Re: read builtin. input processes improperly inheriting IFS setting

[Greg Wooledge]

On Sat, Jul 27, 2013 at 01:34:53AM +0900, David H. wrote:
>     # The test string:
>     $ echo $instring
>     root:x:0:0:root:/root:/bin/bash
> 
>     # Gives incorrect (unexpected) output:
>     $ ( IFS=: read -a strings < <( echo $instring ) ; printf '[%s]\n'
> "${strings[@]}" )
>     [root x 0 0 root /root /bin/bash]

You must quote "$instring" to prevent word splitting by the shell.

  IFS=: read -a strings < <(echo "$instring")

or

  IFS=: read -a strings <<< "$instring"

Your unquoted $instring is being split into fields by bash, which is
operating with IFS=: at that point.  Quoting it avoids this problem.

imadev:~$ instring="root:x:0:0:root:/root:/bin/bash"
imadev:~$ IFS=: read -a strings < <(echo "$instring")
imadev:~$ printf '<%s> ' "${strings[@]}"; echo
<root> <x> <0> <0> <root> </root> </bin/bash>