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Last update: 1997-05-20
9945-2-130
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Topic: awk - escape sequences in ERE constants
Relevant Sections: 4.1.7.8 (6)
Defect Report:
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From: mark@mks.com (Mark Funkenhauser)
Date: Wed, 5 Jul 1995 09:52:40 -0400 (EDT)
Dear Standards Board,
I would like to an request official, binding interpretation
from WG15 concerning the following point in ISO/IEC
9945-2:1993 (POSIX.2).
I'd like an interpretation of how awk should be evaluating the
following ERE constant:
/x[ab\135cd]y/ # note that \135 is the octal escape
# sequence for the ']' character.
Should this be interpreted as
/x[ab]cd]y/ # this matches the string "xacd]y"
or should this be interpreted as (is done historically)
/x[<one of a,b,c,d,\135>]y/ # this matches "x]y"
My reading of subsection (6) lines 1113-1116 indicates that
the former interpretation is correct but this does not conform
to historical practice.
Thank you for your attention to this matter.
Mark Funkenhauser
Interpretation response
------------------------
The standard clearly states the behavior for ERE's in awk, and conforming
implementations must conform to this, even if it does not match some
historic practices. However, concerns have been raised about this which
are being forwarded to the sponsor.
Rationale
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None.
Forwarded to Interpretations group: Jul 6 1995
Proposed resolution forwarded: Aug 11 1995
Finalized: Sept 12 1995