Bug #10055: Shellwords.shellsplit() does not match POSIX sh behavior for backslashes within double-quoted strings

• Status: Closed
• Assignee: knu (Akinori MUSHA)
• Target version: -
• ruby -v: ruby 2.2.0dev (2014-07-18 trunk 46855) [x86_64-linux]
• Backport: 2.0.0: UNKNOWN, 2.1: UNKNOWN

[charles-dyfis-net (Charles Duffy)]

In POSIX sh, the following commands are identical:

printf '%s\n' hello world
printf "%s\n" hello world

However, Shellwords.shellsplit() parses them differently:

head :001 > require 'shellwords'
 => true
head :002 > Shellwords.shellsplit(%q|printf "%s\\n"|)
 => ["printf", "%sn"]
head :003 > Shellwords.shellsplit(%q|printf '%s\\n'|)
 => ["printf", "%s\\n"]

The documentation for the shellwords module claims that its parser is compatible with Bourne; however, it does not match either this 1970s-era shell language or modern POSIX sh (which is the actual specification used for /bin/sh on modern systems, and incompatible in some respects with original Bourne), both of which preserve backslashes in this context.

[zzak (zzak _)]

• Status changed from Open to Assigned
• Assignee set to knu (Akinori MUSHA)
• Target version set to 2.2.0

knu: do you have any thoughts on this one?

[knu (Akinori MUSHA)]

• Status changed from Assigned to Closed

Applied in changeset r56573.

---

Fix the handling of the backslash in double quotes

• lib/shellwords.rb (Shellwords#shellsplit): Fix the handling of
  the backslash in double quotes to conform to the standard.
  [ruby-core:63807] [Bug #10055]

[knu (Akinori MUSHA)]

That is correct! I've fixed the implementation to conform to the standard.