On Sat, Jun 27, 2015 at 2:48 PM, Nathan Neulinger <nn...@neulinger.org>
wrote:
> Configuration Information [Automatically generated, do not change]:
> Machine: x86_64
> OS: linux-gnu
> Compiler: gcc
> Compilation CFLAGS: -DPROGRAM='bash' -DCONF_HOSTTYPE='x86_64'
> -DCONF_OSTYPE='linux-gnu' -DCONF_MACHTYPE='x86_64-redhat-linux-gnu'
> -DCONF_VENDOR='redhat' -DLOCALEDIR='/usr/share/locale' -DPACKAGE='bash'
> -DSHELL -DHAVE_CONFIG_H -I. -I. -I./include -I./lib -D_GNU_SOURCE
> -DRECYCLES_PIDS -DDEFAULT_PATH_VALUE='/usr/local/bin:/usr/bin' -O2 -g
> -pipe -Wall -Werror=format-security -Wp,-D_FORTIFY_SOURCE=2 -fexceptions
> -fstack-protector-strong --param=ssp-buffer-size=4 -grecord-gcc-switches
> -m64 -mtune=generic
> uname output: Linux skyhawk.home.neulinger.org 3.19.3-200.fc21.x86_64 #1
> SMP Thu Mar 26 21:39:42 UTC 2015 x86_64 x86_64 x86_64 GNU/Linux
> Machine Type: x86_64-redhat-linux-gnu
>
> Bash Version: 4.3
> Patch Level: 39
> Release Status: release
>
> Description:
>
> If $() includes a case statement nested within it, the parser is
> not matching ) as closing the case,
> but rather the $(. This behavior is different between bash and
> other shells. ksh/busybox
> both process this without error, but I do not know which is
> officially "correct".
>
> Test Case:
> ---------------
> testing=$(
> echo test | while read line; do
> case $line in
> test) echo saw test ;;
> *) echo other ;;
> esac
> done
> )
>
> echo result: $testing
> --------------
>
> Expected output:
>
> result: saw test
>
> Actual output:
>
> parse-bug.sh: line 6: syntax error near unexpected token `;;'
> parse-bug.sh: line 6: ` test) echo saw test ;;'
>
>
> Workaround: Use (test) instead of test) in the nested code
>
>
> Repeat-By:
> Run script with that syntax.
>
>
>
> --
> ------------------------------------------------------------
> Nathan Neulinger nn...@neulinger.org
> Neulinger Consulting (573) 612-1412
>
>
You can use the full syntax of case by surrounding the cases with both
opening and closing parentheses:
testing=$(
echo test | while read line; do
case $line in
(test) echo saw test ;;
(*) echo other ;;
esac
done
)
POSIX shows the opening parentheses as optional, but does not describe
their use or when they might be necessary.
http://pubs.opengroup.org/onlinepubs/9699919799/utilities/V3_chap02.html#tag_18_09_04
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