csv(n)                          CSV processing                          csv(n)



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NAME
       csv - Procedures to handle CSV data.

SYNOPSIS
       package require Tcl  8.3

       package require csv  ?0.7.3?

       ::csv::iscomplete data

       ::csv::join values {sepChar ,} {delChar "}

       ::csv::joinlist values {sepChar ,} {delChar "}

       ::csv::joinmatrix matrix {sepChar ,} {delChar "}

       ::csv::read2matrix ?-alternate? chan m {sepChar ,} {expand none}

       ::csv::read2queue ?-alternate? chan q {sepChar ,}

       ::csv::report cmd matrix ?chan?

       ::csv::split ?-alternate? line {sepChar ,} {delChar "}

       ::csv::split2matrix ?-alternate? m line {sepChar ,} {expand none}

       ::csv::split2queue ?-alternate? q line {sepChar ,}

       ::csv::writematrix m chan {sepChar ,} {delChar "}

       ::csv::writequeue q chan {sepChar ,} {delChar "}

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DESCRIPTION
       The csv package provides commands to manipulate information in CSV
       FORMAT (CSV = Comma Separated Values).

COMMANDS
       The following commands are available:

       ::csv::iscomplete data
              A predicate checking if the argument data is a complete csv
              record. The result is a boolean flag indicating the completeness
              of the data. The result is true if the data is complete.

       ::csv::join values {sepChar ,} {delChar "}
              Takes a list of values and returns a string in CSV format
              containing these values. The separator character can be defined
              by the caller, but this is optional. The default is ",". The
              quoting character can be defined by the caller, but this is
              optional. The default is '"'.

       ::csv::joinlist values {sepChar ,} {delChar "}
              Takes a list of lists of values and returns a string in CSV
              format containing these values. The separator character can be
              defined by the caller, but this is optional. The default is ",".
              The quoting character can be defined by the caller, but this is
              optional. The default is '"'.  Each element of the outer list is
              considered a record, these are separated by newlines in the
              result. The elements of each record are formatted as usual (via
              ::csv::join).

       ::csv::joinmatrix matrix {sepChar ,} {delChar "}
              Takes a matrix object following the API specified for the
              struct::matrix package and returns a string in CSV format
              containing these values. The separator character can be defined
              by the caller, but this is optional. The default is ",". The
              quoting character can be defined by the caller, but this is
              optional. The default is '"'. Each row of the matrix is
              considered a record, these are separated by newlines in the
              result. The elements of each record are formatted as usual (via
              ::csv::join).

       ::csv::read2matrix ?-alternate? chan m {sepChar ,} {expand none}
              A wrapper around ::csv::split2matrix (see below) reading CSV-
              formatted lines from the specified channel (until EOF) and
              adding them to the given matrix. For an explanation of the
              expand argument see ::csv::split2matrix.

       ::csv::read2queue ?-alternate? chan q {sepChar ,}
              A wrapper around ::csv::split2queue (see below) reading CSV-
              formatted lines from the specified channel (until EOF) and
              adding them to the given queue.

       ::csv::report cmd matrix ?chan?
              A report command which can be used by the matrix methods format
              2string and format 2chan. For the latter this command delegates
              the work to ::csv::writematrix. cmd is expected to be either
              printmatrix or printmatrix2channel. The channel argument, chan,
              has to be present for the latter and must not be present for the
              first.

       ::csv::split ?-alternate? line {sepChar ,} {delChar "}
              converts a line in CSV format into a list of the values
              contained in the line. The character used to separate the values
              from each other can be defined by the caller, via sepChar, but
              this is optional. The default is ",". The quoting character can
              be defined by the caller, but this is optional. The default is
              '"'.

              If the option -alternate is specified a slightly different
              syntax is used to parse the input. This syntax is explained
              below, in the section FORMAT.

       ::csv::split2matrix ?-alternate? m line {sepChar ,} {expand none}
              The same as ::csv::split, but appends the resulting list as a
              new row to the matrix m, using the method add row. The expansion
              mode specified via expand determines how the command handles a
              matrix with less columns than contained in line. The allowed
              modes are:

              none   This is the default mode. In this mode it is the
                     responsibility of the caller to ensure that the matrix
                     has enough columns to contain the full line. If there are
                     not enough columns the list of values is silently
                     truncated at the end to fit.

              empty  In this mode the command expands an empty matrix to hold
                     all columns of the specified line, but goes no further.
                     The overall effect is that the first of a series of lines
                     determines the number of columns in the matrix and all
                     following lines are truncated to that size, as if mode
                     none was set.

              auto   In this mode the command expands the matrix as needed to
                     hold all columns contained in line. The overall effect is
                     that after adding a series of lines the matrix will have
                     enough columns to hold all columns of the longest line
                     encountered so far.

       ::csv::split2queue ?-alternate? q line {sepChar ,}
              The same as ::csv::split, but appending the resulting list as a
              single item to the queue q, using the method put.

       ::csv::writematrix m chan {sepChar ,} {delChar "}
              A wrapper around ::csv::join taking all rows in the matrix m and
              writing them CSV formatted into the channel chan.

       ::csv::writequeue q chan {sepChar ,} {delChar "}
              A wrapper around ::csv::join taking all items in the queue q
              (assumes that they are lists) and writing them CSV formatted
              into the channel chan.

FORMAT
       The format of regular CSV files is specified as

       [1]    Each record of a csv file (comma-separated values, as exported
              e.g. by Excel) is a set of ASCII values separated by ",". For
              other languages it may be ";" however, although this is not
              important for this case as the functions provided here allow any
              separator character.

       [2]    If and only if a value contains itself the separator ",", then
              it (the value) has to be put between "". If the value does not
              contain the separator character then quoting is optional.

       [3]    If a value contains the character ", that character is
              represented by "".

       [4]    The output string "" represents the value ". In other words, it
              is assumed that it was created through rule 3, and only this
              rule, i.e. that the value was not quoted.

       An alternate format definition mainly used by MS products specifies
       that the output string "" is a representation of the empty string. In
       other words, it is assumed that the output was generated out of the
       empty string by quoting it (i.e. rule 2), and not through rule 3. This
       is the only difference between the regular and the alternate format.

       The alternate format is activated through specification of the option
       -alternate to the various split commands.

EXAMPLE
       Using the regular format the record

              123,"123,521.2","Mary says ""Hello, I am Mary""",""


       is parsed into the items

              a) 123
              b) 123,521.2
              c) Mary says "Hello, I am Mary"
              d) "


       Using the alternate format the result is

              a) 123
              b) 123,521.2
              c) Mary says "Hello, I am Mary"
              d) (the empty string)

       instead. As can be seen only item (d) is different, now the empty
       string instead of a ".

BUGS, IDEAS, FEEDBACK
       This document, and the package it describes, will undoubtedly contain
       bugs and other problems.  Please report such in the category csv of the
       Tcllib SF Trackers [http://sourceforge.net/tracker/?group_id=12883].
       Please also report any ideas for enhancements you may have for either
       package and/or documentation.

SEE ALSO
       matrix, queue

KEYWORDS
       csv, matrix, package, queue, tcllib

CATEGORY
       Text processing

COPYRIGHT
       Copyright (c) 2002-2011 Andreas Kupries <andreas_kupries@users.sourceforge.net>




csv                                  0.7.3                              csv(n)
