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diff --git a/tools-reference/cut/text.rst b/tools-reference/cut/text.rst new file mode 100644 index 0000000..0d006db --- /dev/null +++ b/tools-reference/cut/text.rst @@ -0,0 +1,37 @@ +cut -- Column Extraction +======================== + +The ``cut`` tool can be used to extract specific columns from files which are +delimited by a particular character or by column numbers. It can be passed +filenames on the commandline; if none are specified, it reads from stdin. + +The ``cut`` tool considers the first character in a line to have index ``1``. +The ``-c``, ``-f`` and ``-b`` switches take a parameter listing the desired +columns. This can be a single value, or a more complex list of values separated +by commas. Each value can be a single number, or two numbers separated by +hyphens representing ``low-high``. If ``low`` is unspecified, it is treated as +the first column. If ``high`` is unspecified, it is treated as being "up to the +last character (inclusive)". + +To select particular characters from each line, use the ``-c`` switch. For +particular bytes (not the same as characters when using multibyte text), use +``-b``. To specify particular fields, use ``-f``. + +When using ``-f``, the field delimiter can be specified using the ``-d`` switch. +The default value is the tab character. The ``-s`` switch instructs ``cut`` to +suppress lines which do not contain any instances of the delimiter -- by default +they are echoed intact. + +For example, to extract the second, fourth and fifth columns in a +comma-delimited file, ignoring lines which contain no commas, one could use: + +.. CODESAMPLE cut-1.ebuild + +To chop the first character off stdin, one could use: + +.. CODESAMPLE cut-2.ebuild + +See `cut-1`_ and `IEEE1003.1-2004-cut`_ for full documentation. + +.. vim: set ft=glep tw=80 sw=4 et spell spelllang=en : .. + |