Bug #8136: gsub strange behavior when substituting "\\'"

• Status: Closed
• Assignee: -
• Target version: -
• ruby -v: 2.0.0

[alexeymuranov (Alexey Muranov)]

=begin
s = "\'" # => "\'"
print s # '
"foo".gsub("f", s) # => "oooo"

Can anybody please explain to me why it works like this? Is this a bug?
=end

[Eregon (Benoit Daloze)]

Seems like ' is interpreted as $' ($POSTMATCH) which is in this case 'oo'.

[nobu (Nobuyoshi Nakada)]

• Category set to doc
• Status changed from Open to Closed

This is one of most frequently asked questions.
Though I can't remember a pointer to good explanation, someone would know it.

[alexeymuranov (Alexey Muranov)]

Excuse me, nobu, i have not understood, how can i replace something with a backslash followed by a single quote?

[nobu (Nobuyoshi Nakada)]

=begin
You need more escapes.

"foo".gsub("f", "\\'")
=end

[alexeymuranov (Alexey Muranov)]

nobu (Nobuyoshi Nakada) wrote:

=begin
You need more escapes.

"foo".gsub("f", "\\'")
=end

Thank you, i have not read the documentation carefully. It is still a bit strange to me that a replacement string is not taken literally by default.