part - split up a single input file into multiple files according to a column value


    # Split a comma separated file according to the third column
    # keeping and reproducing one line of headers
    perl -w example.csv --header-line=1 --column=3 "--separator=,"

    # Split a tab separated file according to the second column
    perl -w example.tsv --column=2 --separator=009


--out - set the output template

If the output template is not given it is guessed from the name of the first input file or set to part-%s.txt. The %s will be replaced by the column value.

--column - set the column to part on

This is the zero-based number of the column. Multiple columns may be given.

--separator - set the column separator

This is the separator for the columns. It defaults to a tab character ("\t").

--header-line - output the first line into every file

This defines the line as header line which is output into every file. If it is given an argument that string is output as header, otherwise the first line read will be repeated as the header.

If the value is a number, that many lines will be read from the file and used as the header. This makes it impossible to use just a number as the header.

--verbose - output the generated filenames

In normal operation, the program will be silent. If you need to know the generated filenames, the --verbose option will output them.

--filename-sep - set the separator for the filenames

If you prefer a different separator for the filenames than a newline, this option allows you to set it. If the separator looks like an octal number (three digits) it is interpreted as such. Otherwise it will be taken literally. A common use is to set the separator to 000 to separate the files by the zero character if you suspect that your filenames might contain newlines.

It defaults to 012, a newline.

--version - output version information


The program loads the whole input into RAM before writing the output. A future enhancement might be a uniq-like option that tells the program to assume that the input will be grouped according to the parted column so it does not need to allocate memory.

If your memory is not large enough, the following awk one-liner might help you:

    # Example of parting on column 3
    awk -F '{ print $0 > $3 }' FILE


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Copyright (c) 2007-2019 Max Maischein (