regex trick

Alain FELER

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Feb 5, 2006, 5:05:34 PM2/5/06

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I want to replace all ' by \' ? (I need it to do inserts in mysql).
> s = "j'ai"
> s.gsub!(/'/,'\'')
> p s ==> gives j'ai and not j\'ai as I want
Thanks for help.

Stefan Lang

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Feb 5, 2006, 5:16:10 PM2/5/06

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s.gsub!("'", "\\\\'")

should do the trick.

Regards,
Stefan

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Mike Stok

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Feb 5, 2006, 5:18:46 PM2/5/06

to

s.gsub!(/'/, "\\\\'")

or

s.gsub!(/'/) { "\\'" }

will do what you want

Hope this helps,

Mike

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Timothy Hunter

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Feb 5, 2006, 5:21:33 PM2/5/06

to

irb(main):011:0> s = "j'ai"
=> "j'ai"
irb(main):012:0> puts s.sub(/'/) { '\\\'' }
j\'ai
=> nil
irb(main):013:0>

Mike Stok

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Feb 5, 2006, 5:24:29 PM2/5/06

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On 5-Feb-06, at 5:08 PM, Alain FELER wrote:

What interface to MySQL are you using? I know that the Ruby DBI
module allows you to use place-holders in queries, and the DBI layer
does the escaping for you e.g.

dbh.do("INSERT INTO people (id, name, height) VALUES(?, ?, ?)",
nil, "Na'il", 76)

The resulting statement produced by do and sent to the server looks
like this:

INSERT INTO people (id,name,height) VALUES(NULL,'Na\'il',76)

(stolen from http://www.kitebird.com/articles/ruby-dbi.html) or if
you are using the ruby mysql interface then (from http://
www.kitebird.com/articles/ruby-mysql.html)

Using escape_string, the platypus record might be inserted as
follows:

name = dbh.escape_string("platypus")
category = dbh.escape_string("don't know")
dbh.query("INSERT INTO animal (name, category)
VALUES ('" + name + "','" + category + "')")

Alain FELER

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Feb 7, 2006, 4:40:03 PM2/7/06

to

Thank you very much for these four answers, but curiously none works on
my box ! :
Stefan Lang : s.gsub!("'", "\\\\'") gives "j\\'ai" not "j\'ai"
Timothy Hunter : s.sub(/'/) { '\\\'' } gives "j\\'ai"
you : s.gsub!(/'/, "\\\\'") gives "j\\'ai"
and : s.gsub!(/'/) { "\\'" } gives "j'ai"
(I am using ruby 1.8.2.14 on Windows 2000 configured in french,
and I can't even type the {} characters in irb, but I tried with Scite)
However the ruby mysql interface escape_string method works fine.
Thank you.
AF

Mike Stok a écrit :

Eric Hodel

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Feb 7, 2006, 5:16:04 PM2/7/06

to

On Feb 7, 2006, at 1:43 PM, Alain FELER wrote:

> Thank you very much for these four answers, but curiously none
> works on my box ! :

Incorrect. They all work.

p "j\\'ai"
"j\\'ai"
puts "j\\'ai"
j\'ai

> Stefan Lang : s.gsub!("'", "\\\\'") gives "j\\'ai" not "j\'ai"

puts "j'ai".gsub("'", "\\\\'")
j\'ai

> Timothy Hunter : s.sub(/'/) { '\\\'' } gives "j\\'ai"

puts "j'ai".gsub(/'/) { '\\\'' }
j\'ai

> you : s.gsub!(/'/, "\\\\'") gives "j\\'ai"

puts "j'ai".gsub(/'/, "\\\\'")
j\'ai

> and : s.gsub!(/'/) { "\\'" } gives "j'ai"

puts "j'ai".gsub(/'/) { "\\'" }
j\'ai

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Alain FELER

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Feb 7, 2006, 5:20:38 PM2/7/06

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Well, sorry:
> p s gives "j\\'ai"
> puts s gives j\'ai
> print s gives j\'ai
so every four methods work if the result is properly printed
AF

Alain FELER a écrit :