dbcolsplittocols - Man Page

split an existing column into multiple new columns

Synopsis

dbcolsplittocols [-E] [-C ElementSeparator] column

Description

Create new columns by splitting an existing column. The fragments of the column are each divided by ElementSeparator (default is underscore).

This command is the opposite of dbcolmerge. Names of the new columns are given by splitting the name of the existing column. dbcolrename may be useful to set column names.

Input treated as strings and output columns are of type string.

Specify the separator S used to join columns. Usually a signle character, it can also be a regular expression (so, for example, [,_] matches either , or _ as an element separator.) (Defaults to a single underscore.)

-E or --enumerate

Enumerate output columns: rather than assuming the column name uses the element separator, we keep it whole and fill in with indexes starting from 0. (Not currently implemented, but planned. See dbcolsplittorows.)

-N on --new-name

Specify the names of the new columns as a space separated list. (Default is to apply the separator to the name of the column that is being split.)

By default, column a_b will split to columns a and b. If the column is given as ab with option -N 'a b', one will get the same result.

-E or --enumerate

This module also supports the standard fsdb options:

-d: Enable debugging output.
-i or --input InputSource: Read from InputSource, typically a file name, or - for standard input, or (if in Perl) a IO::Handle, Fsdb::IO or Fsdb::BoundedQueue objects.
-o or --output OutputDestination: Write to OutputDestination, typically a file name, or - for standard output, or (if in Perl) a IO::Handle, Fsdb::IO or Fsdb::BoundedQueue objects.
--autorun or --noautorun: By default, programs process automatically, but Fsdb::Filter objects in Perl do not run until you invoke the run() method. The --(no)autorun option controls that behavior within Perl.
--header H: Use H as the full Fsdb header, rather than reading a header from then input.
--help: Show help.
--man: Show full manual.

Sample Usage

Input

    #fsdb      first_last
    John_Heidemann
    Greg_Johnson
    Root
    # this is a simple database
    #  | dbcolrename fullname first_last
    #  | /home/johnh/BIN/DB/dbcol first_last

Command

    cat data.fsdb | dbcolsplittocols first_last

Output

    #fsdb      first_last      first   last
    John_Heidemann  John    Heidemann
    Greg_Johnson    Greg    Johnson
    Root    Root
    # this is a simple database
    #  | dbcolrename fullname first_last
    #  | /home/johnh/BIN/DB/dbcol first_last
    #  | /home/johnh/BIN/DB/dbcolsplittocols first_last

AUTHOR and COPYRIGHT

This program is distributed under terms of the GNU general public license, version 2. See the file COPYING with the distribution for details.

Referenced By

dbcolsplittorows(1), dbfilepivot(1).

2024-08-02 perl v5.40.0 User Contributed Perl Documentation