Re: Array parameter expansion with non-space-IFS on bash-3/4

[DennisW]

On Nov 27, 3:47 pm, Freddy Vulto <fvu...@gmail.com> wrote:
> I noticed different behaviour between bash-3 and bash-4 when
> performing parameter expansion on an array with IFS set to a non-space
> value.  For example, on bash-3.2.39, I get:
>
>     $ bash -c 'IFS=:; printf "<%s>\n" "${@/q}"' x a b
>     <a b>
>
> Whereas on bash-4.0.33, I get:
>
>     $ bash -c 'IFS=:; printf "<%s>\n" "${@/q}"' x a b
>     <a>
>     <b>
>
> Bash-4 seems to give the desired result (leave the array intact), but
> it's a bug on bash-3?
>
> Regards,
>
> Freddy Vultohttp://fvue.nl

It seems to be a combination of IFS and pattern substitution. There's
another difference shown below with an intact IFS, but referring to a
string as an array.

Using this script:

#!/bin/bash
v=(a b c)
w="d e f"
printf "<%s>\n" "${w[@]/q}"
IFS=X
printf "<%s>\n" "${v[@]/q}"

In Bash 4.0.33(1)-release I get:

<d e f>
<a>
<b>
<c>

In Bash 3.2.49(23)-release I get:

<d>
<e>
<f>
<a b c>

Other combinations of array vs. string, changing IFS or not, and/or
not using pattern substitution produce the same results in the two
versions.

----

Dennis

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