OK: rows: 1, columns: 2
sep = <,>, quo = <">, bin = <1>
CSV to Microsoft Excel. This requires the Date::Calc manpage
and the Spreadsheet::WriteExcel manpage. The converter accepts various options and
can produce UTF-8 Excel files.
$ csvdiff --html --output=diff.html file1.csv file2.csv
Text::CSV_XS is not designed to detect the characters used to quote and separate fields. The parsing is done using predefined (default) settings. In the examples sub-directory, you can find scripts that demonstrate how you could try to detect these characters yourself.
The import/export from Microsoft Excel is a risky task, according to the
documentation in Text::CSV::Separator. Microsoft uses the system's list
separator defined in the regional settings, which happens to be a semicolon
for Dutch, German and Spanish (and probably some others as well). For the
English locale, the default is a comma. In Windows however, the user is
free to choose a predefined locale, and then change every individual
setting in it, so checking the locale is no solution.
As of version 1.17, a lone first line with just
sep=;
will be recognized and honored when parsing with getline.
error_diag is a (very) good start, but there is more work to be done in this area.
Basic calls should croak or warn on illegal parameters. Errors should be documented.
$csv->meta_info (0, 1, 1, 3, 0, 0); $csv->is_quoted (3, 1);
Metadata Vocabulary for Tabular Data (a W3C editor's draft) could be an example for supporting more metadata.
my @AoH = $csv->parse_file ($filename, { cols => [ 1, 4..8, 12 ]});
Returning something like
[ { fields => [ 1, 2, "foo", 4.5, undef, "", 8 ],
flags => [ ... ],
},
{ fields => [ ... ],
.
},
]
Note that the csv function already supports most of this, but does not return flags. getline_all returns all rows for an open stream, but this will not return flags either. fragment can reduce the required rows or columns, but cannot combine them.
CSV formats, including formats that use TAB, ;,
|, or other non-comma separators.
Examples could be taken from W3C's CSV on the Web: Use Cases and Requirements
No guarantees, but this is what I had in mind some time ago:
The current hard-coding of characters and character ranges makes this code
unusable on EBCDIC systems. Recent work in perl-5.20 might change that.
Opening EBCDIC encoded files on ASCII+ systems is likely to succeed
using Encode's cp37, cp1047, or posix-bc:
open my $fh, "<:encoding(cp1047)", "ebcdic_file.csv" or die "...";
Still under construction ...
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_XS->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:
And below should be the complete list of error codes that can be returned:
allow_whitespace attribute when either
quote_char or escape_char is equal to
SPACE or TAB is too ambiguous to allow.
eol characters in either sep_char,
quote_char, or escape_char is not
allowed.
callbacks attribute only allows one to be undef or
a hash reference.
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.
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.
eol.
1,"foo\nbar",22,1 are allowed only when the binary option
has been selected with the constructor.
1,"foo\rbar",22,1 are allowed only when the binary option
has been selected with the constructor.
"foo "bar" baz",qu and 2023,",2008-04-05,"Foo, Bar",\n
will cause this error.
Allowing the escape for other characters is possible with the attribute allow_loose_escape.
binary to 1 to accept binary data.
the IO::File manpage, the IO::Handle manpage, the IO::Wrap manpage, the Text::CSV manpage, the Text::CSV_PP manpage, the Text::CSV::Encoded manpage, the Text::CSV::Separator manpage, the Text::CSV::Slurp manpage, the Spreadsheet::CSV manpage and the Spreadsheet::Read manpage, and of course the perl manpage.
If you are using perl6, you can have a look at Text::CSV in the perl6
ecosystem, offering the same features.
A CSV parser in JavaScript, also used by W3C, is the multi-threaded in-browser PapaParse.
csvkit is a python CSV parsing toolkit.
Alan Citterman <alan@mfgrtl.com> wrote the original Perl module. Please don't send mail concerning Text::CSV_XS to Alan, who is not involved in the C/XS part that is now the main part of the module.
Jochen Wiedmann <joe@ispsoft.de> rewrote the en- and decoding in C by implementing a simple finite-state machine. He added variable quote, escape and separator characters, the binary mode and the print and getline methods. See ChangeLog releases 0.10 through 0.23.
H.Merijn Brand <h.m.brand@xs4all.nl> cleaned up the code, added the field flags methods, wrote the major part of the test suite, completed the documentation, fixed most RT bugs, added all the allow flags and the csv function. See ChangeLog releases 0.25 and on.
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 and/or modify it under the same terms as Perl itself.
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Text::CSV_XS - comma-separated values manipulation routines |