c8df88ddad
Do the same for pkg-descr files. Approved by: markm
24 lines
1.1 KiB
Text
24 lines
1.1 KiB
Text
A plethora of tools exist that operate as filters: they get data from a
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source, operate on this data, and write possibly modified data to a
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destination. In the Unix world, these tools can be chained using a
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technique called pipelining, where the output of one filter is connected
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to the input of another filter. Some non-Unix worlds are reported to
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have similar provisions.
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To create Perl modules for filter functionality seems trivial at first.
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Just open the input file, read and process it, and write output to a
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destination file. But for really reusable modules this approach is too
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simple. A reusable module should not read and write files itself, but
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rely on the calling program to provide input as well as to handle the
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output.
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Text::Filter is a base class for modules that have in common that they
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process text lines by reading from some source (usually a file),
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manipulating the contents and writing something back to some destination
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(usually some other file).
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This module can be used 'as is', but its real power shows when used to
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derive modules from it.
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-Anton
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<tobez@FreeBSD.org>
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