Bug #10128

Quoting problem for arguments of Kernel.system, Kernel.exec on Windows

Added by Maxime Lapointe over 1 year ago.

ruby -v:
ruby 2.0.0p481 (2014-05-08) [x64-mingw32]
2.0.0: UNKNOWN, 2.1: UNKNOWN


On Windows, the methods that call shell commands and receive the parameters individually sometimes do not wrap the parameters sent in quotes.
This results in Windows either splitting the parameter in 2 parameters or, worse, splitting the command in 2 commands.

I joined the file puts_first.bat, which simply outputs the first argument it received. When the parameter received was wrapped by ruby, you will see quotes, it's normal. Just run a irb from from the directory containing that file.

Lines that don't work properly (Using Kernel.exec will do the same thing):

# these write *hello*, then says 'world' is not recognized as an internal or external command
Kernel.system 'puts_first.bat', 'hello&world'
Kernel.system 'puts_first.bat', 'hello|world'

# these write *hello*
Kernel.system 'puts_first.bat', 'hello,world'
Kernel.system 'puts_first.bat', 'hello;world'
Kernel.system 'puts_first.bat', 'hello<world'

# this writes *hello* in the file world
Kernel.system 'puts_first.bat', 'hello>world'

# this writes *helloworld* without the ^
Kernel.system 'puts_first.bat', 'hello^world'

If we add a space anywhere in the above hello world strings, it will work as expected because ruby wraps the parameter if it finds a space.

# Ruby does try to wrap if it finds a double quote, but it escapes double quotes incorrectly:
# this writes *"hello\"world"*, double quotes should be escaped by putting 2 of them, so we should see: *"hello""world"*
Kernel.system 'puts_first.bat', 'hello"world'

# adding a space show the problem in action, this writes *"hello\"*
Kernel.system 'puts_first.bat', 'hello" world'

As a side note, the single quote is not special in Windows, so there is no need to wrap this (but I don't think it's a problem):

# this writes *"hello'world"*
Kernel.system 'puts_first.bat', "hello'world"

This bug also happens in 1.9.3, do you think this be backported?

Unless I did a mistake, this should be all of the problematic characters, I tested with every printable ascii characters.

Thank you

puts_first.bat (18 Bytes) Maxime Lapointe, 08/12/2014 04:01 PM

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