$\n doesn't get expanded between double-quotes ['PureMessage.Watchdog': checked]

[fsc-log-rjn]

Configuration Information [Automatically generated, do not change]:
Machine: i486
OS: linux-gnu
Compiler: gcc
Compilation CFLAGS:  -DPROGRAM='bash' -DCONF_HOSTTYPE='i486' 
-DCONF_OSTYPE='linux-gnu' -DCONF_MACHTYPE='i486-pc-linux-gnu' 
-DCONF_VENDOR='pc' -DLOCALEDIR='/usr/share/locale' -DPACKAGE='bash' -DSHELL 
-DHAVE_CONFIG_H   -I.  -I../bash -I../bash/include -I../bash/lib   -g -O2 -Wall
uname output: Linux fsc-log 2.6.28-11-generic #42-Ubuntu SMP Fri Apr 17 
01:57:59 UTC 2009 i686 GNU/Linux
Machine Type: i486-pc-linux-gnu

Bash Version: 3.2
Patch Level: 48
Release Status: release

Description:
Bash allows escape characters to be embedded by using the $'\n'  
syntax. However, unlike all other $variables,
this doesn't work with embedded newlines. I think it should.

Repeat-By:
X="a$'\n'b c"
echo "$X"

expect to see:
a
b c

actually see:
a$'\n'b c


Fix:
$'\n'  should be expanded within double-quotes, like other variables 
are. 
Otherwise, please correct the man-page to make it clearer.

If this is a feature, not a bug, then is there a better way to include 
newlines in a variable-assignment?
The syntaxX="a"$'\n'"b c"will do it, but that is really really 
ugly.


Thanks,

Richard


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Re: $\n doesn't get expanded between double-quotes

[Chris F.A. Johnson]

On Fri, 3 Jul 2009, fsc-log-...@richardneill.org wrote:

> Configuration Information [Automatically generated, do not change]:
> Machine: i486
> OS: linux-gnu
> Compiler: gcc
> Compilation CFLAGS:  -DPROGRAM='bash' -DCONF_HOSTTYPE='i486' 
> -DCONF_OSTYPE='linux-gnu' -DCONF_MACHTYPE='i486-pc-linux-gnu' 
> -DCONF_VENDOR='pc' -DLOCALEDIR='/usr/share/locale' -DPACKAGE='bash' -DSHELL 
> -DHAVE_CONFIG_H   -I.  -I../bash -I../bash/include -I../bash/lib   -g -O2 
> -Wall
> uname output: Linux fsc-log 2.6.28-11-generic #42-Ubuntu SMP Fri Apr 17 
> 01:57:59 UTC 2009 i686 GNU/Linux
> Machine Type: i486-pc-linux-gnu
> 
> Bash Version: 3.2
> Patch Level: 48
> Release Status: release
> 
> Description:
>   Bash allows escape characters to be embedded by using the $'\n'  
> syntax. However, unlike all other $variables,
> this doesn't work with embedded newlines. I think it should.
> 
> Repeat-By:
>   X="a$'\n'b c"
>   echo "$X"
> 
>   expect to see:
>   a
>   b c
> 
>   actually see:
>   a$'\n'b c
> 
> 
> Fix:
>   $'\n'  should be expanded within double-quotes, like other variables 
> are. 
>   Otherwise, please correct the man-page to make it clearer.

   $'\n' is not a variable. As the man page says:

Words of the form $'string' are treated specially.

   Note "Words". Inside double quotes, $'\n' is not a word.


> 
>   If this is a feature, not a bug, then is there a better way to include 
> newlines in a variable-assignment?
>   The syntaxX="a"$'\n'"b c"will do it, but that is really really 
> ugly.

X=$'a\nb c'


-- 
   Chris F.A. Johnson, webmaster 
   ===
   Author:
   Shell Scripting Recipes: A Problem-Solution Approach (2005, Apress)