Hi Achim,

I was wondering how it would behave if the string that is put into a variable contains newlines, backslashes and other things that bash (and other shells) treats specially. The trick with cat and BABEL_TABLE is resistant to this. As in many cases (when I use it at least) the variable come from other parts of the org file and are computed through another language (python in my case) I have such cases that would break.

Also, I think the test coverage for such things is limited for ob-shell.el in the org test suite.
We should probably add some test cases for this, and then make sure it works with your implementation as well.

--paf


On Sun, Jun 22, 2014 at 2:50 PM, Eric Schulte <schulte.eric@gmail.com> wrote:
If this maintains existing functionality, please go ahead and apply it.

Thanks,

Achim Gratz <Stromeko@nexgo.de> writes:

> Achim Gratz writes:
>> Sebastien Vauban writes:
>>> I just ran `make test' and got the same error for
>>> `ob-shell/bash-uses-assoc-arrays'.
>>
>> Yes, that's because not all versions of bash that have associative
>> arrays can parse the bizarre quoting style that goes through a
>> sub-process and here-document that is used to fill in the parameters.
>
> Here's a patch that implements the suggestion and tested to work
> correctly with Cygwin and Linux.
>
> From a79aff65d562e59ed4e01e550224eb96a665c1ae Mon Sep 17 00:00:00 2001
> From: Achim Gratz <Stromeko@Stromeko.DE>
> Date: Thu, 19 Jun 2014 21:23:28 +0200
> Subject: [PATCH] ob-shell: stratify shell variable quoting
>
> * lisp/ob-shell.el: Remove unused defcustom
>   `org-babel-sh-var-quote-fmt'.
>   (org-babel-variable-assignments:bash_array):
>   (org-babel-variable-assignments:bash_assoc): Remove superfluous
>   `mapcar' and double quotes around parameters.
>   (org-babel-sh-var-to-sh): Single-quote the whole string and escape
>   all single quotes in the original string.
> ---
>  lisp/ob-shell.el | 42 ++++++++++++++++++------------------------
>  1 file changed, 18 insertions(+), 24 deletions(-)
>
> diff --git a/lisp/ob-shell.el b/lisp/ob-shell.el
> index 474a8f2..7d87026 100644
> --- a/lisp/ob-shell.el
> +++ b/lisp/ob-shell.el
> @@ -45,12 +45,6 @@ (defcustom org-babel-sh-command shell-file-name
>    :group 'org-babel
>    :type 'string)
>
> -(defcustom org-babel-sh-var-quote-fmt
> -  "$(cat <<'BABEL_TABLE'\n%s\nBABEL_TABLE\n)"
> -  "Format string used to escape variables when passed to shell scripts."
> -  :group 'org-babel
> -  :type 'string)
> -
>  (defcustom org-babel-shell-names
>    '("sh" "bash" "csh" "ash" "dash" "ksh" "mksh" "posh")
>    "List of names of shell supported by babel shell code blocks."
> @@ -113,28 +107,26 @@ (defun org-babel-variable-assignments:sh-generic
>  (defun org-babel-variable-assignments:bash_array
>      (varname values &optional sep hline)
>    "Returns a list of statements declaring the values as a bash array."
> -  (format "unset %s\ndeclare -a %s=( \"%s\" )"
> -     varname varname
> -     (mapconcat 'identity
> -       (mapcar
> -         (lambda (value) (org-babel-sh-var-to-sh value sep hline))
> -         values)
> -       "\" \"")))
> +  (format "unset %s\ndeclare -a %s=( %s )"
> +       varname varname
> +       (mapconcat
> +        (lambda (value) (org-babel-sh-var-to-sh value sep hline))
> +        values
> +        " ")))
>
>  (defun org-babel-variable-assignments:bash_assoc
>      (varname values &optional sep hline)
>    "Returns a list of statements declaring the values as bash associative array."
>    (format "unset %s\ndeclare -A %s\n%s"
>      varname varname
> -    (mapconcat 'identity
> -      (mapcar
> -        (lambda (items)
> -          (format "%s[\"%s\"]=%s"
> -            varname
> -            (org-babel-sh-var-to-sh (car items) sep hline)
> -            (org-babel-sh-var-to-sh (cdr items) sep hline)))
> -        values)
> -      "\n")))
> +    (mapconcat
> +     (lambda (items)
> +       (format "%s[%s]=%s"
> +            varname
> +            (org-babel-sh-var-to-sh (car items) sep hline)
> +            (org-babel-sh-var-to-sh (cdr items) sep hline)))
> +     values
> +     "\n")))
>
>  (defun org-babel-variable-assignments:bash (varname values &optional sep hline)
>    "Represents the parameters as useful Bash shell variables."
> @@ -163,8 +155,10 @@ (defun org-babel-sh-var-to-sh (var &optional sep hline)
>    "Convert an elisp value to a shell variable.
>  Convert an elisp var into a string of shell commands specifying a
>  var of the same value."
> -  (format org-babel-sh-var-quote-fmt
> -       (org-babel-sh-var-to-string var sep hline)))
> +  (concat "'" (replace-regexp-in-string
> +            "'" "'\"'\"'"
> +            (org-babel-sh-var-to-string var sep hline))
> +       "'"))
>
>  (defun org-babel-sh-var-to-string (var &optional sep hline)
>    "Convert an elisp value to a string."
> --
> 2.0.0
>
>
>
> Regards,
> Achim.

--
Eric Schulte
https://cs.unm.edu/~eschulte
PGP: 0x614CA05D (see https://u.fsf.org/yw)




--
--paf