[#44776] [ruby-trunk - Bug #6385][Open] mtime vie File.stat(filename).utime vs File.open(filename, 'r').mtime in Windows — "kolmanv (Kolman Vornovitsky)" <kolmanv@...>

9 messages 2012/05/01

[#44782] [ruby-trunk - Bug #6387][Open] 1.9.3p194 crashed on require in ubuntu — "ywen (Yi Wen)" <hayafirst@...>

12 messages 2012/05/01

[#44795] [ruby-trunk - Bug #6391][Open] Segment Fault while execute make_encmake.rb for Ruby 1.9.3 P194 ( MinGW64) — "raylinn@... (ray linn)" <raylinn@...>

13 messages 2012/05/02

[#44911] [ruby-trunk - Bug #6408][Open] DelegateClass#eql? and <=> don't work as expected — "tenderlovemaking (Aaron Patterson)" <aaron@...>

11 messages 2012/05/06

[#44951] [ruby-trunk - Feature #6414][Open] Destructuring Assignment — "edtsech (Edward Tsech)" <edtsech@...>

14 messages 2012/05/08

[#44958] [ruby-trunk - Feature #6418][Assigned] Supporing a subset of ANSI escape code on Windows — "usa (Usaku NAKAMURA)" <usa@...>

11 messages 2012/05/09

[#45035] [ruby-trunk - Bug #6433][Open] rb_thread_blocking_region(): ubf() function is executed with GVL — ibc (Iñaki Baz Castillo) <ibc@...>

12 messages 2012/05/14

[#45180] [ruby-trunk - Feature #6478][Open] BasicObject#__class__ — "trans (Thomas Sawyer)" <transfire@...>

14 messages 2012/05/22

[#45193] [ruby-trunk - Feature #6482][Open] Add URI requested to Net::HTTP request and response objects — "drbrain (Eric Hodel)" <drbrain@...7.net>

16 messages 2012/05/23

[#45198] [ruby-trunk - Feature #6483][Open] parametric map — "prijutme4ty (Ilya Vorontsov)" <prijutme4ty@...>

14 messages 2012/05/23

[#45222] [ruby-trunk - Feature #6492][Open] Inflate all HTTP Content-Encoding: deflate, gzip, x-gzip responses by default — "drbrain (Eric Hodel)" <drbrain@...7.net>

23 messages 2012/05/24

[#45252] [ruby-trunk - Feature #6499][Open] Array::zip — "prijutme4ty (Ilya Vorontsov)" <prijutme4ty@...>

14 messages 2012/05/26

[#45272] [ruby-trunk - Feature #6503][Open] Support for the NPN extension to TLS/SSL — "igrigorik (Ilya Grigorik)" <ilya@...>

13 messages 2012/05/27

[#45316] [ruby-trunk - Feature #6515][Open] array.c: added method that verifies if an Array is part of another — "lellisga (Li Ellis Galardo)" <lellisga@...>

14 messages 2012/05/30

[ruby-core:45153] Re: [ruby-trunk - Bug #6474][Open] Substitution bug in String # gsub

From: Mike Stok <mike@...>
Date: 2012-05-20 13:42:17 UTC
List: ruby-core #45153
Maybe you are bing confused by the way irb displays results as double quoted strings.  If you explicitly use puts:

ratdog:~ mike$ irb
1.9.3-p125 :001 > s = 'a&b'
 => "a&b" 
1.9.3-p125 :002 > puts s.gsub '&', '\&'
a&b
 => nil 
1.9.3-p125 :003 > puts s.gsub '&', '\\&'
a&b
 => nil 
1.9.3-p125 :004 > puts s.gsub '&', '\\\&'
a\&b
 => nil 
1.9.3-p125 :005 > puts s.gsub '&', '\\\\&'
a\&b
 => nil 

I like using a block to make this situation less full of backslashes e.g.

1.9.3-p125 :006 > puts s.gsub('&') { '\&' }
a\&b

To see the way irb displays strings consider:

1.9.3-p125 :008 > s = 'a\&b'
 => "a\\&b" 
1.9.3-p125 :009 > puts s
a\&b
 => nil 
1.9.3-p125 :010 > puts s.length
4
 => nil 
1.9.3-p125 :011 > s = "a\tb"
 => "a\tb" 
1.9.3-p125 :012 > puts s
a	b
 => nil 

Hope this helps,

Mike

On 2012-05-20, at 9:19 AM, hadmut (Hadmut Danisch) wrote:

> 
> Issue #6474 has been reported by hadmut (Hadmut Danisch).
> 
> ----------------------------------------
> Bug #6474: Substitution bug in String # gsub
> https://bugs.ruby-lang.org/issues/6474
> 
> Author: hadmut (Hadmut Danisch)
> Status: Open
> Priority: Normal
> Assignee: 
> Category: 
> Target version: 
> ruby -v: ruby 1.9.3p0 (2011-10-30 revision 33570) [x86_64-linux]
> 
> 
> Hi,
> 
> I need to replace all occurences of &  with \&  in a String (generating LaTeX input). 
> 
> However, gsub has a problem with unescaping the \ character in the replacement string:
> 
> irb(main):001:0> "a&b"
> => "a&b"
> irb(main):002:0> "a&b".gsub('&','\&')
> => "a&b"
> irb(main):003:0> "a&b".gsub('&','\\&')
> => "a&b"
> irb(main):004:0> "a&b".gsub('&','\\\&')
> => "a\\&b"
> irb(main):005:0> "a&b".gsub('&','\\\\&')
> => "a\\&b"
> 
> So it always inserts either zero or two \ characters, but never a single one. Not possible to generate "a\&b"
> 
> 
> regards
> 
> 
> 
> 
> -- 
> http://bugs.ruby-lang.org/

-- 

Mike Stok <mike@stok.ca>
http://www.stok.ca/~mike/

The "`Stok' disclaimers" apply.





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