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STRIP stage v1.1
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Pipelines v1.9
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_BOTH_____________________________________________________________
>>__STRIP__|__________________________________________________________________|________><
| _BOTH_____ |
|_|__________|__ _________ __ __________________________________ __|
|_LEADING__| |_ANYCase_| |_charrange_______ __ __________ __|
|_TRAILING_| |_STRing_ _string_| |_maxstrip_|
|_ANYof__|
Notes:
(1) The maxstrip operand cannot be specified without specifying other operands.
Use
the STRIP stage to remove leading and/or trailing characters from input
records. STRIP reads records from its primary input stream; removes the
specified characters and writes the resulting records to its primary output stream.
If no operands are specified; STRIP removes leading and trailing whitespace
from the records (both space (X’20) and tab (X’09) characters are considered to
be whitespace). If you only specify the BOTH, LEADING or TRAILING operands;
whitespace is removed from both ends of the records, the beginning of the
records or the end of the records, respectively. With additional operands; the
specified target characters are removed.
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BOTH
removes consecutive occurrences of the specified
characters from the beginning and the end of input records. This is the
default.
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LEADING
removes consecutive
occurrences of the specified characters from the beginning of input records.
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TRAILING
removes consecutive
occurrences of the specified characters from the end of input records.
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ANYCase
specifies that charrange or string is compared with the input record in uppercase. In effect
this means that a non-case-sensitive comparison is made when selecting
characters that are to be removed.
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charrange
is a character
range. STRIP removes leading or trailing occurrences of any of the characters
in the range.
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STRing
specifies that the string operand is a literal string of
characters to remove.
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ANYof
specifies that the string operand is a list of characters
to remove. STRIP removes leading or trailing occurrences of any of the
characters in the list.
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string
is a string to
locate.
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maxstrip
specifies the maximum
number of occurrences of the target character(s) or string to remove.
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The following streams are used by the STRIP
stage:
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Stream
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Action
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Primary input
stream
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STRIP reads records from its primary input
stream.
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Primary output
stream
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After removing the specified characters from the records read from its
primary input stream; STRIP writes the resulting records to its primary
output stream.
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1)
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STRIP does not delay the records.
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2)
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If the STRIP stage discovers that its
primary input or output streams are not connected, the STRIP stage ends.
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3)
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STRIP copies any null input records to its
primary output stream.
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4)
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If all the characters
in a record are removed, STRIP writes a null record to its primary output
stream
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5)
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STRIP verifies that its secondary input
and output streams are not connected and then begins execution.
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The
following example utilises the STRIP stage command in a pipeline which
determines the number of bytes that could be saved by removing trailing
whitespace:
pipe < myfile.txt
| locate .* Discard blank-lines.
| xlate w-1;* x20 @ x09 @ .* Change spaces/tabs to at(@) chars.
| split before str /@/ .* Split at each at(@), start new record.
| strip trailing anyof /@/ .* Reduce records to length zero.
| nlocate 1 .* Select only null/empty records.
| count .* Count the records.
| specs /The number of bytes which could be saved is:/ 1 1-* nw
| cons .* Display the result.
Reference
the following links for additional information:
CHOP, JOIN, PAD, SPECS, SPLIT