On Thu, 23 Jul 2009 03:25:56 +0200 Christoph Anton Mitterer
<christoph.anton.mitte...@physik.uni-muenchen.de> wrote:
> Package: dash
> Version: 0.5.5.1-2
> Severity: normal
>
> Hi.
>
> I've made some scripts where I pre-process an arbitrary file name for
> some sed- and grep expressions.
> As e.g. . and / (which can occur in filenames) may have special
> meaning to sed and grep, I quote the each character of the filename
> with \ before using it further.
>
> I do about this:
> file='./data/image.oga'
> echo $file
> echo "$file"
>
> file_entry_quoted="$( printf "${file}" | sed --regexp-extended
> 's/(.)/\\\1/g' )"
> echo $file_entry_quoted
> echo "$file_entry_quoted"
>
> under bash this gives me:
> ./data/image.oga
> ./data/image.oga
> \.\/\d\a\t\a\/\i\m\a\g\e\.\o\g\a
> \.\/\d\a\t\a\/\i\m\a\g\e\.\o\g\a
>
> under dash I get:
> ./data/image.oga
> ./data/image.oga
> \.\/\d \/\i\m\g\e\.\o\g
> \.\/\d \/\i\m\g\e\.\o\g
> (that's a tab after the d, the \a seem to be replaced by 0x7)
>
>
> With the `` style of command substitution it's even "worse" in dash,...
> file_entry_quoted="` printf "${file}" | sed --regexp-extended
> 's/(.)/\\\1/g' `"
> In that case,.. each character is replaced by 0x1.
>
> The \a and 0x1 thingy is strange anyway, isn't it?
> But I'd even haven't expected that \t would be replaced as POSIX says
> (
http://www.opengroup.org/onlinepubs/009695399/utilities/xcu_chap02.html#tag_02_06_03
):
> "The results of command substitution shall not be processed for
> further tilde expansion, parameter expansion, command substitution, or
> arithmetic expansion. If a command substitution occurs inside
> double-quotes, field splitting and pathname expansion shall not be
> performed on the results of the substitution."
>
> Or do I misunderstand something?
>
>
> Another thing where bash and dash behave differently is:
> fo='\\'
> echo $fo
> echo "$fo"
>
> gives in bash:
> \\
