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Matched by /\B/ in GNU awk

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# 1  
Old 01-03-2010
Matched by /\B/ in GNU awk
My GNU awk's version is 3.1.5, the special regexp operator '\B' can't work as expected.
The document from "The GNU Awk User's Guide"
Quote:
\B
Matches the empty string that occurs between two word-constituent characters. For example, /\Brat\B/ matches ‘crate' but it does not match ‘dirty rat'. ‘\B' is essentially the opposite of ‘\y'.
It's my data file:
Code:
ABCDE
ABCD
ABC
AB
A

replaces all /\B/ with gsub:
Code:
$ awk '{gsub(/\B/,"X")}1' data 
AXBXCXDE
AXBXCD
AXBC
AXB
A

And, the expected result is:
Code:
$ awk '{gsub(/\B/,"X")}1' data 
AXBXCXDXE
AXBXCXD
AXBXC
AXB
A

Last edited by redraiment; 01-04-2010 at 07:22 AM..
# 2  
Old 01-04-2010
This behavior seams to be version specific:

Code:
$ awk --version|head -1
GNU Awk 3.1.5
$ awk 'gsub(/\B/,"X")||1'  data
AXBXCXDE
AXBXCD
AXBC
AXB
A

Code:
% awk --version | head -1
GNU Awk 3.1.7
% awk 'gsub(/\B/,"X")||1'  data
AXBXCXDXE
AXBXCXD
AXBXC
AXB
A

# 3  
Old 01-04-2010
Quote:
Originally Posted by radoulov
This behavior seams to be version specific:

Code:
$ awk --version|head -1
GNU Awk 3.1.5
$ awk 'gsub(/\B/,"X")||1'  data
AXBXCXDE
AXBXCD
AXBC
AXB
A

Code:
% awk --version | head -1
GNU Awk 3.1.7
% awk 'gsub(/\B/,"X")||1'  data
AXBXCXDXE
AXBXCXD
AXBXC
AXB
A

Thank you very much! This bug has been fixed in v3.1.6Smilie
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